Book Reviews

In Association with

This page was started at the beginning of September 2005. Reviewers names, book/magazine titles and dates when the reviews were put up on this web site, are as follows:

  • J. Barker: V. Shiva (2008) “Soil not Oil. Climate Change, Peak Oil and Food Security”. Posted 1st July 2009.
  • P. Salonius: Stanton (2003) “The rapid growth of human populations 1750–2000”. Posted early March 2007.
  • A. Bartlett (2006). “Scientific American and the Silent Lie”: “Energy's Future Beyond Carbon”. Scientific American September 2006 issue. Posted mid–February 2007.
  • J. Barker: J. Lovelock (2006) “The Revenge of Gaia”. Beginning of May 2006.
  • J. Barker: “Millennium Ecosystem Assessment” (2005). Beginning of March 2006.
  • J. Barker: J.K. McKee (2003) “Sparing Nature. The conflict between human population growth and earth's biodiversity”. Beginning of March 2006.
  • J. Barker: D. Meadows et al (2004) “Limits to Growth. The 30-year update”. Beginning of September 2005.
  • J. Barker: J. Diamond (2005) “Collapse. How societies choose to fail or succeed. Beginning of September 2005.

The reviews are given in the above order, starting with the most recently posted.

Brief note about each item.

“Soil not Oil. Climate Change, Peak Oil and Food Security” challenges the industrialized world's approach to development in the 'Global South' and offers solutions from the 'Global South'.

“The rapid growth of human populations 1750–2000: histories, consequences, issues” gives a comprehensive account of the growth of national populations and the implications of this growth.

“Energy's Future Beyond Carbon” details how writers in a special issue of the Scientific American magazine put their faith in technological change for solving our climate problems, neglecting the significance of human population growth'.

“The revenge of Gaia” is a study of the self-regulating system consisting of the atmosphere, living things and the ecosystems that contain them, the oceans and the underlying rocks, the system being named 'Gaia'. It shows that through the growth and activities of the human population, with the resulting increase in greenhouse gas emissions, the system is in IMMINENT danger of being destabilised. If that happens, Gaia will have one objective only - to re-stabilise, and in doing so, the needs of the human species will not be considered: if a new stable state is attained, it will be so hot that most of mankind will not survive. A very challenging book which we hope everyone will read.

“Millennium Ecosystem Assessment” and “Sparing Nature” focus on ecosystem and biodiversity decline. We are particularly interested in how these publications regard human population growth. In our view, the first publication (which is in fact a whole series of publications) while being an extremely useful and carefully researched source of information, is seriously flawed in this respect. In contrast the second publication has what we regard as a much more balanced approach to human population growth.

“Sparing Nature”. McKee asserts there is a very close relationship between biodiversity loss and human population growth, and the most important conservation measure we can take is to slow or halt the growth of the human population.

“Limits to growth” uses computer modelling to study the question: how may the expanding global population and material economy interact with and adapt to the earth's limited carrying capacity over the coming decades?

“Collapse” explores what are the unsustainable practices that cause societies to collapse, and is based on a series of case studies.

To go straight to the reviews after the first one, click on the appropriate button:

The Rapid Growth of Human Populations "The silent lie". Energy's Future Beyond Carbon Revenge of Gaia Millennium Ecosystem Assessment Sparing Nature Limits to Growth Collapse 


A summary and review of Vandana Shiva's 2008 book “Soil not oil. Climate change, peak oil and food insecurity”, Zed Books, London

Vandana Shiva, former Indian physicist and environmental campaigner, examines the global environmental situation, challenges the industrialized world's approach to development in the 'Global South' and offers solutions to global problems from the 'Global South'.

In the opening chapter she identifies three intertwined crises face the world:

  • climate – global warming;
  • energy – 'Peak oil' (when the world reaches the highest possible level of oil production);
  • food – rising prices worldwide.

The author considers these crises were created by the 'corporate interests' of industrialized countries. The solutions they propose to deal with the climate change and food crises are often based on continuing existing practices that created the crises in the first place – such as “more fossil–fuel based chemical fertilizers, more non–renewable genetically engineered and hybrid seeds bred to respond to the intensive use of chemicals, more corporate control of food, and more globalized trade” (page 2), and, “false solutions to climate change (such) as industrial biofuels” resulting in the diversion of “food and land from the poor to the non–sustainable energy rich needs of the rich” (page 3). In the poorer nations of the world where still vast numbers of poor peasant farmers live, food production powered by human energy in 'dignified work' (page 4) is being replaced by fossil energy, with “the creation of ‘redundant' or disposable people and, alongside them, the potential for violence and social and political instability” (page 2).

Shiva faces mankind with a choice. Either we can continue on the path “towards a market–centered future, which will make the crisis deeper for the poor and the marginalized and provide a temporary escape for the privileged”, or “we can make a nature–centered, people–centered transition to a fossil fuel–free future, with meaningful work and decent and dignified living for all” (page 4), a transition from an OIL dominated economy to a SOIL dominated economy (hence the title for the book). Shiva asserts that living healthy soil is the foundation for sustainable agricultural production. Ruthless exploitation of the soil had so damaged it that desertification ensues, and this has led to the collapse of civilizations in the past. If we do not make the transition to a soil dominated economy, we will perish.

This transition from oil to soil is an economic, political and cultural transition:

It is first “an economic transition from a fossil–fuel driven, globalized economy”, favouring corporations through “subsidising oil and outsourcing costs”, to a network of local communities “renewable energy–driven, climate change–resilient” (page 6).

Second it is a political transition because it is a transition from undemocratic globalized structures to decentralized democratic local communities.

Third it is a cultural transition from 'deadly consumerism' to reclaiming “our rightful place as cocreators and coproducers with nature” (page 7).

I now give a summary of the book's topics, followed by my citicisms.

Emissions trading and some other solutions advocated by the industrialised world, globalisation and land use.

Shiva develops the theme that industrialized nations policies for tackling the climate change crisis are unsustainable and disproportionately harm developing countries. She deals with emissions trading solutions for reducing greenhouse gas emissions, the largest of these being the European Union Emissions Trading Scheme (ETS). In the European Union, emission targets are set for each country, and each country then divides its allowances between major emitters of carbon dioxide (power utilities, building product manufacturers, etc). Companies that do not use up all their allowances may sell unused allowances (‘carbon trading').

Developing nations can reduce their emissions, by adopting 'clean' technologies. Here industrialized nations assist by investing in the development of these technologies in developing nations, thereby gaining carbon credits to help to offset their own carbon emission reduction targets. This works through the ‘clean development mechanism' (CDM).

Shiva regards carbon trading as something that benefits the industrialized countries rather than the developing world: “by developing green abroad, corporations get credits that allow them to pollute at home” (page 17). She sees the industrialized world as having been given a licence to privatise part of the global climate commons, with considerable financial benefit to companies in those countries.

In the global market, it is very much cheaper to plant trees in poorer countries to absorb carbon dioxide than to reduce emissions at source in the industrialized world. So the burden of cleaning up the atmosphere falls on poor countries. Only a tiny fraction of CDM projects concern renewable energy. The vast majority concern either carbon capture or biomass projects that use up land. This amounts to a 'land grab'. But it is land in developing countries that could have been used for local food production and other community functions and helping to retain biological diversity.

In Shiva's view, carbon trading is ecologically perverse. She argues we need to move away from present day fossil fuel promoted industrial production. And she concludes carbon trading does not stimulate any such drastic transformation.

Shiva goes on to discuss other solutions to the problem of climate change. She first discusses nuclear energy, regarded by many as a ‘clean' energy option. This is not so, she argues. Mining and processing the uranium causes massive pollution, and the costs of disposing nuclear waste are enormous, and she claims cancer rates are up world–wide amongst people who live near nuclear plants.

Focusing on India, agreements with the USA will help India focus on the nuclear solution; at the same time, provisions in the agreements will prevent India itself developing new nuclear technology and prevent India carrying out future nuclear tests, so limiting India's sovereignty over strategic decision making.

Then Shiva considers other, ‘mechanistic' solutions such as seeding oceans with millions of tons of iron, pointing out how each may have disastrous ecological consequences. She sums up her view succinctly and magnificently:

“Playing with Gaia as if she were a LEGO set cannot be the appropriate response at a time when human intervention in the Earth's living systems is threatening our very survival” (page 33).

Globalization – generally accepted as inevitable, or even welcomed by the industrialized world, comes in for close scrutiny. China has seen a massive rise in its carbon dioxide emissions, so that now its total emissions are greater than those of the USA. Consequently some people point a finger at China.

But, first of all, per capita emissions in China by 2006 were only a small fraction of the per capita emissions in the USA.

Second, the emissions in China are largely not through industry there directly helping Chinese people. Energy–intensive production has been out–sourced to China from the USA in the process of globalization, creating the massive Chinese export industry that fills industrialized country's supermarket shelves with goods for their high consumption populations so that, in Shiva's view, much of China's emissions could really be considered as USA emissions.

Globalized industrial economies contrasted with decentralized, low impact economies.

Shiva contrasts the policies and practices of globalized industrial economies (where the “mechanistic, industrial paradigm” (page 43) has “created a planetary ecological imbalance” (page 44), with those of economies she terms “decentralized, low–impact economies” (page 41) that have an ecological paradigm – local community, agriculture–based economies. She maintains that only the latter economies are sustainable. What are the characteristics of these two systems?

The globalized industrialized economies are the corporate–driven economies, where industrial methods produce goods with high energy and other costs. These economies are governed by the laws of the market, laws imposed by the World Bank and the IMF, with market mechanisms that “make high–cost products appear cheap on supermarket shelves”.

It is the controllers of capital who, analysing the climate change emission–reduction problem, make ‘mechanistic assumptions', propose the solutions and ensure corresponding laws are enacted. These solutions actually perpetuate energy–intensive production and consumption (“replacing fossil fuels with other non–sustainable sources of power to power the same systems” (page 44). So, argues Shiva the very systems that created the problem in the first place are programmed to stay in place.

In climate change discussions, Siva alleges, analyses ignore important aspects of the actual situation, namely over extraction and over consumption of energy and injustice to the poor and other life forms (homes and habitats sacrificed). The analyses are 'reductionist': The only energy considered is 'industrial consumptive energy'. So the solutions are restricted, the primary ones being carbon trading, and the substitution of “other consumptive energies” notably nuclear and biofuels, that are developed at “high social and ecological costs”.

The ‘equity' paradigm implicit in the whole approach is that being human and developed means adopting the energy use practices of the rich industrial societies to create equity by pushing the whole world up to the resource use levels of the industrialized world. However, this approach would require the resources of five planets. So the whole debate has been narrowed down to problems and solutions from the perspective of the rich, industrialized, urban societies. The problem is reduced to considering how to control global oil supplies while looking for alternatives that will enable the present economic order to continue.

Rising to rhetorical heights Shiva concludes “the eco–imperialist response to the climate crisis is to grab the remaining resources of the planet……” and use “…violence to exterminate people's rights and people themselves when they get in the way of an insatiable economy's resource appropriation…..” (page45).

How then does Shiva portray ‘decentralized, low impact economies'?

She writes that the systems are ecologically sustainable because they actually promote a movement away from the current global industrialized economy towards a decentralized, low–impact economy and energy system governed by 'ecological democracy' (page 41), governed by the laws of Gaia and the universe – laws of physics, of evolution, laws of justice, where we remember we are 'earth citizens' (pages 43 and 44).

It is small farmers and other poor people who show us the way. They have never depended on the products of oil, and have learnt how to “live lightly"; they are people who define the good life not in terms of “shop till you drop" but as a life devoted to looking after the earth and communities of people, embedding the whole way of life into local ecosystems and local cultures, while reducing consumption (page 46).

We will return to energy production and use later.

Automobile–based versus animal–based economies, with a focus on India.

Shiva contrasts the developing Indian economy that is increasingly based on automobile use, and the traditional Indian economy based on the use of animals. Her symbols are the ‘sacred car' and the ‘sacred cow'.

The car is in effect treated as being sacred. Everything must adapt to the development of an automobile–based economy. In contrast, the traditional Indian economy was based on animal power.

We are given some basic facts about the growth of the automobile industry in India. The number of cars increased from 300,000 in 1951, to 5.4 million in 1981, 37 million in 1997 and 85 million in 2005. In the next few years, India is projected to become the fastest growing automobile manufacturer among the 20 top car manufacturing countries in the world. Even with the focus now in India on small low–cost cars, the projected increase in car production will cause an increase in petrol use from 6 million tons in 1997 to 25 million tons in 2015. Only by diverting large areas of land from food production to biofuel production can this requirement be met.

The development of the car–based economy has already resulted in a massive loss of land, much of it agricultural land, through mining of iron ore and bauxite to make steel and aluminium, construction of car factories and highways and infrastructure in urban areas, and providing increasing amounts of land for biofuel production. Many people have been uprooted, many settlements destroyed (page 67).

Often, land has been taken against the strongly expressed wishes of local communities, sometimes involving the use of violence. For example, the setting up of a car factory on 998 hectares of fertile land in Singur (in West Bengal) provoked conflict. Crops were destroyed, people attacked by the security forces, women molested, many people arrested, and there were hunger strikes, and farmers from twelve villages have pledged not to part with their land. The appropriation, of land from peasants has been facilitated by changes in the land acquisition act made under pressure from the World Bank and the Asian Development Bank.

The desire to facilitate automobile movement along highways and main roads in cities, has entailed restrictions on other forms of transport. Rickshaws and handcarts have been banned from many roads, yet man powered rickshaws account from between 25 and 80 per cent of vehicle trips in many cities and account for over 10 per cent of major city employment. And as elsewhere in the developing world, motorised transport has produced massive pollution leading to increased cancer and asthma rates and a massive increase in road deaths. Yet cars are owned by only a small minority of people; the market for cars is the 1.2 million middle–class people, out of 1.2 billion people, so the vast majority of Indians do not benefit directly from car use.

All this expansion of the car–based economy has and is being accelerated by major world car producing companies moving into India in search of cheap land and cheap labour, and India is increasingly gearing up for car export.

And the expansion has sometimes been accompanied by corruption and fraud. Thus the construction of the 160 km express way between Noida and Agra, was in effect sidelined by efforts to ensure one particular bidder for the contract won the bid and received the land. The project to construct an express way between Bangalore and Mysore requires 8,000 hectares of land. The government bought the land from farmers at below Market rate and gave the land to the developer at even lower rates.

The extension of the highway network and the gradual loss of community control of land increases government control across the country, and Shiva actually points to the example of Nazi Germany where, she writes, “highways were designed as means of centralized control, fascism and dictatorship, and not as routes to human freedom and democracy” (page 60).

Now for the ‘sacred cow' . The Cow brings many benefits to local communities, besides providing draught power. It provides milk and milk derived products. It provides fertilizer in the form of organic manure. It provides panchkavya (a fermented mixture of urine and other natural products) used for pest control. But the ‘sacred cow' is actually a symbol for much more than just cows. It is a symbol for a traditional Indian economy based on various domesticated animals.

The traditional Indian economy was based on animal draught power for transport of goods and people, and for ploughing. Animals are “a living energy alternative for mobility” (p. 73). Elephants have been used for moving people and goods for millennia. Camels are used as draft animals, drawing water from wells and extracting oil from oil seeds. Oxen, donkeys and horses are all used for transportation.

Shiva gives us some eye–catching quantitative data on the use of animals in the economy. Thus, on the small farms of India, animals plough 100 million hectares (page 76). Animal energy saves India six million tons of petroleum yearly. There are over 10 million animal drawn vehicles in the rural parts of India. The total value of animal output in India is 1.2 trillion rupees.

More generally, “in the third world, 2 billion people depend on animal energy, and 50 percent of the world's food supply depends on animal energy” (75).

A critique of biofuels.

Fuels from biomass are still the most important energy sources for the poor of the world. Energy for cooking comes from inedible biomass such as the stalks of millet plants, and pulses (edible seed producing leguminous plants), and trees planted for biomass production. On village commons, such biomass production, as part of a sustainable food production system, has been used for centuries.

In contrast, and globally, the promotion of industrial biofuel monocultures is destroying biodiversity, promoting centralized corporate land ownership taking land from the poor, reducing food producing land areas, and supporting the luxury consumption of the rich.

Biofuel production is resulting in the loss of vast areas of rainforest “the lungs, the heart, the liver of the planet” (p.82) (forests are needed for carbon dioxide sequestration, maintenance of biodiversity, etc.). In Brazil since January 2003, 70,000 sq. kilometres of rainforest have been cleared for biofuel production. Since 1990, Indonesia has destroyed 28 million hectares of rainforest for palm plantations.

The increased production of biofuels at the expense of growing food crops has the effect of raising food prices. In the USA for example, in 2007, the increase in ethanol production for biomass will account for more than half of the global increase in demand for corn.

Production of biofuels also threatens water resources. Shiva highlights China and India where there are plans to greatly expand biofuel production. But in many areas water is already scarce, and biofuel production could threaten river and groundwater supplies.

Shiva claims the production of industrial biofuels is not ‘green'. In the first place deforestation to provide land for biofuel crops is leading to increased carbon dioxide emissions. According to one source, destruction of Southeast Asian forests for palm oil production is contributing 8% of global carbon dioxide emissions.

And if the full emission costs of producing biofuels are taken into account, it has been claimed by D. Pimentel of Cornell University and T. Patzek of Berkeley University of California that it takes more fossil fuel input to produce biofuels than the resultant biofuels can generate.

Shiva gives an example from India of the effects of promoting biofuel production. There the growth of a poisonous shrub (Jatropha curcas from Central America, useful for making living fences), is being promoted for biodiesel fuel production as the seeds have a high content of oil, but Jatropha is not a food plant.

In the Chhattisgarh region, the government wants to plant J. curcas on tribal land, robbing the people of land on which they have grown rice for 40 years. And in Rajasthan, despite local opposition, villages are losing grazing lands for J. curcas production.

The Indian government intends to replace 20% of its diesel with biodiesel. There has been a call to use 11 million hectares of 'unused' or 'waste' land for J. curcas production. It is argued that J. curcas will provide villagers with a local energy source. But, says Shiva, setting up large–scale industrial plantations of this plant will actually ensure the oil will flow to cities, not to villagers.

Industrialized, global agriculture, and localized, biodiverse ecological agriculture, again with a focus on India.

Here Shiva gets to the heart of the matter. She contrasts two methods of food production, industrialized, global agriculture , and localized, biodiverse ecological agriculture (essentially small scale organic farming). I will refer to these systems as IGA and LBEA respectively. In her view, the former is in every way bad, the latter is in every way good. The chief points she makes can be summarised under the following headings – soil fertility, energy use, national and local control of agriculture.

Soil fertility.

In IGA fertility depends on an external source, namely nitrogen, phosphate and potassium in artificial (inorganic) fertilizers. In LBEA it depends upon an internal source, nutrients produced by the microorganisms in the soil.

However, artificial fertilizers emit nitrous oxide, a potent greenhouse gas, which destroys soil microorganisms that lie at the heart of natural soil fertility and blocks the soil capillaries by which nutrients and water are supplied to the plants. And high crop yields made possible by the use of massive inputs of artificial fertilizer and high yield crop varieties lead to depletion of soil micronutrients such as zinc that are not provided in the artificial fertilizers.

In LBEA, soil organisms maintain the soil structure, contribute to the biodegradation of dead plants and animals, and supply nitrogen to the plants through fixation of atmospheric nitrogen. Locally produced green manures and farmyard manure increase soil fertility. And Shiva reports that in one area in India, the soil of the Navdanya farm she had been working with, had 124% more organic matter than in what she describes as ‘chemical farms' (presumably in the same area).

Shiva also addresses the question of yields from the two types of farming. Yields per acre are generally high in IGA farming and are generally represented as far higher than in small scale, peasant farming. But Shiva points to good and increasing yields in LBEA farming. She gives details of the farming practices at the Navdanya farm. Here, instead of growing a single crop in a field, ‘mixtures' are grown – the classical organic farming method advocated by Sir Albert Howard in 1940. Seven, nine or twelve crops are grown in one field. Such farms perform much better both in terms of yield and capacity to survive difficult climate conditions (frost, drought, early rain or late rain, too little rain or two much rain) than IGA farms.

Energy use.

IGA is dependent on fossil fuels, and increasingly so. Inorganic fertilizers and pesticides are generally produced from fossil fuels, fuels that are also used to run the essential adjuncts of IGA, namely tractors and heavy agricultural machinery. There has been a major shift to highly processed and packaged foods involving yet further use of fossil fuels.

The globalization of food supplies (increased imports and exports), and the increase of major within–country movement of food to major distribution centres accomplished by the use of heavily fuel consuming heavy goods vehicles – and with fruit and vegetables these need to be refrigerated – has led to a massive increase in fossil fuel use and consequently greenhouse emissions.

Overall, IGA uses much more energy per hectare than LBEA. Shiva reports research that found the energy required to produce one kilo of rice in the USA is 80 times that needed in the Philippines, and to produce one kilo of corn is 33 times that used on a traditional farm in Mexico.

National and local control of agriculture.

Globalized trade, promoted by the World Bank and the World Trade Organisation, but also promoted by and controlled by big international companies like Monsanto and Cargill, compromises national and local control of food production, benefiting the rich countries of the north at the expense of poor countries of the south.

Global retail chains like Tesco and Sainsbury's have increasingly been getting their fruit and vegetables from Africa and India. So often scarce water supplies are being used to supply food to the rich industrialized countries and this trade, Shiva alleges contributes to drought and desertification (she comments that a 50 gm bag of salad in the UK required 50 litres of water in its production). India is being made to grow vegetables for Europe, but at the same time it imports vegetables. And it spends three times as much to buy raw vegetables abroad than it is earning from exporting them! India is the second biggest wheat producing country in the world, yet foreign companies were importing so much wheat from India that India was forced to import (pesticide–laden) wheat.

The move to large monocrop, cash crop cultivation for the export market also meant that local peasant farmers were dispossessed of their land. And the import of fertilizers to support this industry, with the rise in fuel prices, meant that the Indian government was subsidising fertilizer prices to farmers, recovering the money through taxes, while the big international agribusinesses made vast profits.

Shiva here takes a swipe at what she calls ‘pseudo–organic farming' in developing countries: large–scale corporate farming which uses methods entitling the use of the organic label but which does not satisfy a key feature of what to Shiva is the genuine organic farming – small scale production for local communities who can then see, understand and appreciate the organic farming method; also it destroys small farms to create the large industrial farms. Shiva is also not in favour of the use of genetic engineering. She points out that traditional farming has produced crop varieties that may be used to combat climate change effects like increased drought, or increasing rainfall in other areas. She claims: “Genetic engineering does not create the traits for drought, flood, and salt tolerance; it merely allows the transfer of traits across species” (page 120). All genetic engineering does is to allow big international companies like Monsanto and Cargill to secure greater control of global agriculture and make massive profits, “destroying biodiversity, local food systems, and food cultures” on the way (page 121).

A philosophical-religious underpinning.

Shiva's Conclusion chapter (“unleashing Shakti: our power to transform”), provides a philosophical–religious background to her arguments. What is Shakti? Shiva writes: “Energy is Shakti – the primordial power of creation, the self–organizing, self generative creative force of the universe in feminine form” (page 136).

The generative force of Shakti gives us the sun's energy, creates climate, and is “an all–pervasive element of life”. This religious or philosophical view is underpinned for Shiva by an ancient Indian philosophical text (the Devi Bhagwat Puran ), the writings of the 12th century abbess Sister Hildegard of Bingen, and the Jain monk Satish Kumar. For Shiva, all the discussions on industrial processes, economic growth and food production have this mystical underpinning.

My assessment of the book.

It must be very satisfying to believe in Shakti; but leaving such belief aside, the evidence that Shiva produces to support her claims about the inadequacies of the policies of the industrialized world is compelling, as is her evidence about the value of localised communities practising organic farming in rural areas of India and other developing countries. However, I do have one worry about the farming practices of such rural communities. As she notes (page 77), one source of energy for cooking is the inedible stalks of crops; I add also cow dung. Yet adopting this practice, instead of returning crop residues to the soil, is one reason for the ongoing reduction of soil fertility in many areas.

Organic farming in small communities may be the best system of food production for rural areas in developing countries. But its application on a wider basis is, I think, limited (is Shiva advocating this?). The fact is that a little over half of the global human population now lives in urban areas, mostly densely populated. Many people live in megacities (population 10 million or more). Now people in cities could become more involved in a collaborative effort to use their gardens for food production and establish networks of supply from farms in the countryside, and I made a case some years ago that it would be possible to make cities in the UK self-sufficient for vegetable production (see footnote 1). However, most of the human population of the planet could clearly not become part of the sort of communities that Shiva promotes.

And if organic farming as generally understood by that term was adopted throughout the world, not only in small communities, requiring a massive transformation of farming systems in industrialized countries - could it feed the whole global population? Well Lawrence Woodward, Director of Elm Farm Research Centre, made a case a few years ago for the argument that organic farming could feed the world population provided certain other changes were made such as creating favourable fiscal environments for ensuring food security and changing diets to diets with a predominantly vegetable content (footnote 2). However, these are big provisos. And many agricultural experts would not agree with this sanguine view of the potential of organic farming.

For me however, the chief defect in Shiva's analysis of the global situation is that she completely neglects the importance of human population growth as a cause of environmental problems.

Thus in her introduction, she lists the three crises she thinks threaten the survival of mankind:
climate warming, the end of cheap oil (energy supply) and food supply. We believe there is a fourth crisis – the continued massive growth of the human population, which is an underlying cause of the three crises she mentions.

The unreasonableness of ignoring population growth becomes immediately clearer when she goes on to state that for the survival of the poor of the world, the food crisis is the most immediate threat. And she states what she regards as the two most important underlying causes of this crisis – industrialization of agriculture and 'uprooting' peasants from the land, and loss of food security through globalisation. Clearly she should have here specified human population growth as an underlying cause, arguably the most significant of underlying causes. Increase in population has been the main driver of all the efforts globally to increase food production and it is now clear that it is becoming more and more difficult to cope with continued population increase.

Shiva makes it very plain that she approaches her work from the 'perspective' of people in the 'Global South'. This immediately raises the question – will this lead her to lay disproportionate blame on the industrialized North for the present and future ills of the planet, especially the ills of the South. Her neglect of human population growth could be a case in point. Between 2007 and 2050 the global population is projected by the United Nations to grow by an amount roughly equivalent both to the combined present day populations of China and India, and the size of the whole world population as it was in 1950. Most of this future population growth will take place in developing countries most of which still have fertility levels higher, often much higher than replacement level (China being a significant exception) – contrast industrialized countries almost all of which have fertility rates below replacement level, mostly well below that level. Could this be why Shiva is silent about human population growth?

In my view Shiva over–stresses the role of the industrialized north for causing the global problems she details by underplaying the complicity of developing countries. It is of course true that the industrial world has forced through many measures in developing countries that she objects to. But often, developing countries seem to have been eager to accept industrialized world remedies. For example, in her own country India, where she alleges that globalization is pushing India to become a hub for the production of motor vehicles, she also writes that this development was welcomed, indeed promoted by some Indian leaders.

Finally Shiva's book suffers from the bad habit of mixing topics, sometimes breaking the thread of her argument. This fault no doubt arose from her commendable wish to show that all problems and all solutions are interrelated. But as I read, and worse still, when I attempted to review this book, I found myself increasingly living in a state of mental indigestion, not helped when she occasionally adopts a rhetorical but imprecise style. The lack of any diagrams to show causal relationships adds to the problem.

Footnote 1. In Barker, J.F. (1998). “England AD 2,200. How would you like it to be?”. Gaia Watch.

Footnote 2 . The essay by Lawrence Woodward accessed from the Analysis section of our Comment and Analysis page.


Copyright ©John Barker.

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Review by Peter Salonius of the book by William Stanton (2003) “The Rapid Growth of Human Populations 1750–2000. Histories, Consequences, Issues Nation by nation.”. Multi-Science Publishing Company Ltd.

William Stanton states that 'All human history is of populations expanding when resources are available and shrinking when they are not', and he predicts that 'population reduction will begin as soon as foreign aid dries up' and when basic 'carrying capacity will become critical'. If it is necessary to read the history of collective human reproductive mistakes in order not to repeat them, or to avoid continuing to make them, then this is the book that should be read by all policy makers who have anything to do with famine relief, foreign aid, fertility control education as well as immigration/greenhouse gas emission. It offers a graphical record of recent population growth as well as a brief verbal summary of the political history for every nation.

Stanton's panoramic history takes us back to the transition from hunter–gathering to agriculture about 10,000 years ago when he supposes that world population may have been double the 2 million of 100,000 years ago. The Agricultural and Industrial revolutions in the mid 18th century, and the Green revolution in the mid 20th century increased the ability of society to feed greater and greater numbers. He points out that before 1750 most of the world's half billion people lived on the edge of starvation, confronted with repeated famines, and 250 years later almost five times as many survive in similar conditions. The increased food produced by the Genetic revolution in the 21st century is expected to be similarly unsuccessful in raising living standards, because the response of our species has been to produce more babies to meet the increased carrying capacity that these revolutions have facilitated. 'Darwinian' reality, with only the fittest surviving the scarcity that results when births exceed deaths, has been suspended for the last 250 years. Until the mid 18th century there was a very slowly rising population ceiling as deaths approximately equalled births.

With population growth currently exceeding 80 million per year, Stanton says that 'most of the world's people are entirely unaware that they are living in an anomalous [period of ever increasing food production], which, after 250 years is approaching its end.'

Historical carrying capacity, absent the temporary increase made possible by exhaustible fossil fuels, is dealt with early in the book using England as an example; from 300 BC, until coal and then oil made vastly more food production possible starting around 1750, the population approached five million several times but it repeatedly collapsed to much lower levels due to poor crop yields, tribal warfare and disease. The “Death Control (DC)” in the intervening two centuries, that has produced a ten fold population increase, has been dependent upon the increased agricultural carrying capacity and improved health care that are supported by finite exogenous geological energy stores. Stanton and a growing number of others foresee future energy scarcity orchestrating a population collapse, back to historically, solar–energy supported levels, during the next 100 years. Estimates of human numbers after the collapse vary from the 600 million that solar energy supported in 1750, to perhaps 4 billion, depending on whether global energy depletion or local factors such as water shortage, desertification, sea level rise, climate change or the overcrowding and land hunger that produce 'Violent Cutback Level (VCL)' drive the collapse. Stanton appears to define the population densities (persons per square kilometre) that result in 'VCL' by hindsight according to when and where tribal conflict, genocide and ethnic cleansing have taken place.

Although population percentage growth rates are decreasing worldwide, Stanton drums home the fact that population numbers continue their inexorable and uninterrupted exponential increase due to the ever larger numbers these percentages are based upon. Relief from population pressure is provided by emigration from areas where numbers grow faster than their economies, to areas where the economy is still growing faster than the population, and by longstanding foreign aid programs and famine relief that mask the fact that the land will no longer feed the increased number of mouths. The continuing acceptance of massive numbers of immigrants and provision of food aid, by countries that are still able to produce agricultural surpluses, are seen to allow inappropriate fertility patterns to be irresponsibly maintained.

Stanton is very critical of the willingness of aid agencies to take the easier course of 'saving lives' with food aid that artificially maintains reproductive strength as human populations continue to further overshoot the carrying capacity of their lands, while most of these aid providers refuse to address the more difficult issue of assistance with the birth control programs that many women are clamouring for in recipient countries.

The book illuminates the concept of competitive breeding, wherein certain ethnic groups openly admit that they have a policy of maintaining irresponsibly high birth rates ('We will beat you in the beds'), designed to produce long-term political and militarily dominance, at great cost to the natural ecosystems that must support them long after current conflicts are forgotten.

The author designates the last 250 years as an historically unprecedented, one–time phenomenon with 'Weak Restraints On Growth (WROG)' as escalating human numbers rapidly draw down the Earth's resources (especially non–renewable energy). He attributes much of the reluctance to deal with the 'delicate subject' of population control to the now obviously failed 'Demographic Transition Theory' of Adolphe Landry (1934), that assumed increased prosperity and food supplies would result in people having fewer children. This idea 'has persuaded decision takers and their advisors that population growth is not a serious problem because financial aid will sort it out'. If Stanton had written the book in 1960 and policy makers had taken remedial action, there might be several billion less people contributing to the global carrying capacity overshoot than there are today. He suggests that donor nations must finally realize that population control must precede attempts at poverty reduction because the other way around does not raise living standards.

Stanton sees multiculturalism and massive immigration policies being feasible only when conflict to control resources is unnecessary, in countries whose populations still are growing slower than their economies. He anticipates violent 'religious', 'ethnic' and 'class' conflict to control shrinking resources as the legacy of such policies when the temporary (200 year long) 'Petroleum Interval' begins to wind down.

At the end of the book, Stanton speculates that 'political correctness', 'civilized standards', current ideas about 'human rights', and the concept of 'the sanctity of human life' will disintegrate in the face of resource conflicts and massive movements of refugees from lands whose carrying capacity has been reduced by combinations of soil depletion/erosion, desertification, sea level rise and the lack of continued access to non renewable energy stores. Among grim alternatives, he foresees a return to 'quick and inexpensive corporal punishment for lesser crimes' (corporal punishment being defined as whipping, the death penalty and imprisonment), the general encouragement and legalization of 'euthanasia, abortion, and infanticide for handicapped babies' as well as the enforcement of severe restrictions on family size.

Stanton hopefully speculates, as have others, that the population collapse that is expected during the 21st century will produce a smaller human society that will have 'the wit' to restrain its numbers so as to allow 'a sustainable high quality of life', at a level that is in balance with the Earth's long–term carrying capacity, and a level that may even allow some repair of an Earth that has been considerably damaged by the open–ended expansionism of the last 250 years.

Reprinted from Futures, vol 38 no. 5, Salonius, P. “The Rapid Growth of Human Populations 1750–2000: Histories, Consequences, Issues” pp 630-632, copyright 2006 with permission from Elsevier.
Futures. We thank Peter Salonius and Elsevier for agreeing to us posting this review on our website.

You may purchase this book at Amazon


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The following review by Albert A. Bartlett, Professor Emeritus of Physics at the University of Colorado at Boulder, was published in The Physics Teacher, December 2006, volume 44, pages 623–624. The Physics Teacher may be accessed on line at link.
We thank Professor Bartlett for agreeing to us putting his review up on our web site, and the American Institute of Physics for copyright permission.

Energy's Future Beyond Carbon and the Silent Lie

The September 2006 issue of Scientific American (SA) is a “Special Issue” devoted to “Energy's Future Beyond Carbon” with the subtitle “How to Power the Economy and Still Fight Global Warming”. As I read the issue I thought of Captain Renault, the Chief of Police in the movie “Casablanca” who says to an assistant, “Major Strasser has been shot. Round up the usual suspects”. The implication of the Chief's order is clear. Never mind finding the culprit, just “round up the usual suspects”.

The main body of this special issue consists of nine articles relating to global warming, each dealing with one or more of the usual suspects. These are summarized in the first article, “A Climate Repair Manual”. There we read that global warming is a major problem: “Preventing the transformation of the earth's atmosphere from greenhouse to unconstrained hothouse represents arguably the most imposing scientific and technical challenge that humanity has ever faced. Climate change compels a massive restructuring of the world's energy economy. The slim hope for keeping atmospheric carbon below 500 ppm hinges on aggressive programs of energy efficiency instituted by national governments”. The culprit is world population growth, but SA is just rounding up the usual suspects.

Some fraction of the observed global warming most certainly is caused by the release of greenhouse gases from the burning of fossil fuels. As the size of the world population increases, the rate of burning of fossil fuels increases and this can be expected to increase the rate of rise of global average temperatures. The authors of these nine articles have to know that the size of the global population is a major factor in determining the rate of release of greenhouse gases. Yet in a special issue devoted to reducing global warming, SA almost completely ignores population size and growth and instead “rounds up the usual suspects”— things we can do to reduce the human contributions to global warming such as the increased use of nuclear power and improving efficiency.

The special issue contains no serious evaluation of the problems of peak production of global oil, which could happen any year now.(1, 2) There is even a hint of denial: “Even if oil production peaks soon — a debatable contention given Canada's oil sands ” (emphasis added).

When one looks at the facts, one can see that production of gasoline from the oil sands won't have much effect on the peaking of world oil production. There is no serious discussion of the net energy in the production from oil sands, or in the production of ethanol from corn. It is just noted that we will have to be more efficient in these endeavors.

Growth remains sacred. “But holding CO2 emissions in 2056 to their present rate, without choking off economic growth, is a desirable outcome within our grasp”. To meet the growing global demand for energy, “thousands of new power plants must be built”. “If the fleet of nuclear power plants were to expand by a factor of five by 2056, displacing conventional coal plants”, what will we do after 2056? None of the authors expresses any recognition of Eric Sevareid's law, “The chief cause of problems is solutions”.(3) Example: Nuclear power is a solution to the problem of CO2 emissions from coal burning, but nuclear power comes with its own new problems. There is a lonely isolated touch of reality in the opening sentence of the article on renewable energy: “No plan to substantially reduce greenhouse gas emissions can succeed through increases in energy efficiency alone”. The reason behind this reality is that continuing population growth, even at the level of approximately 1% per year, will likely overwhelm the annual savings that can be achieved nationally or globally through improved efficiencies.

The article on hydrogen notes, “it could be decades before it [hydrogen] starts to reduce greenhouse gas emissions and oil use on a global scale”. We don't have decades.

There is blithe talk about the billions and trillions of dollars that it will cost to rebuild our energy infrastructure to enable the deployment of several of the “usual suspects”. There is no serious evaluation of the impact of such costs on people and on economies. For instance, it costs about $1.50 a watt to purchase a new coal-fired electric generating plant and since utilities budget some thing like 1000 watts of generating capacity per person, every new person added to the service area of a utility costs the rate payers about $1500. So every time the population of a utility's service area grows by one percent, every person in the service area has to pay approximately one percent of $1500, or $15, just to purchase new hardware for the generation of electricity to meet the needs of new people added to the service area.

The last article, “Plan B for Energy”, is prefaced with a futuristic drawing with the caption “Late 21st Century energy sources might include nuclear fusion reactors, hydrogen generated from ponds of genetically engineered microbes, high altitude wind farms [this is a new suspect], orbiting solar arrays, and wind and tidal generators, all linked to a worldwide superconducting grid”. The large electric distribution grids that span continents are enormously complex and they have the unpleasant habit of failing in massive and spectacular ways. Even more frightening is the fact that these enormous networks will be managed by people, and people will fail. I hope the future does not work out as it is portrayed in Scientific American and I don't think it will. A society that is totally dependent on high tech for the functioning of every aspect of the lives of its people is vulnerable to disruption by acts of God and acts of people. The complexities of our present infrastructure predictably lead to unpredictable failures. More complex infrastructures anticipated for the future will probably experience larger unpredictable failures.

In a short essay before the main energy articles (“Lower Fertility: A Wise Investment” by Jeffrey Sachs,(4)), there is a brief mention of population. This does address population growth but in a way I found contradictory and objectionable. “Rapid population growth is not the main driver today of these [environmental] threats”. Attention should be given to “high and rising rates of resource use per person rather than to the rise in the sheer number of people”. The world's rate of consumption of fossil fuels is the product of the population size and the average per capita annual consumption. Both have to be reduced. A few sentences later Sachs writes, “Yet the continued rapid population growth in many poor countries will markedly exacerbate the environmental stresses”. So population growth is not a problem and then is a problem. But shifting the blame to the people of poor countries is the “them, not us” response that is so often encountered when population problems are discussed.(5) Sachs then presents the arguments for working to lower the fertility rates of people in “poor countries”, pointing out our funding programs to help with this would be “among the smartest investments that the rich countries could make for their own future well–being”. The idea is good. The reason given is selfish and destructive. He seems to be saying that if we reduce “their” numbers, it will be a good investment for us because there will be more resources and better lives for us. If we want to help poor people, we will be helping them increase their per capita rate of resource consumption, which, for the foreseeable future, will increase the rate of global production of greenhouse gases. Only by reducing the size of the world population can we hope to be able to give significant help to poor people. Only by reducing the sizes of populations can we have a reduction in the overall global rate of consumption of fossil fuels and the consequent reduction in the rate of production of greenhouse gases. We must lead by example by addressing overpopulation in the United States.

Scientific American has rounded up the usual suspects but has ignored the perpetrator of the crime. The editors and writers at Scientific American know that population growth is the underlying source of the problems, but it is politically incorrect to state this obvious fact. Mark Twain wrote that if one has information that would help others, but does not share that information, then one is telling a “Silent Lie”.( 6 ) Because it does not address population size and growth as the main underlying cause of global warming, this issue of Scientific American is a serious “silent lie”.( 7 )


1. Kenneth S. Defeyes, Hubbert's Peak (Princeton University Press, 2001).

2. A.A. Bartlett, “An analysis of U.S. and world oil production patterns using Hubbert–style curves”, Math. Geology 32 , 1–17 (Jan. 2000).

3. E. Sevareid, “CBS News” (Dec. 29, 1970), quoted in T.L. Martin , Malice in Blunderland (McGraw–Hill Book Co., New York, 1973).

4. Jeffrey Sachs, Director of the Earth Institute at Columbia University and of the U.N. Millennium Project.

5. A.A. Bartlett, “Malthus marginalized”, The Social Contract 8 (3), 239–251 (Spring 1998).

6. Mark Twain, The Man That Corrupted Hadleyburg and other Short Works (Prometheus Books, Amherst, NY, 2002), p. 159.

7. A.A. Bartlett, “Thoughts on long–term energy supplies: Scientists and the silent lie”, Phys. Today 57, 53–55 (July 2004). See letters and responses, Phys. Today 54, 12–18 (Nov. 2004) and 58, 12–17 (April 2005).


Albert A. Bartlett,

Department of Physics University of Colorado at Boulder Boulder, CO 80309–0390.

Copyright 2006, American Association of Physics Teachers. This article may be downloaded for personal use only. Any other use requires the permission of the author and the American Association of Physics Teachers.


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Lovelock, J. (2003). “The revenge of Gaia. Why the earth is fighting back - and how we can still save humanity”. Allen Lane.
ISBN-13:978-0-713-99914-3. ISBN-10:0-713-99914-4.


Gaia, that self-regulating system consisting of the atmosphere, living things and the ecosystems that contain them, the oceans and the underlying rocks, is in danger. Such is the warning given us by James Lovelock in his new book “The revenge of Gaia”.

The regulation works through what are called 'feedback' mechanisms, and in the glossary at the end of the book Lovelock gives an explanatory example of such mechanisms:

If the car we are driving deviates from the intended path, we adjust the wheels to try to cancel the deviation. The power steering amplifies our action ( negative feedback ). But if the steering mechanism was faulty and it increased the car's deviation from the chosen path, the initial error would be amplified ( positive feedback ).

The earth remains a suitable place for man and other living organisms through negative feedback. Unfortunately, the balance of Gaia is now being disturbed by positive feedback mechanisms: One example given by Lovelock concerns the melting of snow on land. This snow reflects almost all the sunlight that reaches it and thus helps to keep the world cool. But as the snow melts at the edges, the dark ground that is then at the surface absorbs much of the sunlight and gets warmer. The increase in ground warmth accelerates further snow melting.

Lovelock says that nearly all the processes that affect the climate of the earth are now in positive feedback, and he gives six examples of these processes. Together, these processes are likely to push Gaia quite suddenly from its present equilibrium to an equilibrium at a much hotter state, and this change beyond what Lovelock calls a 'tipping point' may occur soon.

If this happens - perhaps by the end of the present century - the climate of the world could then “be described as Hell: so hot, so deadly that only a handful of the teeming billions now alive will survive” (page 147). And later he writes about this possibility “.. a massive decline in population, leaving an impoverished few survivors in a torrid society ruled by warlords on a hostile and disabled planet” (page 151).

Strong stuff. But this is not the language of some columnist in a popular newspaper. It is written by a scientist who for many years has explored the properties of Gaia. A member of the Royal Society, Lovelock has, according to his own web site, produced about 200 scientific papers spread almost equally among topics in medicine, biology, instrument science and geophysiology.

It was Lovelock who first proposed what came to be called the Gaia hypothesis of planetary regulation, and he traces the development of the hypothesis. Initially he had thought that it was living organisms alone that regulated the climate and the chemistry of the atmosphere and "in their own interest" (page 22). Evolutionary biologists were sceptical of this idea, which, they argued, was incompatible with the concept of Darwinian evolution ".. since the organism was the unit of selection, not the biosphere" (page 23) and "all life is urged by its selfish genes to reproduce, and if the only constraints are competition and predation, the result is a chaotic fluctuation of populations" (page 26). Lovelock accepted there was an incompatibility and consequently his hypothesis needed to be modified (page 23).

Lovelock came round to the idea that it was living organisms and the material environment that together evolved as a self-regulating system (page 23). To test his hypothesis Lovelock developed his now famous Daisyworld computer model. Here dark and light daisies compete on a planet where the sun, as it grows older, gets hotter. Initially dark daisies flourished since they absorb sunlight, and this kept them and the whole planet warm. As the sun heated up, the light daisies gradually displaced the dark daisies because they reflected the sunlight and so were cooler than the dark daises, and they cooled the planet. The important point is that during this long process of competition for space, the planet always stayed near the ideal temperature for life. Eventually however, the sun became so hot that even the light daisies could not survive and the planet became lifeless.

Lovelock went on to construct and run models richer in species and including animals as well as plants. These models produced systems just as stable and self-regulating as the Daisyworld model. And gradually Lovelock's hypothesis gained wide acceptance. At the same time, in relation to the views of some evolutionary biologists, he argues that the evolution of ecosystems is not entirely comprehensible through the concept of the 'selfish gene'. When an ecosystem is disturbed by excessive physical conditions like drought, it can evolve simply by the selection of existing species - tolerant species are selected from the array of species and may come to dominate the ecosystem. Then "the fine tuning of genetic evolution completes the process of adaptation". (page 27).

Lovelock discusses in detail the regulatory mechanism of Gaia. He emphasizes that the stability of the system depends upon environmental constraints imposed by global properties such as atmospheric and oceanic composition. He asks how do these constraints work? And he answers "they depend upon the tolerances of the organisms themselves. All life forms have a lower, an upper and an optimum temperature for growth, and the same is true for acidity, salinity and the abundance of oxygen in air and water. Consequently, organisms have to live within the bounds of these properties of the environment" (page 27).

Lovelock gives examples to illustrate the way constraints work, and here is one that concerns the oceans: The sun warms the surface layer, providing the warmth that the primary producer organisms require. As this water warms, it expands and becomes lighter than the waters beneath. This 30 to 100 metre surface layer is stable - no currents between it and the deeper layers of water. So in spring, the primary producers soon use up the nutrients that are in the surface layer. Their dead bodies sink down into deeper layers, so those dead bodies do not replenish nutrients in the surface layer. Soon the primary producers starve. This is why the water in the tropics is so clear and blue. Only when there are fierce storms does mixing between layers occur. Oases occur on some continent edges where there is upwelling of water from deep layers.

I have mentioned the use of computer modelling to explore the regulatory mechanism of Gaia, and Lovelock tells us how this modelling has informed us about the limits beyond which the stability of Gaia is compromised: Gaia can withstand variations in the total amount of life on earth, but there is a critical mass below which Gaia becomes unstable. Gaia will tolerate some changes in heat input from the sun. It will also tolerate varying inputs of carbon dioxide. But modelling suggests that when carbon dioxide levels rise to 500 parts per million (ppm), regulation begins to fail, and there is a "sudden upward jump in temperature" (page32). And Lovelock says many scientists now agree that a rise to 500 ppm, "which is now almost inevitable, will be accompanied by profound climate change" (page 48). Lovelock also notes that in the last glacial period carbon dioxide levels fell to 180 ppm but rose to 280 ppm after the ice age ended; but now, as a consequence of our polluting activities it has risen to 380 ppm. And he thinks it is likely to continue to rise to 500 ppm or more (page 58), a level beyond the stability threshold.

Finally, Lovelock points out that the regulatory mechanism of Gaia is extremely complicated, and by no means fully understood. There is something elusive about Gaia, and the whole regulatory mechanism is more than the sum of the parts (page 37).

All this is fascinating. But I wish that Lovelock had given us more quantitative information on some of the component parts of the regulatory mechanism. For example, carbon sequestration by tropical forests and the oceans is vital to the regulatory mechanism of Gaia and it would have been nice to learn about the quantities sequestered and the importance of these sequestrations. And it would have helped readers to achieve an overall understanding of what we know about the regulation of Gaia if Lovelock had attempted to produce a diagram showing the interrelationships of the various factors involved in this regulation.

Lovelock goes on to describe the 'life history' of Gaia, from when life on earth began three to four billion years ago, to the present. Since the beginning of life there have been massive changes in the composition of the atmosphere. Early on, the atmosphere would have changed from one dominated by carbon dioxide to one dominated by methane produced by organisms called methanogens. Later came oxygen, and its subsequent massive increase was caused by the newly evolved photosynthetic organisms. The appearance of free oxygen was a very important event:
"It drove the evolution of more complex living cells, the eukaryotes and eventually the huge assemblies of living cells that make up plants and animals. Not least, it allowed the Earth to retain its oceans by acting as a barrier against the escape of hydrogen to space".

Changes in the sun have taken place alongside changes in the Earth's atmosphere. At the beginning of Gaia, the sun was not as hot as it is now. In fact it was "too cool for comfort". But it gradually got hotter, and now it is too hot. Regulation has succeeded up to the present, but we are now at crisis point. And even ignoring man's intervention with Gaia, "in about one billion years, in fact long before the sun's life ends, Gaia will die from overheating". On the cosmological time scale, Gaia "is old and has not very long to live".

Turning now to our present problem of global warming, the immediate cause is the increased production of carbon dioxide through fossil fuel combustion. But this increased production is occurring at the same time that forests which play such a major role in regulating climate, are being destroyed, and other ecosystems vital to Gaia are being debilitated. And underlying all these changes is the growth of the world human population - "the root of our problems with the environment comes from a lack of constraint on the growth of population" (page 140, my bold text). Indeed again and again Lovelock draws attention directly or by implication to the significance of population growth and the present large size of the human population for the regulation of Gaia (pages 6, 79, 91, 121, 140, 150).

He links this large population size with the high level of human consumption and waste production "as always, we come back to the unavoidable fact that there are far too many of us living as we do now" (page 72 - see also pages, 109, 115 and 141; and page 86 in relation to necessary food production for so large a population: "we have already taken more than half of the productive land to grow food for ourselves"; see also pages 67 and 155). And Lovelock thinks we should "aim at a stabilized population of about half to one billion" (page 141), a small fraction of the present day population size.

Lovelock clearly sees population size as a vital consideration when he comes to consider the different energy sources that could be used in future to ensure we reduce greenhouse gas emissions, a subject to which he devotes his longest chapter. This is implicit in his discussion of Bio fuels:

"We have already taken more than half of the productive land to grow food and raw materials for ourselves. How can we expect Gaia to manage the earth if we try to take the rest of the land for fuel production?" (page 67 - see also pages 85 and 86).

In this energy source chapter, Lovelock says we need to develop a portfolio of energy sources. This would include nuclear energy, renewables, and "burning fossil fuel under conditions where the carbon dioxide effluent is safely sequestered..". Other methods of energy production would also have a place in the portfolio such as wave and tidal energy (he supports the idea of a Severn Barrage), and wind power (especially when we learn how to store the energy).

However, Lovelock thinks nuclear power should be the main energy source used in the future. And his chief reason for saying this is that nuclear reactions are much more energetic than ordinary chemical reactions. The chemical reaction of burning carbon in oxygen can produce up to nine kilowatt hours per kilogram. Nuclear reactions produce million times as much energy. "This means that the amounts of nuclear fuel needed to supply our energy demands are tiny compared with Gaia's normal mass transactions, and so is the quantity of waste produced".

Lovelock draws attention (pages 87 and 88) to an important difference between the two types of nuclear power - nuclear fission and nuclear fusion . The former is 'dirty', leaving behind a massive legacy of radioactive waste. The latter produces no radioactivity except a very small amount in the walls of the containers used in the manufacture of the energy (page 90). However, it will be a long time before research provides us with commercially available fusion reactors. For the time being, we need to use fission reactors despite fears over radioactivity:
"I am not recommending nuclear fission energy as the long-term panacea for our ailing planet or as the answer to all our problems. I see it as the only effective medicine we have now" (Page 11). But he seems to thinks that in the long run, nuclear fusion should become our main source of energy.

What else does Lovelock think needs to be done now to mitigate the adverse changes taking place in Gaia, besides developing a suitable energy strategy? Well in the first chapter we read:

"We need most of all to renew that love and empathy for nature that we lost when we began our love affair with city life" (page 8). This is an aspect of a necessary change of attitude, a subject Lovelock takes up again in chapter 6.

There he introduces this change in attitude through an account of the use of chemicals, - pesticides, herbicides and fertilizers - in disease control and agriculture. On the way he criticises 'affluent radicals', 'environmentalism' and 'greens'. He notes that the use of chemicals has produced benefits as well as harm. Thus DDT, in its original role of combating insect-borne disease, saved millions of lives yearly, until it was banned "through fear of cancer in the first world" (page 112), a ban "driven by affluent radicals in the first world" (page 108). DDT, he claims, only became an environmental threat when agribusiness began to use it on a large scale.

Lovelock describes the changes that have taken place in the English countryside since the Second World War as farming practice changed - the loss of small meadows and hedgerows, the increased use of chemicals, the adoption of slurry farming, the decline of wildlife, the decline of rural communities. But he seems to think chemicals do have a legitimate place in agriculture. And he argues that the increasing focus of environmentalists, scientists, the media, and discussion round dinner tables on harm to humans from chemicals (fear of carcinogens, etc.), and the consequent obsession with organic farming led to 'Greens' "drifting dangerously into an obsession with personal human problems" (page 112).

And many Greens promoted the final solution to the problems of rural regions - making these regions the place for industrial-scale renewable energy and wind farms including "growing cash crops for bio fuels to keep the city lights glowing and the urban transport running" (page 111). At the same time, It may be only human to be concerned about "the welfare of fancy birds and cuddly animals living in Rousseau-style forests far away" that do not do a great deal for Gaia - and he immediately links this with 'environmentalism' - 'environmentalism' has largely ignored the organisms that do most of the hard work that keeps Gaia going - micro organisms, slime moulds, fungi, worms and trees (page 111).

Furthermore, the 'silent spring' of Rachel Carson was not caused simply by the poisoning of birds by pesticides. The birds died because they no longer had adequate space in the modern intensively farmed world. "There are so many humans now aiming for a first-world lifestyle that we are displacing our partners on the planet, the other forms of life. We have to realize that cutting back emissions of greenhouse gases is only part of what we have to do; we have also to stop using the land surface as if it was ours alone. It is not: it belongs to the community of ecosystems that serve all life by regulating the climate and chemical composition of the Earth" (page 109).

So we come to the necessary change in attitude. Lovelock focuses here on 'Greens', but it is clear he has mankind in general in view:
"..we ask the urban greens to think again and see that their primary obligation is to the living earth. Humankind comes second" (page 121). Then on page 134 "I have to stress that the well being of Gaia must always come before that of ourselves: we cannot exist without Gaia" And Lovelock refers to this same imperative on page 148:
"We are part of the Gaian family and valued as such, but until we stop acting as if human welfare was all that mattered, and was the excuse for our bad behaviour, all talk of further development of any kind is unacceptable".

So we need to change our focus from human problems, to the needs of Gaia.

Lovelock returns to the theme of what we need to do to avoids catastrophe in his last chapter. He views the situation as analogous to that faced by Napoleon in Moscow "..we have too many mouths to feed and resources that diminish daily while we make up our minds". So "we need the people of the world to sense the real and present danger so that they will spontaneously mobilize and unstintingly bring about an orderly and sustainable withdrawal to a world where we try to live in harmony with Gaia" (page 150).

Narrowing his focus to Europe , Lovelock asks the question:
"..what should a sensible European government be doing now?". And he answers his own question ".. prepare for the worst and assume that we have already passed the threshold" (page 152).

We need to secure safe sources of energy. And " We may need restrictions, rationing and the call to service that were familiar in wartime and in addition suffer for a while a loss of freedom " (my bold text). We need to set up a small group of strategists as we had during the last war. And perhaps "we should listen to the deep ecologists and let them be our guide": "like the holy men and women who make their whole lives a testament to their faith, the deep ecologists try to live as a Gaian example for us all to follow" (page 154). And finally, we need to write a book containing a summary of our knowledge, "a guidebook for our survivors to help them rebuild civilization without repeating too many of our mistakes" (page 156) .

Well the present book can certainly contribute, through its penetrating analysis of Gaia, to explaining both the mistakes man has made in the past, and the basic biophysical processes which maintain the planet in a fit state for man to inhabit. Although the emphasis is on physical processes, Lovelock does not demand of his readers a university level understanding of physics and chemistry. And there are some excellent colour photographs that illuminate important aspects of the changes taking place on Earth.

And Lovelock throws in some startling facts that help to maintain our interest. Consider for example, the annual production of carbon dioxide over the whole globe. This is 27,000 million tons. Freezing this into solid carbon dioxide at -80 degrees C would make a mountain that was one mile high and twelve miles in circumference (page 73). In contrast (page 91), the same quantity of energy produced by nuclear fission would produce carbon dioxide which would only occupy a sixteen metre cube, two million times less waste!

This is a thought provoking book, first, because it forces us to think more deeply about the seriousness of the global situation, secondly because it challenges some widely held opinions, and thirdly because it makes us realize how we have an "unfortunate tendency to do harm while trying to do good" (page 116). He provides the example of our reactions to the harmful effects of acid rain. We all know about acid rain and its effects on forests, lakes and rivers and that this is caused by acids of sulphur. And Brussels is bringing in legislation to curb these emissions.

However, it has recently been confirmed that the "all-pervasive European atmospheric haze that blights the summer skies and reduces visibility... is a sulphate aerosol". This haze reflects sunlight back into space "and keeps those of us beneath it several degrees cooler than we might otherwise be" (page 119).

Lovelock asks us to consider how much worse things would have been back in the summer of 2003 with its intense heat, if this aerosol had not been present in the atmosphere - and he adds how much worse it will be for us when the European legislation really starts to work!

Some readers will probably disagree with Lovelock' assessment of the relative merits of different energy sources, especially of course his espousal of the nuclear solution. For me, I was disappointed that Lovelock did not assign greater significance to drawing heat energy out of the mantle of the earth. He does briefly mention this (page 68), commenting "there are few places where it is freely available". But could not techniques be developed to make a much greater use of this source of energy? We are after all sitting on an immense quantity of heat! The earth's crust is only a few kilometres thick. In the vast underlying mantle the temperatures are in the range of thousands of degrees Celsius.

But my main criticism of the book arises in connection with the significance of population growth and size for climate change. Bear in mind that as I have already explained, Lovelock recognizes the adverse effect of massive past population growth and the problems posed by the present very large global population. What is more, he thinks that if we can deal with the present threat from climate change, the next task "will be to ensure that our numbers are always commensurate with our and Gaia's capacity to nourish them" (page 141). And as I mentioned earlier, Lovelock thinks we should aim at a stabilized population of about half to one billion.

Even in the last chapter, he has in mind the population problem. Thus he observes that at the global level, some past volcanic events have caused famine, adding "even when our numbers were only a tenth of what they are now" (page 155). Later, he notes that it is not easy to "change our ways enough to stop breeding.." (page 156).

Now at the global level, the human population is likely to increase by between one and four billion by 2050. What is more, most of future population growth will take place in developing countries, where inhabitants have, on average, a very low standard of living. Yet those inhabitants aspire to the same high standard of living as we have in the industrialized world, with the consequence that in developing countries there is likely to be a massive per capita increase in both consumption of resources and carbon dioxide emissions.

There is an urgent need worldwide then, for the adoption of strong population policies. And what a pity that a century ago all countries did not adopt the one-child policy that China eventually adopted. If they had done so, we could have avoided the present climate problem. So why does not Lovelock advocate governments adopting strong population policies to reduce fertility - tax incentives/ disincentives and other measures?

Turning to Europe , as I have already mentioned, Lovelock asks in his last chapter: "So what should a sensible European government be doing now?".

Now the fact is the population of Europe is already greatly above carrying capacity as shown by ecological footprint studies and other evidence. The population of the European Union (EU) as a whole may start to decline before the middle of the present century, according to official projections, but if so, the decline will be slow. And in my opinion that decline may not take place because, and partly through the adverse effects of global climate change in the developing world, immigration from the developing world may increase. And the UK , Lovelock's own country? The UK population is well above carrying capacity and is projected to increase by roughly six and a half million by 2031, with immigration contributing more than natural increase. The relatively high fertility of major ethnic minority groups will contribute to the natural increase component of future population growth, and collectively ethnic minorities also form a major component of the immigration stream. Further, in contrast to the EU as a whole, the UK population is projected to continue to increase slowly beyond 2031 for several decades at least.

Think just of the amount of land that will be required in the UK for housing and related infrastructure as a consequence of this population increase. Some of the land will be taken from the countryside. Some will come from 'brownfield' land, but note that some brownfield land is rich in insects, flowering plants and some other wildlife. This loss of land to development will reduce the area of land which provides us with the ecological services which Lovelock himself recognises are so vital for our survival. And it reduces the area of land that could be used to expand food production, and to a modest extent, bio fuel production.

Now Lovelock is obviously a widely read man. I think it is almost inconceivable that he is not familiar with ecological footprint studies and also the basic features of demographic trends in Europe and the UK. And as we have already seen, Lovelock thinks we may for a while have to give up some personal freedom.

So why does Lovelock not advocate European governments adopting policies to slow remaining population growth and bring about (faster) population reduction, first by tax incentives / disincentives and other measures to control fertility, and secondly by massively restricting immigration?

It could be argued that in global terms, that would be selfish. But in his opening chapter Lovelock rejects that accusation. He writes "..individual nations may need to think of ways to save themselves as well as the world. We in the UK are as we were in 1939 and may soon be, to a considerable extent, alone; our future food and energy supplies can no longer be taken as secure from a world that is devastated by climate change. We have to make decisions based on our national interest. This is neither chauvinistic nor selfish: it could be the fastest way to ensure that more and more nations, driven by their own self-interest, act locally over global change" (page 13). As far as food and energy supplies are concerned, note what I wrote three paragraphs back. We need to keep land in reserve so we can expand food production and to a modest extent, bio fuel production.

In general in his book, Lovelock comes over as a person determined to follow the truly scientific way, making analysis and subsequent recommendations based on the analysis, without fear or favour. He is not frightened to take on the anti-nuclear lobby. He is not frightened to take on the greens, or indeed the whole environmental lobby. But with population, he falters.

It seems to me that there are only two possible explanations for the omission of population control from his menu of necessary actions.

Either he has succumbed to what is known as the Hardinian taboo (named after the American ecologist Garrett Hardin): a sort of psychological failing, supposedly inherent in our psyche, that makes us unable to control our population numbers.

Or, he has given way through fear of reprisals from the politically correct establishment which in my view dominates the UK (and probably many other countries): If anyone dares to point out that our population in the UK, already above carrying capacity, will continue to grow and that this growth now and in the future is primarily promoted by immigration and the relatively high fertility of major ethnic minority groups, they will get labelled at the very least as extreme 'right wing', more likely as 'fascist' or 'racist'. So one organisation after another, one scientist after another have not draw attention to these basic facts, fearing at the very least that this will 'turn people off' from considering the rest of the message they wish to promote and discredit them in the eyes of the general population.

These criticisms not withstanding, I do hope that many people will read and study this book. Lovelock is right to think we need a change of attitude. But that is unlikely to occur until people realize just what a mess we really are in, and this book will surely help them here.


John Barker,
early May 2006

You may purchase this book at amazon


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Millennium Ecosystem Assessment (2005). “Ecosystems and Human Well-being: Synthesis” ISBN 1-59726-040-1 & “Ecosystems and Human Well-being: Biodiversity Synthesis” ISBN 1-56973-588-3. World Resources Institute.

The Millennium Ecosystem Assessment (henceforth MEA) was conducted under the auspices of the United Nations, with the United Nations Environment Programme playing a coordinating role. The objective was “to assess the consequences of ecosystem change for human well-being and to establish the scientific basis for actions needed to enhance the conservation and sustainable use of ecosystems and their contributions to human well-being”.

The work involved took place between 2001 and 2005, and was carried out by roughly 1360 experts from 95 countries, in four working groups. It resulted in numerous reports being produced, including five 'synthesis' reports: an overall 'Synthesis' Report covering the entire work of the four working groups, and synthesis reports on biodiversity, desertification, wetlands, business and health.

This massive MEA contains a wealth of information about the nature and present state of ecosystems, how they have changed over time including the ways in which mankind has altered ecosystems, the benefits of ecosystems to mankind, and present options for maintaining ecosystems. This is a very wide field of enquiry and I will not attempt a comprehensive review. Rather, bearing in mind the focus of Gaia Watch on population growth, I will focus on the decline of ecosystems and biodiversity, and the role the MEA perceives human population growth has had as a causal agent of this decline and may have for policies designed to mitigate this decline in the future. I will further restrict my review by only dealing with the main Synthesis report and the Biodiversity Synthesis report, apart from referring very briefly at the end to the report of one of the four working groups. This review should be read in conjunction with the review of McKee's book which follows the present review.

Before we get down to the analysis of what the reports say, there are three preliminary matters to mention.
(1) The term 'drivers of change' is used in the reports, where it is defined as follows:
“Natural or human-induced factors that directly or indirectly cause a change in an ecosystem are referred to as 'drivers'. A direct driver unequivocally influences ecosystem processes. An indirect driver operates more diffusely, by altering one or more direct drivers”.
(2) Words used in the reports to indicate judgmental estimates of certainty are:
very certain (98% or greater probability)
high certainty (85-98% probability )
medium certainty (65-85% probability)
low certainty (52-65% probability)
very uncertain (50-52% probability).
(3)The MEA includes four scenarios which were produced to explore possible future changes in ecosystems and human well-being, depending on sets of assumptions about driving forces. So they are not predictions of what will happen in the future.
And now to begin the review.

A figure in the Preface of the Synthesis report (which is given again in the Preface of the Biodiversity Synthesis report) gives the conceptual framework for the whole MEA. It is reproduced here by kind permission of the World Resources Institute.

To enlarge the small (thumb-nail) image, click on MEA immediately beneath it. To complete the enlargement you may have to click again on the partly expanded image or on the little box icon that appears in the image. To then toggle back to this page right-click with your mouse.

Figure B. Millennium Ecosystem Assessment Conceptual Framework of Interactions between Biodiversity, Ecosystem Services, Human Well-being, and Drivers of Change

Changes in drivers that indirectly affect biodiversity, such as population, technology, and lifestyle (upper right corner of Figure), can lead to changes in drivers directly affecting biodiversity, such as the catch of fish or the application of fertilizers (lower right corner). These result in changes to ecosystems and the services they provide (lower left corner), thereby affecting human well-being. These interactions can take place at more than one scale and can cross scales. For example, an international demand for timber may lead to a regional loss of forest cover, which increases flood magnitude along a local stretch of a river. Similarly, the interactions can take place across different time scales. Different strategies and interventions can be applied at many points in this framework to enhance human well-being and conserve ecosystems.
Diagram of interactions

Millennium Ecosystem Assessment ) Copyright World Resources Institute

This diagram is a useful typology (classification of factors). Now our central concern in Gaia Watch in regard to ecosystems, is the influence of human population growth on deterioration of these ecosystems and the concomitant loss of biodiversity; and in this diagram, population growth is subsumed in 'Demographic', one of the Indirect Driver of Change (top right box). So we are particularly interested in the way that the MEA traces out the influence of demographic factors in the total analysis, and we return to this later.

The MEA has 'four main findings', stated in the Synthesis Report as follows:

  • Over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history, largely to meet rapidly growing demands for food, fresh water, timber, fibre, and fuel. This has resulted in a substantial and largely irreversible loss in the diversity of life on Earth.
  • The changes that have been made to ecosystems have contributed to substantial net gains in human well-being and economic development, but these gains have been achieved at growing costs in the form of the degradation of many ecosystem services, increased risks of nonlinear changes, and the exacerbation of poverty for some groups of people. These problems, unless addressed, will substantially diminish the benefits that future generations obtain from ecosystems.
  • The degradation of ecosystem services could grow significantly worse during the first half of this century and is a barrier to achieving the Millennium Development Goals.
  • The challenge of reversing the degradation of ecosystems while meeting increasing demands for their services can be partially met under some scenarios that the MEA has considered, but these involve significant changes in policies, institutions, and practices that are not currently under way. Many options exist to conserve or enhance specific ecosystem services in ways that reduce negative trade-offs or that provide positive synergies with other ecosystem services.

The changes that have taken place make dismal reading. Virtually all of the ecosystems of the globe have now been dramatically transformed by human activity. As the first mentioned 'main finding' indicates, most changes have been made to meet what has been a dramatic growth in the demand of food, water, timber, fibre and fuel. Thus we find:
“Between 1960 and 2000, the demand for ecosystem services grew significantly as world population doubled to 6 billion people and the global economy increased more than six fold. To meet this demand, food production increased by roughly two-and-a-half times, water use doubled, wood harvests for pulp and paper production tripled, installed hydropower capacity doubled, and timber production increased by more than a half”. For example, more land was converted to cropland in the thirty years since 1950 than had been converted in the whole of the period 1700 to 1850. Increased hydropower involved the flooding of vast areas of vegetated land - the amount of water impounded behind dams quadrupled since 1960.
At least one quarter of important commercial fish stocks are over-harvested (category 'high certainty'). From 5% to 20% of global freshwater use now exceeds long-term accessible supplies and is now being met by either engineered water transfers or “overdraft of groundwater supplies” (low to medium certainty).

As for the future, it is thought that about 10 to 20% of current grassland and forestland will be converted to other uses, mainly agriculture and expansion of cities and infrastructure, between the present and 2050. And more generally, as the Biodiversity Synthesis Report page 5 euphemistically puts it in relation to the scenarios of possible future change “all scenarios explored in the Millennium Ecosystem Assessment project continuing rapid conversion of ecosystems in the first half of the twenty first century”. Further (finding 6 page 14), “unprecedented additional efforts would be needed to achieve, by 2010, a significant reduction in the rate of biodiversity loss at all levels”.

We are warned that some changes in ecosystems are nonlinear: “once a threshold is crossed, the system changes to a very different state. And these nonlinear changes are sometimes abrupt; they can also be large in magnitude and difficult, expensive, or impossible to reverse”. One of the examples given concerns regional climate change. The report notes how deforestation generally leads to a decrease in rainfall. And “since forest existence crucially depends on rainfall, the relationship between forest loss and precipitation decrease can form a positive feedback, which, under certain conditions, can lead to a nonlinear change in forest cover”. And to climate change I now turn.

The Biodiversity Synthesis Report notes that recent climate change, has already had significant impacts on ecosystems and biodiversity. And Climate change is projected to have various adverse effects in the future:

  • Exacerbation of biodiversity loss (medium to high certainty)
  • Reduction of water availability in arid and semi-arid regions (high certainty)
  • In some regions reduction of reliability of hydropower and biomass production (high certainty
  • Increased incidence of some vector-borne diseases in many regions (medium to high certainty), increased heat stress mortality (high certainty) etc.
  • Reduction of agricultural productivity in the tropics and sub-tropics (low to medium certainty)
  • Combined with land use change and spread of alien species, limitation of species to migrate and ability to persist in fragmented habitats (no 'certainty' stated)

The Biodiversity Synthesis Report also tells us that during the last few hundred years man has increased species extinction rate by as much as three orders of magnitude. This assessment is only given a 'medium certainty' status for a variety of reasons - we cannot of course know the extinction rate of species not yet found and described, the status of many species that have been described is poorly known, and it is very difficult to be certain about the final extinction of species that were very rare anyway. But based on recorded extinctions of known species over the past 100 years, extinction rates are about 100 times greater than rates characteristic of fossil record species, although some estimates put extinction rates 1,000 to 10,000 times higher than in fossil record lineages. Considering well studied 'higher' taxonomic groups, between 10% and 50% of mammals, birds, amphibians, confers and cycads are currently threatened with extinction.

Among a range of 'higher' groups of organisms, most species are currently declining. This applies to amphibians globally, African mammals, birds in agricultural lands, British butterflies, Caribbean corals, water birds and fishery species. But one needs to consider more than just the decline in the numbers of a species. The many species that human activities have caused to decline tend to be replaced with a much smaller number of expanding species which thrive in environments altered by man. The global outcome is a more 'homogenized' biosphere with lower species diversity.

Decline and extinction is not evenly spread over all ecological or taxonomic groups. Thus species facing a high rate of extinction tend to be at higher trophic levels, have low population density, long life span, low reproductive rate and small geographical range. Also, the degree of extinction risk tends to be similar for related species, which means that whole evolutionary radiations (genera, families) can and have been lost.

All these changes have great significance for genetic diversity, which has declined globally; with domesticated plants and animals there has been a 'substantial' reduction in diversity.

Thinking in terms of 'human benefit', there have been large benefits from actions that have caused homogenization and loss of biodiversity. Thus agriculture, fisheries and forestry “have often been the mainstay of national development strategies, providing revenues that have enabled investments in industrialization and economic growth”. However, such national benefits have not been distributed in an equitable way amongst people:
“Even where the net economic benefits of changes leading to the loss of biodiversity (such as ecosystem simplification) have been positive, many people have often been harmed by such changes. In particular, poor people, particularly those in rural areas in developing countries are more directly dependent on biodiversity and ecosystem services and more vulnerable to their degradation”. And there are trade-offs between ecosystem services. For example, aquaculture farmers may prosper, but by practices which increase soil salinization and thus reduce the rice yield of other farmers and threaten food security for subsistence farmers in the area.

Now how is human population growth regarded in the MEA?

To make an assessment we will first of all consider the Synthesis report. In several places the MEA does recognise harmful effects of human population growth. For example, the report at one point notes how both economic growth and population growth lead to increased consumption of ecosystem services, although actual adverse environmental impacts “depend on the efficiency of the technologies used in the production of the service” (page 64). Here the authors seem to have in mind the famous impact equation I=PAT: Environmental Impact equals Population times Affluence or Consumption times Technology, although they do not mention this equation. They go on “Driving forces are almost always multiple and interactive, so that a one-to-one linkage between particular driving forces and particular changes in ecosystems rarely exist. Even so, changes in any one of these indirect drivers generally result in changes in ecosystems”.

Now this last quotation comes from a section entitled: “What are the most critical factors causing ecosystem changes?” and a subsection on the indirect drivers. The authors re-iterate that there are five major sets of indirect drivers: demographic, economic, sociopolitical, cultural and religious, science and technology. Now one might expect that for each driver set they would say something about the drivers, but then go on to say something about how these drivers affect the direct drivers. Now this is what we find for the last four mentioned indirect driver sets. For example, with economic drivers we read that taxes and subsidies are important indirect drivers of ecosystem change, and an example given concerns fertilizer taxes that “provide an incentive to increase the efficiency of the use of fertilizer applied to crops and therefore reduce negative externalities”. And in the bit on cultural and religious drivers, we read cultural differences clearly have important impacts on direct drivers: “Cultural factors, for example, can influence consumption behaviour...and they may be particularly important drivers of environmental change”. But with the first mentioned indirect driver set, demographic drivers, all we are given are some facts about population growth and migration. There is nothing at all said about the effects of these drivers!

As mentioned earlier, four Global Scenarios to explore possible future changes are developed in the MEA. These vary from each other in matters like the extent of promotion of global trade and economic liberalisation, the extent that global treaties (e.g. on climate change) are implemented and the extent that ecosystem management is proactive as distinct from mainly reacting only to problems once they have become obvious.

In developing these scenarios, human population growth seems to be recognised as a significant factor since demographic assumptions are made for each scenario (fertility, mortality and migration); and in one scenario ('Global Orchestration') we read “The expansion of abrupt, unpredictable changes in ecosystems, many with harmful effects on increasingly large numbers of people, is the key challenge facing managers of ecosystem services”. However, not one scenario includes the situation where any policy is developed directed at reducing population growth through the spread of contraceptive services or the adoption of measures of coercion (e.g. using taxes to promote lower fertility). Yet in our view, such policies aimed at reducing population growth would make a very massive difference to any attempt to conserve ecosystems and improve human well being. Indeed we agree with McKee (in his book which is dealt with below), that we need to take steps to curb population growth. And we believe that unless this is done, no amount of other action will effectively halt the decline in ecosystems, the extinction of species, and the improvement of human well being.

There is one more major section in the Synthesis Report where we might reasonably expect something to be said about the need to take steps to reduce population growth, and this is section 8 of “Key Questions in the Millennium Ecosystem Assessment”, a section entitled “What options exist to manage ecosystems sustainably?”

This is a large section (nine pages) which gives many options (referred to as 'promising interventions'). These options are grouped under headings such as Institutions and Governance, and Economics and Incentives. None of the specific interventions mention population policy or population control. In fact the only statement which does so in the whole section is in the introductory paragraph of the Social and Behavioural Responses sub-section:
“Social and behavioural responses - including population policy; public education; empowerment of communities, women and youth; and civil society actions - can be instrumental in responding to ecosystem degradation”. But nowhere is 'population policy' enlarged on.

Overall, we can see that the MEA, as summarised in the main Synthesis report, treats population growth as a given, something that has harmful effects, effects we should try to ameliorate, but they do not go on, in this summary report, to specifically advocate action to control and reduce population growth. They nearest they get to this is on p.19 where we read:
“Ecosystem degradation can rarely be reversed without actions that address the negative effects or enhance the positive effects of one or more of the five indirect drivers of change: population change (including growth and migration), change in economic activity (including economic growth, disparities in wealth, and trade patterns), sociopolitical factors (including factors ranging from the presence of conflict to public participation in decision-making), cultural factors, and technological change”. Then once again the authors point out the interaction between population growth, consumption and technology and go on “too often, actions to slow ecosystem degradation do not address these indirect drivers”. Then they give an example. Will they involve population growth in their example? Well here is the example:
“For example, forest management is influenced more strongly by actions outside the forest sector, such as trade policies and institutions, macroeconomic policies, and policies in other sectors such as agriculture, infrastructure, energy, and mining, than by those within it”. No, the example does not mention population growth. One gets the impression the authors shy from suggesting any need to develop population policies.

I now turn to the Biosynthesis Report to see how human population growth is regarded there.
Again, human population growth is acknowledged as a cause of biodiversity change. On page 8, in the section entitled “What are the causes of biodiversity loss, and how are they changing?” and the opening paragraph on indirect drivers, we read “in particular, growing consumption of ecosystem services (as well as the growing use of fossil fuels), which results from growing populations and growing per capita consumption, leads to increased pressure on ecosystems and biodiversity”. So we see human population growth linked with growing consumption. And on page 13 we find this expanded to the full I=PAT formulation by including technology:
“Consumption of ecosystem services and nonrenewable resources affects biodiversity and ecosystems directly and indirectly. Total consumption is a factor of per capita consumption, population, and efficiency of resource use. Slowing biodiversity loss requires that the combined effect of these factors be reduced”.

Note how population is shifted from its first position in I=PAT, to second position. But at the same time, this statement could be interpreted as hinting there is a need to slow population growth. But I do not think the authors actually have this in mind. And I note that this statement is in a major section of the report “What action can be taken?” This consists mainly of a long bullet point list in which the above statement comes in a bullet point “Addressing unsustainable consumption patterns” which is only item 15 out of the total of 20 items. Later in the report is the major section 3 “What are the current trends and drivers of biodiversity loss?” and a subsection “drivers of biodiversity change and their trends” where we read (page 47):
“Changes in biodiversity and in ecosystems are almost always caused by multiple, interacting drivers. Changes are driven by combinations of drivers that work over time (such as population and income growth interacting with technological advances that lead to climate change) or level of organization...”. And on page 49, at the beginning of a subsection on indirect drivers, we see population growth being given a significance greater than in any of the other sections I have so far quoted from or mentioned:
“Biodiversity change is most clearly a consequence of the direct drivers. However, these reflect changes in indirect drivers - the root causes of changes in ecosystems. These can be classified into the following broad categories: change in economic activity, demographic change, sociopolitical factors, cultural and religious factors, and scientific and technological change” (my italics), although I note again demographic factors (which is where human population growth fits in) are given second place (to economic factors).

But now lets put this in the perspective of the amount of space this section gives to indirect drivers and direct drivers. The former gets less than half a page, while direct drivers get several pages before the section drifts into discussing indirect and direct drivers together!
There is one more major section in the Biosynthesis Report where it could have been proposed that efforts should be made to curb human population growth, and that is section 5 “What response options can conserve biodiversity and promote human well-being?” of the “key questions” part of the report. This section corresponds to section 8 in the Synthesis Report I have already referred to.

Again the significance of indirect drivers is stated, right at the beginning of the section (page 69), where after briefly writing on direct drivers we find “However, these drivers are better seen as symptoms of the indirect drivers, such as unsustainable patterns of consumption, demographic change, and globalisation”. But why did they not be more specific and state “such as unsustainable population growth”!

On page 73 we read “indirect drivers like globalisation and international decisions on trade and economics often have a negative effect on biodiversity and should be addressed at the international level...”. But the authors do not mention the indirect driver human population growth. Then on page 81 we read:
“Addressing the indirect drivers of change may also require somewhat longer time horizons given political, socioeconomic, and demographic inertias. Population is projected to stabilize around the middle of the century and then decrease. Attention also needs to be given to addressing unsustainable consumption patterns”

This is clear evidence of my contention that the MEA regards human population growth as a given, not as something requiring intervention. “Attention also needs to be given to addressing” - but they have not 'addressed' population growth, they have simply stated it! And note that even if the population does stabilize around the middle of the century, it will probably have increased by roughly a third - an increase of roughly 2.5 billion.

My overall conclusion on the attitude of the MEA to human population growth is then, that this growth is regarded only as a fact, a 'given' to which mankind must adapt its strategies. It is not something that requires active intervention to mitigate ecosystem and biodiversity loss successfully. And in my view, this is a fundamental flaw in the MEA. Bearing in mind that governments around the world no doubt regard the MEA as authoritative, and if human population growth has the significance I believe it has, the MEA may do more harm than good by failing to point out, by distracting attention away from, the need to control the human population. I agree with the conclusion of McKee (next review below) that there are twin requirements for a strategy to effectively mitigate ecosystem decline. One is active conservation of the natural world; the other is to practice human population control.

Nevertheless the MEA project was a herculean task which, as far as I can tell from my limited investigation, and with my additional qualification about the role of human population growth, was well carried out. The MEA reports are clearly a very valuable source of information for ecologists and policy makers; a brief perusal of the main working group reports shows that just the many references at the end of the chapters justify that conclusion. And although I have criticisms of the policy responses, the report of the working group on policies mentioned in the footnote below, with its analyses of constraints to policy making, will be invaluable for policy makers.


There is one report highly relevant to an evaluation of the approach of the MEA to population growth that I have not mentioned, although it must be pointed out that the overall Synthesis Report does take this report into account. This is the report of one of the four working groups, the Responses working group, with the title “Ecosystems and Human Well-being: Policy Responses”.

This is an extremely long (636 pages!) discussion of types of response, responses at different levels (local, national, international) how responses interact, what are the 'enabling' factors, and the 'binding constraints' that make policies feasible or infeasible, past policy responses and the potential for new responses. However as I expected having studied the main Synthesis Report, I could not find any clear advocacy of population policies in this report.

John Barker

You may download the synthesis reports at no cost. Bear in mind that downloading large reports takes quite a long time.
Download the overall Synthesis Report *  Download the Biodiversity Synthesis Report *  You can buy the Synthesis Report (paperback) from Amazon. * 
You can buy the Biodiversity Synthesis Report (hardcover) from Amazon.

The other reports of the MEA may be purchased from Island Press  *  or they may be downloaded by chapter, clicking on "View chapters".

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McKee, J.K. (2003). "Sparing nature. The conflict between human population growth and earth's biodiversity". Rutgers University Press.
ISBN 0-8135-3141-1

This is an important book on an important subject, and I think it is appropriate to attempt to summarise the author's argument in detail. I put my critical comments at the end in a separate section. So this review has two sections, content and critical comments.


McKee starts in Chapter one with two propositions. The First is that "there is a very close relationship between biodiversity loss and human population growth". He immediately goes on to assert a causal connection between these two phenomena: "Quite simply, the more people there are, the more we push aside wild plants and animals. As our population has grown, other species have had to adapt to living in confined reserves or enclaves, lest they go extinct. But over the planet as a whole, there are fewer chances for species to survive as we continue to increase our numbers so dramatically, with a net gain of over 200,000 people every day". The second proposition is "the most important conservation measure we can take is to slow or halt the growth of the human population".

In chapter two McKee introduces, and in chapter three develops, an idea that Charles Darwin used to illustrate natural selection: nature may be thought of as a yielding surface into which very many sharp wedges are driven in close together. Sometimes as one wedge is struck, another one falls off. Normally the wedges are conceived as being variant races within a species. But the idea can be extended to think in terms of more and less successful species. And to McKee, the human species is the most successful wedge of all. And he applies the idea straight away to the evolution and spread of the genus Homo.

McKee argues that the evolution of man in Africa and spread to other parts of the world is correlated at each stage with mass extinctions of other mammal species. In Africa itself, after the appearance of Homo erectus, other African mammals started to go extinct at an unprecedented rate. Outside of Africa, the spread of H. erectus and later Homo sapiens to and in the different continents was associated with mass extinctions of large mammals. McKee provides evidence to support his contention that the spread of Homo was the primary cause of the mass extinctions, although he accepts that climate change played a part.

In Chapter four McKee discusses the possible relationships between the spread of agriculture and biodiversity decline. But first he addresses the issue - what was the relationship between human population growth and the development and spread of agriculture?

Based on an estimate of global population growth rate in the thousands of years before the industrial revolution, McKee constructs a graph of population growth from 100,000 years ago to the present. This graph shows the familiar exponential growth curve.

Now he places the origins of agriculture at around 10,000 years ago in the Middle East, around 8,500 to 4,000 years ago in other regions of the world. "In terms of geological time, it all happened in a blink of an eye". And it is around 10,000 years ago that "the population numbers start to take off dramatically". McKee argues that this accelerated take off was basically just a consequence of the nature of exponential growth rather than being caused by the development and spread of agriculture. Nevertheless while not accepting the simplistic notion that it was the introduction of agriculture that caused the accelerated upswing in the population growth curve, this introduction was part of a feed back loop which caused the accelerated population growth: Population growth spurred the origins of agriculture, and agriculture fuelled population growth.

McKee argues that the development of agriculture inevitably led to loss of biodiversity:

The development of agriculture is the story of the more efficient capture/concentration of energy for food production. Take for example clearing forests to create agricultural land. A forest is much better at assimilating energy from the sun than is a field of corn. A basic reason for this is the much greater biodiversity in forests compared with fields of crops:

"Tall trees gather most of the sunlight, but plants in other levels of the forest are adapted to produce with less sunlight. The ecological interactions of many plants and animals maximize the assimilation of energy from the sun and nutrients from the soil". The trouble is that the forest is not as good as a field of corn "at producing concentrated foods for human consumption". In more general terms, agriculture necessarily reduces biodiversity - a large field with a single crop has little diversity of either species or genes; soil fauna is also less diverse.

McKee goes on briefly to consider ancient civilisations. Agricultural activities led so often to a reduction of the productive capacity of soils through soil erosion and soil salinization. While the collapse of some ancient civilisations seemed to occur at times of 'climate downturns', McKee argues that it was a combination of population pressure and climate change which brought about collapse.

McKee ends his chapter by noting that "further increases in agricultural land must necessarily result in habitat destruction, just as has been the case since the origins of agriculture ten thousand years ago". Based on the work of Tilman and colleagues, if past trends continue, by 2050 the amount of agricultural land needed will be 18 percent more than it was in 2000. This represents the world-wide loss of natural ecosystems of an area larger than the United States.

Chapter five begins, in effect, with a short very elementary course on the processes controlling population growth (demography). Fertility and mortality are the prime determinants of population size change, but for any region of the globe, migration is also a determinant. McKee goes on to explain the importance of the age structure of populations and also gives an account of the 'demographic transition'. He enlarges on exponential growth and uses saving for retirement to illustrate the basic principle. People put in the same amount of money each year at the same interest rate, to build up their retirement funds. "More money makes more money as each year you add to the principal; likewise, people produce more people, regardless of the growth rate. It is compound interest".

Exponential growth produced the accelerated increase of the human population, which he then details. Most fundamentally, he notes that it took 100,000 years for the human population to grow to three billion - the 1960 population size, although nearly half that number had been added only very recently - since 1900. But then it only took 39 years to double the population to six billion - sometime in 1999. And to help us to understand just how massive population growth currently is, he writes that it takes only 38 days for total world population to increase by a number equal to the present population of New York City!

Global population growth continues. And United Nations projections suggest growth will continue until population size reaches eleven billion people around AD 2200, by which time the point of zero population growth would have been reached. That is a massive further increase. But long term projections, both in terms of the largest population size that will be reached and the timing of that event are very unreliable. Much depends on the extent that the 'demographic transition' takes place across the world.

McKee explains, as we also explain in the global section of our Population Trends page, in presently industrialised countries, the population growth rate increased over many recent decades (McKee says from 1850 but we would put the start much earlier). McKee discusses this in terms of the demographic transition and the timing in that transition of mortality and fertility decline. Now while mortality rate in 'developing countries' has generally declined, and fertility rate has declined considerably in some of these countries, in others there has been little reduction in fertility rate. Further, it is uncertain whether or not the demographic transition will be completed in developing countries, yet it is in these countries where most of the present population growth is taking place.

McKee comments on the significance of continued population growth for other species on the planet. His concern is that species not already 'squeezed out' by our large population, will be driven to extinction by the massive wedge of eleven billion people. Certainly, a human wedge of this proportion "can only have negative consequences for biodiversity".

He explains his concerns by considering the global allocation of land for various purposes, based on an analysis by J. Cohen. He lumps together marginal environments such as the arctic, and land already covered over in buildings or used for reservoirs and recreation, as 'nonarable' land, land useless for agriculture, which he says takes up 72% of the world's surface. The remaining land can be divided into three categories - 'food' (12%) 'wood' (land needed for wood used in cooking or in building)(4%) and 'fallow' (the remaining land, which is where most species live) 12%. This does not look too bad as far as biodiversity is concerned. But if the world population grows to eleven billion, much more land will be needed for food (22%) and for wood (7%) and there will be no 'fallow' land left. And "we need fallow land for nature to conduct all its tasks of regeneration. We need other species to conduct those services - decompose wastes, recycle carbon, build soil, produce the oxygen we breathe, and so on". So McKee writes that the really important question is not 'how many people can the earth support?', but, rather, 'how many people can the earth sustain?'.

McKee then goes on in this chapter to get to the heart of the matter - the relationship between human population growth and biodiversity loss. He prefaces this section with information about recent extinctions and estimates of future extinction rates. And he also notes that out of all known plant species on the planet, at least one in eight is threatened with extinction or near extinction.

McKee's account of the attempt to find out if and to what extent human population growth correlates with and may cause biodiversity loss reads like a detective story. The work was done primarily on mammals and birds since we know more about the species of these groups than in most other groups.

It seemed obvious at the start that countries with relatively high human population growth rates would have more threatened species. But no such correlation was found by investigators. However it was then found that another factor besides just growth rate must be taken into account.

For there may be countries included in the analyses which have high growth rates, but there were few people there to begin with so that the high growth rate, at least for some time, may have little effect on species diversity. So investigators then decided population density might be a better variable to investigate. Sure enough, the new analyses, still working with the two most comprehensively studied groups, mammals and birds, did show a statistically significant correlation between human population densities and the number of threatened species.

However, further analysis showed that the strength of the correlation relied heavily on data from island countries. "Islands tend to quickly acquire dense populations, and animal diversity is quickly squeezed out by the 'weed mammal' humans". Restricting the analyses to continental countries, the correlation was weakened.

Further examination of available data introduced other complexities into the story. For example, investigators found that there was some correlation between the number of threatened animal species and average country temperatures. And human densities and fertility rates were correlated with other climatic variables. Nevertheless, when all the various complicating factors were taken into account in the statistical analyses, the conclusion was that "there is an undeniable relationship between human population density and the number of animal species threatened". And country population densities were found to be able to account for about 40 percent of the variability in the number of threatened animal species.

The question then arises, how to account for the remaining 60 percent? Investigators then tried out various statistical models to see which had the greatest explanatory value. They finally found that a model which just used human population density and number of species in a given area (species richness) accounted for 88 percent of the variability "in the relative frequency of threatened species across continental countries".

What then does this tell us about future changes? McKee suggests the average country will have a 14 per cent increase in threatened species by 2050. This is equivalent to four species per year. And McKee points out that in terms of evolutionary time, 50 years is just a brief moment in time.

McKee goes on to discuss what are known as global "hot spots". These are defined as "areas featuring exceptional concentrations of endemic species and experiencing exceptional loss of habitat". There are 25 of these hot spots, where 44 percent of all known plant species and 35 percent of known vertebrate animals are found.

But these hot spot areas are threatened. Taken together, only 12 percent of the hot spots' original areas remain relatively undisturbed. Further, with hot spots, human population growth rates are on average 1.8 percent annually, compared with a global average of 1.25 percent. Many of the hot spots are in tropical, warm, wet regions, and such conditions seem to promote human fertility.

Growing human populations may adversely affect biodiversity in hot spots and other areas in a variety of ways. It may be that an important oil field is discovered in a hot spot area and politicians wish to see it exploited. The Wolong Nature Reserve in China is meant to protect the giant panda. But since the reserve was established in 1975, the human population increased by 70 percent, and the number of households more than doubled. Unfortunately, the best terrain for the panda is a popular source of firewood for the human population, so the panda's habitat is being degraded.

McKee sees the only solution to the problem of global conservation is to stem the growth of the human population.

In chapter 6 McKee goes on to consider habitat loss throughout the world and its consequences for biodiversity. The gradual reduction of total habitat sizes leads to reduction in biodiversity. But it is not just the reduction of total area of given types of habitat that is the problem. The problem is also habitat fragmentation.

Habitat fragmentation leads to reduction of biodiversity in a number of different ways:

  • Many animals cannot find enough food, let alone mating partners in remnant patches of their former environment. This is particularly true of large carnivores like the wolves and jaguars. They need meat, and need to range quite widely to get enough of it.
  • Habitat fragmentation tends to lead to populations of species getting packed into tighter quarters, making it easier for disease to spread.
  • Dividing up habitats into fragments increases habitat edges. Such edges have a distinctive floral and faunal composition. In general they tend to harbour fewer species, so there is usually a loss of biodiversity within these areas. But not only that. Secondary growth of less diverse weedy vegetation takes over on disturbed edges. But these species are often invasive, and this secondary growth often gradually leads to the forest edge receding.

There is a corollary from the effects of habitat fragmentation for conservation:

"Whereas saving small patches of land is a noble endeavour, it is thus not a sufficiently promising strategy for maintaining biodiversity, particularly for species who need lots of space. More propitious results would come by keeping the human population from spreading into those lands in the first place".

Chapter seven focuses on water, and the many ways that human populations have reduced species biodiversity by water-related activities. For me, this is one of the most telling chapters in the whole book.

He starts with an impressive example of the effects of overpopulation, by turning to one of the world's major rivers, the Yellow River in China. Each year since 1985, the river has run dry for part of the year. And in 1997 it failed to reach the sea for 226 days. The main reason is that on its way to the sea, the river's waters are diverted into fields for agriculture and into the growing cities for consumption, sanitation and industry.

He details the adverse effects of building dams. The most basic effect is simply that if you divert water for human needs, you reduce the amount of water available for other purposes such as the support of wildlife. Also, dams involve the flooding of large land areas. Since dams are not built in densely populated areas, this means that what is lost is areas where other species can live.

Building dams, and increased withdrawals of water from rivers, has had a devastating effect on biodiversity. More than 20 percent of all freshwater fish species are now endangered because dams and water withdrawals have destroyed the free-flowing river systems where they thrive. Worldwide, 26 kinds of salmon are threatened with extinction, with further threats to their genetic biodiversity.

Man's pollution of lakes and rivers has increased as human populations have increased. Many years ago with many lakes, one might safely drink the water, but this is no longer so. More and more people swimming in the lakes and doing other things as well have increased the lakes' bacteria populations. Runoffs of fertilisers from agricultural lands also make the water unsafe to drink, and combined with the run off of soils, lead to the eutrophication of lakes (and rivers). Trees are cut down by lakes, for camp sites, scenic highway, etc. This reduces leaf fall that feeds micro-organisms which form the base of lake ecosystems. But this also removes shade which minimises temperature variation, so important for those plants and animals that live close inshore. And industrial pollution causes increase in temperatures - thermal pollution.

Increased use of waterways for transport and pleasure has led to the spread of many species which hitchhike on vessels. This not only leads to the increasing 'homogenization' (loss of between area species diversity) of the world's water fauna, but allows the spread of species which, proliferating in the new environments, disrupt local ecosystems.

Oceans have suffered from increased fishing to provide food for the ever growing human population. McKee thinks over fishing has been more destructive of ecosystems than pollution and habitat destruction. He notes that large mammals that rely on fish are in competition with humans for food and have now largely abandoned coastal regions world wide. The effects of over-fishing, carry on down the food chain. People tend to take the larger fishes at the top of the food chain, "so the initial effect is a decline in their populations, sometimes past the level of survivability. Once one species is gone, other similar predators become the target of over fishing. The big fish eat the little fish, so a decline in the number of aquatic predators leads to a burgeoning of the populations at lower trophic levels. These populations then become more dense and are more subject to outbreaks and the rapid spread of disease".

Fish farming has increased greatly. Some people hope that we may get sufficient protein from such farming to successfully feed the growing human population. But as McKee observes, "there ain't no such thing as a free lunch": the farmed fish need food. And ultimately this comes from the phytoplankton of the ocean, thus reducing the food available for wild coastal animal populations. Some farmed fish are fed smaller fish. But where do they come from? Largely from wild populations. And "many intensive and semi-intensive aquaculture systems use 2-5 times more fish protein, in the form of fish meal, to feed the farmed species than is supplied by the farmed product".

McKee turns to the issue of total human water consumption and available supplies. He believes that as human populations continue to grow, there will not be enough to go round. Already man uses about half of the earth's usable fresh water. And by 1995 a third of the human population was living under conditions of relative water scarcity.

McKee concludes there is only one "sustainable solution" - stop the growth of the world's human population.

In chapter 8 McKee turns to conservation and tries to show why conservation is important for the future of mankind. And he attempts to show that "our pension plan for nature must include a diverse portfolio".

He focuses first on tropical forests. These have high species diversity and make up the majority of the world's hot spots. But "the value of tropical forests is not just the high species diversity that characterizes such parts of the world, but the vital services such ecosystems perform, which are necessary for preserving the way of life of people like us, living thousands of miles away".

Tropical forests, together with boreal (and other) forests, extract carbon dioxide from the atmosphere, converting it into the materials of their bodies - they are 'carbon sinks', mitigating global warming. And when we burn down forests to make way for agriculture, we release most of the stored carbon back into the atmosphere as carbon dioxide.

Whereas forests absorb heat, denuded patches of earth heat up, causing localized areas of dry heat that can disrupt regional weather patterns. But forest trees also pull up water from the soil and transpire it back into the atmosphere, making rain clouds. Without trees and other plants to recycle water, areas like the Amazon basin would lose significant amounts of rainfall, as would other parts of Brazil where crops are grown.

Natural grasslands also act as a carbon sink, but unlike forests, most of the carbon is stored in the soil. And natural grasslands are more effective than farmed fields at absorbing rather than reflecting solar energy. And the extensive root systems reach deep down into the soil reaching water that is then transpired into the atmosphere. "Thus the world's climatic regime is held in check, at least in part, by the natural services of grassland ecosystems".

There has been much soil erosion on farmlands across the world, caused by tilling, planting monocultures, overgrazing and trampling by cattle. "Not so in natural grasslands, which have perennial root systems that nurture the soil and prevent its erosion. Indeed, the wild grazing animals such as bison help to maintain the system by stimulating the growth of new shoots, and by leaving deposits of natural fertilizer".

But perhaps the greatest value of natural grasslands concerns genetic diversity. Our crop plants evolved from plants in natural grasslands. But while these plants have been adapted to human needs, this adaptation has been achieved at the price of loss of genetic variability. So natural grasslands are needed because they hold a 'genetic library' for the development of future crop strains.

Later in the chapter McKee enlarges on genetic diversity, not just in grasslands but other ecosystems as well. He claims that more than half of all prescription drugs are modelled on natural compounds, and about a quarter are taken directly from plants or are modified versions of plant substances. So wild plants have a vast potential for providing man with cures for many diseases.

But McKee notes that most wild species vary considerably in their genetic makeup. Not all the individuals on the species may produce the particular compound that could help to cure a disease. The implication is that we need to maintain large natural populations.

Turning to rivers and marshes, McKee observes that they are more than home to many species of plants and animals and other organisms, so their importance is not confined to the fact that a significant portion of total world biodiversity lies within them. First of all, they provide us with food. Second, they also supply water to the natural ecosystems on land which are valuable for mankind. But marshlands have been drained worldwide.

Rivers, lakes and oceans contain the organisms which transform our waste products into nutrients for the food chain. Swamps may stink, but they absorb flood waters and thus can save cities downstream from flooding. Plants round the ocean shore and in estuaries hold the land together, preventing loss of coastal land and mitigating the effects of hurricanes.

McKee turns to the complex interrelationships between species in ecosystems

In natural ecosystems, of particular importance are what are termed 'keystone species'. These are species that play a disproportionately important role in the ecosystem - "the metaphorical heart of the ecosystem". If such a species dies, then the whole ecosystem may decay and die.

Keystone species are often predators, which help to keep in check numbers of other species and maintain a balance between species. But nor all keystone species are predators. In fact the problem is that keystone species are often difficult to identity. They could be anything from a bacterium upwards. But for keystone species that can be identified, "conservation programs can gain focus and relatively quick success".

In the final, ninth chapter McKee invites us to consider the speed of human population growth and the speed of extinction of other species. In the time between when we get up in the morning and go out to work, 22,530 babies are born. Meanwhile, 9,418 people die. So there is a net gain of 13,112 people in such a short time. But this same short time also sees the end of at least one entire species. And, McKee asserts, the gain in the number of people and the loss of other species are related.

Looking ahead, there are two main things we must do to ensure the long-term sustainability of both the human population and biodiversity. One is active conservation of the natural world; the other is to practice human population control.

As far as conservation is concerned, he divides possible measures into 'simple' and 'complex'. Simple measures include things like turning down the thermostat in winter. Complex measures are more problematical. We still have insufficient understanding of how ecosystems work, despite considerable progress made. This makes conservation difficult. Consequently, while some past conservation efforts have succeeded, others have failed. Hopefully we are learning from our mistakes, but time is not on our side. And if we can instill an understanding of the values of biodiversity in the minds of people, this might lead to more urgent conservation action.

McKee considers however, that the "most effective conservation tactic we have" is to extend family planning. But we have to consider " freedom of choice. We cannot take away someone's right to have many children". And he goes on "And that brings us back to Garrett Hardin's tragedy of the commons: freedom in the commons brings ruin to all. Can we afford reproductive freedom, or should we impose a limit? A limit of one child per couple was imposed by China, and since abandoned. Dare we repeat the mistake?".

Actually it is not entirely clear what McKee thinks was the mistake, imposing the limit or abandoning it, but I suspect the former.

McKee notes that Hardin thought the answer was "mutual coercion, mutually agreed upon", but he thinks this is difficult to achieve. Nevertheless he does think that "we can craft subtle coercion" and he writes of using appropriate tax breaks.


I have the following critical observations to make about this book.

By looking at biodiversity from many different angles, McKee enables non-specialists to understand both the nature of biodiversity, and the nature of the threats to that Biodiversity. He manages to avoid oversimplifying what is a very complex subject and brings out clearly the various interactions between the various processes operating within and upon ecosystems.

This is no dry-as-dust academic book. Rather it is full of interesting examples at local levels which challenge the reader to think through mechanisms of biodiversity change. Here is an example.

If you go to Beijing one notices two things. First, "an almost deafening buzz, loud enough to nearly drown out the din of constantly ringing bicycle bells". Where does the noise come from? It comes from cicadas in the trees, cicadas that far outnumber people. Second, "the lack of birds in the air". Why are there so many cicadas, and why are there no birds? The two phenomena are related.

McKee explains it this way. In the 1950s, the Chinese government realised the crisis cause by population growth, as the ability of people to feed themselves was diminishing. Later they would adopt the one child policy. But at the time they decided on another solution: Sparrows were eating people's grain, out competing people. So they had to go.

The citizens of China shot them, destroyed their eggs and nests and went out everyday to bang pots and pans "to scare away the birds when they tried to land; eventually the birds died of exhaustion and starvation".

However, birds do not just eat grain. They also eat insects. In the absence of birds insect populations grew rapidly and too late the Chinese realised "the ecological devastation they had wrought by their policy of taking over nature". The large numbers of cicadas in Beijing are one consequence of this policy.

The fact that there are numerous interesting examples in the book may perhaps have contributed to what I think is one fault of the book - it is sometimes discursive. This is particularly so in chapters five and six, and as I read these chapters I felt the thread of the argument was being obscured.

While some features of human population growth are mentioned in earlier chapters, especially chapter four, it is not until chapter five that we get a full exposition of the basic demographic features of that growth. Since human population growth is a central preoccupation of the book, and is for McKee one of the main causes, perhaps the main cause of biodiversity decline, it would have been better if it had been dealt with fully near the beginning.

Turning to the relationship between population growth and the development of agriculture (chapter four), the agricultural revolution increased food supply. But was it increased rate of population growth that caused the development of agriculture and the resultant increase in food supply, or was the causal relationship the other way round? McKee calls this the classic chicken and egg conundrum - which came first. McKee's conclusion, as I wrote earlier, is that during the period when agriculture first developed, increased rate of population growth was not caused by the development of agriculture, it took place simply because of the inherent nature of exponential growth:
He writes in relation to the graph of human population growth “I've seen similar graphs from archaeologists who use what little evidence we have to show that the human population grew after the origins of agriculture. Indeed it did! But the point is this: it did not grow because of agriculture but grew anyway, in some respects despite agriculture. There were more humans because there were more humans making more humans - that is simply the nature of population growth, even at the slow rate of 0.02033 percent per year. It is simply the product of more and more people having children, and reaching a critical mass that had not been reached in earlier interglacial ages” (my italics).

But a little later he also writes "What ensued was a positive feedback loop, or autocatalytic process: population growth spurred the origins of agriculture; agriculture fuelled population growth".

One is left rather in the air. But more fundamentally, McKee seems to confuse mechanism with cause. The mechanism of this exponential growth is as McKee explains - "there were more humans because there were more humans making more humans", like a bank account with fixed-rate compound interest. But there has to be a cause of the exponential growth. And in animal populations, the cause of exponential growth is an unlimited food supply. And McKee himself acknowledges "it is true that without agriculture the population may have stopped growing. There were simply not enough resources on earth to allow foraging populations to continue their way of life and increase their numbers".

I was surprised that a major recent contribution in this field - the 2001 paper by Hopfenberg and Pimentel in the journal Environment Development and Sustainability was not mentioned. Because these authors, instead of ascribing the change in population growth rate basically to the intrinsic nature of population growth, came down firmly to the conclusion "there is overwhelming evidence that food surplus explains, i.e. is causally related to, human population increases". For these authors, as they make very plain in their paper, rather than seeing population growth as the independent variable, they see food production as the independent variable, population growth as the dependent variable: "Our position is that population growth, the prime environmental problem affecting all ecological, biological and non-living systems, is a function of increasing food production". And:
"The agricultural revolution produced human food surpluses, through a program of expansion and elimination of competing cultures and species...The resultant food surplus is both necessary and sufficient to explain the meteoric rise in the human population in only 500 generations. Based on the experimental evidence, the correlation data and the seeming coincidence of agricultural expansion and the prodigious human population increases, there is overwhelming evidence that food surplus explains, i.e. is causally related to, human population increases".

Now this particular hypothesis of a general causal relationship between food supply and population growth is not accepted by many people, but if it is true, it has important implications for the whole question of what man should do to stem the continued biodiversity loss, the subject that McKee addresses in his final chapter.

McKee concludes we need to take steps to curb population growth, and to this end "we can craft subtle coercion" to ensure people have fewer children.

But if Hopfenberg and Pimentel are right there is something else we should do - halt increases in food production. They conclude:

"Thus, there appears to be two available systematic methods of population control. One is to continue to fuel population growth through increased food production and allow biological mechanisms such as malnutrition and disease to limit the population by means of an increased death rate. The other is to cap the increases in food production and thereby halt the increases in population by means of a reduced birth rate".

Better, I argue, to let starving people die now, rather than have very, very many more starving people dying later. Of course it is very politically incorrect to make such a suggestion! Continuing to increase food production will, if Hopfenberg and Pimentel are right, only fuel population growth and thus fuel habitat destruction, ecosystem destruction, and species extinction.

Turning from information content of the book to presentation, a criticism on the quality of illustrations: As far as the few photographs are concerned (pages 24, 39, 43, 53), they are rather blurred, at least in my copy of the book.

All in all, this book is a good read and it will, hopefully, convince at least some doubters first that human population growth is a prime cause of biodiversity decline, and second that for the sake both of mankind and nature, we must take steps to reduce this population growth.

John Barker

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* D. H. Meadows et al. (2004) “Limits to growth. The 30-year update”. Earthscan.
ISBN 1-84407-144-8

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In 1972, a book was published entitled “The limits to growth”, by D. H. Meadows, D. L. Meadows, J. Randers and W.W. Behrens III. The book argued that unchecked growth on our finite planet was leading to ecological 'overshoot' (unintentionally exceeding limits imposed by the environment) and pending disaster. This widely read book provoked a stormy discussion.  Now, 30 years on, three of the authors (Meadows, Meadows and Randers) have produced “Limits to growth. The 30-year update”. The work reported in these books centres on a computer model, the World3 model developed in the Massachusetts Institute of Technology.

The computer model was developed to investigate “a carefully bounded set of questions about long-term physical growth on the planet”. The “core question” was: “How may the expanding global population and material economy interact with and adapt to the earth's limited carrying capacity over the coming decades?”

The model consists of a series of mathematical equations. It incorporates information about “stocks such as population, industrial capital, persistent pollution, and cultivated land”. It investigates how these stocks change through flows, for example births and deaths in the case of population, investment and depreciation in the case of capital stocks. It incorporates interactions between these flows, and contains many feedback loops. It incorporates non-linear relationships (relationships that cannot be represented graphically as straight lines) because in the real world, many relationships are non-linear. And the model is iterative - equations are repeatedly re-run taking into account the effects of interactions including feed-back loops.

By varying key assumptions about the future the authors were able to generate a series of possible future scenarios. For example, scenario 3 differs from scenario two in that a bigger effort is made globally, using pollution control technology, to reduce pollution, including systematically allocating more capital toward that goal. It is important here to realise that improvements in technology, which may reduce environmental impact, cost money and there is always a limited budget, so that a government has to balance the cost of improving technology against other expenditure requirements, and also to decide how much to spend on different aspects of technology - for example pollution control technology versus agricultural production technology.

The authors emphasise that in developing their model, they were not trying to predict the future. Rather they were investigating alternative possible scenarios of future change. Further, they point out that the model has its limitations, and is a “great simplification of reality”.  For example, it does not distinguish between the different parts of the world, it does not treat separately the rich and the poor. And its representation of pollutants is highly simplified.

The authors set the different scenarios against a background of a detailed survey of past changes in population, industrial production, renewable and non-renewable resources, pollution and waste. And they point out that a common feature of past changes has been exponential growth.

What then were the results of the different scenarios? More often than not they show overshoot and varying degrees of collapse, in such things as population, life-expectancy, and industrial output. The authors list four reasons for this:

1. Growth in the physical economy is generally considered desirable - it has become central to our cultural beliefs; and growth of both population and the economy, when they occur, tend to be exponential.

2. There are physical limits to the sources of materials and energy that are needed to sustain the population and the economy. Likewise, there are limits to the capacity of sinks (to absorb pollution and waste).

3. Unfortunately, the signals society receives about physical limits are “distorted, noisy, delayed, confused, or denied. Responses to those signals are delayed”.

4. The system's limits are not just finite. They are erodable when overused. Further there are strong non-linearities - “thresholds beyond which damage rises quickly and can become irreversible”.

However, the authors point our that these very causes of overshoot and collapse offer hope for the future, since they indicate how mankind might change the system to secure a sustainable and manageable future.

What then do the authors really think is likely to happen? Well they do differ here. D.H Meadows “who recently died” was “the unceasing optimist”. Randers “is the cynic”, thinking that mankind will ignore warning signs until it is too late. D.L. Meadows “sits in between”. However, the book says “we are much more pessimistic about the global future than we were in 1972”. I personally share Randers cynicism, especially, as the authors make explicit, the model does not take into account possible wars and labour strikes, and corruption, drug addiction, crime and terrorism. It ignores “struggles over political power or ethnic intolerance or corruption”! And the authors state that consequently, the model “does paint an overly optimistic picture of future options”. Further, as the authors also state, and I agree, the world population is already greater than carrying capacity (for the meaning of 'carrying capacity' see the essay “How many people can the earth support? Part 1. Environmental deterioration and carrying capacity” in the Analysis section of the Comment and Analysis page).

This book is well written and well referenced. The authors carefully explain the technical terms they use (such as 'exponential growth' and 'ecological footprint'). Each scenario is illustrated by a very informative, well drawn composite graph. Comparison of the scenarios is facilitated by the fact that these graphs have a common format. Numerous other graphs and clear diagrams aid the exposition.

While experts seem very divided about the future global situation, the authors of this book have, in this reviewers opinion, and model omissions mentioned above not withstanding, achieved a balanced assessment. I note especially the significance they ascribe to population growth, a central concern of Gaia Watch. While many economists and other analysts downplay the significance of population growth for environmental deterioration and hence the well being of mankind, such growth is a central variable in the model which forms the basis for the book. But the authors put population growth in perspective, when for example, they write:
“Occasionally, however, there arises the potential for catastrophic overshoot. Growth in the globe's population and material economy confronts humanity with this possibility. It is the focus of this book” (my italics). It is important to remember here that this growth in the material economy does not have a one-to-one direct relationship with population growth. It is partly a reflection of the great increase in per capita wealth in the industrialized countries, as the authors make clear.

However, the books layout could be improved. While the index at the end of the book does list the scenarios, the scenario graphs, so central to the purpose of the book, although well drawn and with common format, as I have already said, are scattered through the central part of the book, as are the corresponding scenario descriptions, occasionally separated by many pages not directly connected to the actual scenarios, and then they are unobtrusively introduced without any proper headings. All this delays locating particular scenarios.


John Barker

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* Jared Diamond (2005). “Collapse. How societies choose to fail or succeed”.Viking Penguin. ISBN 0-670-03337-5

  In addition to this review, there are comments on this book on the Comments and Analysis page.
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Jared Diamond, Professor of Geography at the University of California, Los Angeles, attempts to analyse why some past and present day societies have collapsed.
The greater part of the bulk of his massive (575 pages) carefully researched book, consists of a set of case studies of past societies like Easter Island and the Maya civilisation, and modern societies in Rwanda, China and elsewhere. These studies are based on published evidence (archaeological, historical and other evidence), the authors own on-ground explorations, and his interviews with present day residents and analysts. Diamond concludes his book by attempting to draw out from his analyses, practical lessons for mankind today.

In his prologue, Diamond indicates his considered view of the train of events which often underlie collapse, when of past collapses he writes: “Population growth forced people to adopt intensified means of agricultural production” “and to expand agriculture from the prime lands” “onto more marginal land,” “Unsustainable practices led to environmental damage ”resulting in agriculturally marginal lands having to be abandoned again”.
He lists consequences for societies as including “food shortages, starvation, wars among too many people fighting for too few resources” and the overthrowing of government elites “by disillusioned masse”. “Eventually, population decreased through starvation, war, or disease, and society lost some of the political, economic, and cultural complexity that it had developed at its peak”

For each society examined, unsustainable practices were identified, the importance of individual practices for societal decline varying from society to society. Deforestation may have led to soil erosion with consequences such as reduced agricultural productivity or even such a loss of available timber that boats needed for fishing or trade could no longer be made. Food production may have been attempted on land not really suitable for sustained production, so that yields fell off drastically over the years. Animal populations, which succoured a hunting society, may have been over-exploited. On top of such unsustainable practices, climate change sometimes played a significant part in societal decline. For example long term changes of sea temperature might have had adverse effects on agriculture, or on the presence of marine animals on which human populations depended. But amplifying the effects of all environmental factors was population growth, which meant there were more mouths to feed.

Problems arising directly from the physical and biological environment were usually exacerbated by other factors. Sometimes it was hostile neighbours. Trading partners who supplied vital items may have suffered severe population decline through disease or environmental disaster, so that trade could no longer take place. The customs of the people sometimes played a significant role in collapse. Vikings in Greenland abandoned fishing in the early years of the colony, did not learn from the Inuit how to hunt seals and whales, and starved as a result. But one thing that stands out in most of the case studies was that the decline or collapse of the society concerned was caused by several factors which interacted with each other.

One must admire the authors ability to collect and collate so successfully such a mass of interesting, diverse types of information. However, I think the title of the book is somewhat misleading: “Collapse” is rather too strong a word when the case studies include modern China and Australia. And I think the “choose” in the title is not only unnecessarily provocative, but it is surely wrong. Choose is a word of unambiguous meaning, implying a conscious and deliberate act. None of the societies Diamond studied, according to the evidence he presents, ever 'chose' to collapse. Indeed, with a very few exceptions, such as the Jewish revolt at Masada, societies have never chosen to collapse. They may well have been stupid not to notice, or respond to, warning signs, but that is not the same as choosing to collapse.

The case studies make very interesting reading. However the choice of societies to include in these studies was for me rather disappointing. To draw general conclusions about the fate of societies in the world surely demands that collectively these studies deal with a wide range of past societies, including the major civilisations. So it was disappointing to find that the ancient civilisations of the Middle East, about whose collapse so much is known, received only cursory mention, and not one of the case studies is devoted to any of these civilisations.

These criticisms not withstanding, this book provides a very valuable insight into societal collapse and it provides a cogent warning to modern society to mend its ways before it is too late. Also it is a book which shows how population growth has in all the cases examined been one of the causes of societal retrogression or collapse. I end with Diamond's warning from one of the case studies:
“The parallels between Easter Island and the whole modern world are chillingly obvious”.

John Barker

You can buy this book at amazon