NB. This essay was originally posted on our web site 2nd November 2007. Small modifications were made 3rd and 6th November - see footnote 5.
The world human population is projected to increase by 2.5 billion between 2006 and 2050. So the question arises, will mankind be able to increase food supply to keep pace with population growth?
During the recent century, there have been pessimists who argued that in the then near future, human population growth would outrun food supply, which, combined with continued large scale environmental degradation, would lead to a collapse of the human population.
On the other hand, optimists have argued that such a collapse is unlikely. They have pointed to the famous 'impact equation', I=PAT: Environmental Impact = Population × Affluence × Technology. As far as technology is concerned, they have argued that continued innovation, in farming technology and in industrial production and waste processing, will continue both to adequately sustain food production and reduce per capita environmental impact. And with affluence, a reduction in the excessively high standard of living in industrialised countries, with consequent reduction of per capita consumption and atmospheric emissions, will contribute to the mitigation of environmental impact.
Optimists also point out that predictions of disaster that have already been made have so far turned out to be wrong. Perhaps the most quoted example here is that of Professor Paul Ehrlich who in the 1960's wrote: “The battle to feed all of humanity is over. In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now”. And it is certainly true that until very recently at least, food production globally has continued to increase at a rate that has kept pace with human population growth.
On the other hand, this very impressive record of human achievement has come at the price of severe environmental deterioration of soils, grazing land, oceans and rivers that provide the food we eat, and reduction of forests ecosystems that underlie climate stability upon which food production ultimately depends.
And it is also worth noting that current estimates of the carrying capacity of the planet (the maximum number of people the planet can sustain long term at current levels of consumption) indicate that the present world population already greatly exceeds carrying capacity.
And now, new reports together with recent events, suggest to us that there is in fact a very real danger that the doom predicted for so long by the 'doom mongers' is finally overtaking us, and that without extremely drastic and prompt remedial action, the global human population will collapse during the present century and it is even very possible that the world will permanently become, a hardly habitable place.
Falling grain stocks
Food production is one sign. The USA National Farmers Union report based on United States Department of Agriculture projections of world grain supply, which we report on in the 'comment' section of the current page (“will we be able to feed the world population?”), alerts us to a very possible tragedy in the near future:
“2007/08 will mark the seventh year out of the past eight in which global grain production has fallen short of demand. This consistent shortfall has cut global supplies in half — down from a 115–day supply in 1999/00 to the current level of 53 days. The world is consistently failing to produce as much grain as it uses”.
In an United Nations Food and Agriculture Organisation (FAO) report released 5th October we read:
“The global cereal supply and demand situation has continued to tighten in recent months, reflecting the deterioration of prospects for the 2007 world cereal production, which nevertheless is still expected to reach a record high. However, on current indications, this year's harvest would only just meet the expected level of utilization in 2007/08, thus precluding a replenishment of cereal stocks, which are anticipated to remain at very low levels” And “as a result, the world cereal stocks–to–use ratio is likely to remain at around 20 per cent, which would be identical to the previous season's low and therefore the smallest since the beginning of FAO's tracking of the global cereal market some 30 years ago”.
The report calls the situation of wheat stocks “worrying”. And “Sustained demand amid insufficient increase in production this year, especially among the major exporting countries, which are also among the leading stock holders, is expected to result in at least a 14 million tonne drawdown of world inventories to 143 million tonnes, the lowest since 1982”.
Why has global grain production fallen short of demand? Why have global stocks decreased?
There are four basic reasons:
• continued global human population growth;
• dietary change in developing countries;
• increased bio–fuel production;
• extreme weather events.
We now look at each of these in turn
Population growth
The world population has grown massively in the recent (20th) century. At the beginning of the century there were 1.6 billion people. By the end of the century there were 6.1 billion, and in 2007 there were 6.6 billion people. Currently 80 million people are being added to the population each year in less developed countries and 1.6 million in more developed countries.
But it is not just the massive growth that we need to note, it is the speed of this development, the rate of growth. It took the whole century 1800 to 1900 for the population to grow from about 1 billion to 1.6 billion, an increase of only 0.6 billion. Then we had this massive increase of 4.5 billion in the following, 20th century!
There was therefore a massive problem of feeding a rapidly growing population, and this problem was surmounted, at least until very recently. But now the world population may well grow by around 3 billion people from 2000 to 2050 (UN medium variant projection), i.e. in just half a century.
Most of this population growth will occur in the 'developing' countries of Asia and elsewhere. This is very significant in relation to dietary change that we now consider.
Dietary change
More and more people in developing countries are becoming affluent and are changing their diets from a largely plant diet (cereals, vegetables) to a mixed diet that includes meat (and milk). Now the intensive rearing of livestock makes use of vast amounts of feed grain. So some grain production has been diverted from producing grain for human consumption to supplying grain for intensive livestock production. And it should be remembered that an acre devoted to cereal production produces far more protein than an acre used for livestock production — our comment “will we be able to feed the world population?” already referred, explains why.
This dietary change has obvious implications for global food production, especially if we remember, first, that there is a shortage of land suitable to be taken over for agricultural production, and second, this dietary change it is taking place in the world's two most populous countries — China and India.
Bio–fuel production
Across the world bio–fuel production is expanding rapidly. The UN says that global production has doubled in the last five years and is likely to double again in the next four years. There are two reasons for the increase in bio–fuel production. The first is that oil prices have risen (footnote one explains why). The second reason is the mounting concern over the implications of global warming, warming that is being driven primarily by the combustion of non–renewable fuels (oil, gas, coal). Taking into consideration all the factors involved in fuel production and use, bio-fuels produce a smaller net emission of carbon dioxide than fossil fuels.
The increase in bio–fuel production is made possible by increasing the area of land used to produce fuel crops. This is in part achieved by increasing total agricultural area, something that is difficult in some regions where there is little 'unused land' suitable for agriculture left as already mentioned. But in part it is also achieved by diverting land that has in the past been used for human food production to land used for bio–fuel production. For example, in the USA, many farmers in grain producing regions have reduced wheat acreage to increase the acreage of maize used for ethanol production. In fact about a fifth of all US maize is now grown for fuel production. And it should be remembered that bio–fuel production not only diverts land from food production for humans. It diverts water and other resources too.
Extreme weather events
The frequency, severity and global extent of severe weather events vary considerably between years. 2002/2003 for example, was a very bad year in various countries across the globe, and had adverse effects on grain production in some but not all world regions. In the present year, there has been an unusually high incidence across the world of such events. There has been widespread flooding in a belt of countries bordering the southern boundary of the Sahara from Senegal in the west to Ethiopia in the east, and in South Asia (India, Bangladesh and Nepal). Typhoon Krosa hit Taiwan and China causing extensive flooding, and this typhoon is the sixteenth to hit China this year. The 2007 hurricane season in the Caribbean caused devastation. On the other and, severe drought has continued in Australia, and Europe has experienced unusually hot weather and drought. This year has also seen widespread fires in parts of southern Europe, California and elsewhere. While some of these fires may have been started deliberately, hot dry weather plays its part. And in South America, in Paraguay, where prolonged dry weather and high temperatures prevailed, there have been the most severe fires in the history of the country.
Some severe weather events have had serious adverse effects on food production. In Europe, hot dry weather has reduced the cereal crop. This together with global cereal price rises has now led the European Agriculture ministers to reduce obligatory set–aside from 10 percent to zero percent (see footnote two). The continuing severe drought in Australia is forecast to hold both total cereal and wheat production well down from pre–drought levels, although with a substantial increase from the terrible 2006 harvest. In Paraguay, fire has destroyed large areas of cropland (as well as forest)
However, in considering the effects of flooding, we must distinguish effects on food production from other effects. The flooding noted above has caused loss of life, population displacement, destruction of homes and infrastructure. But with food production the situation is more complex. As far as Asia, Western and Eastern Africa are concerned, “in spite of serious localized crop losses, the abundant rains benefited developing crops and overall prospects for the 2007 cereal harvests are favourable in these regions”.
It is not surprising then that recently, grain prices have soared. A contributory factor has been the fact that global freight rates have surged to unprecedented heights, driven by the unrelenting heavy demand for minerals in Asia, causing for example, a big increase in the cost of transporting grain from the USA to Japan.
The FAO report of 5th October already referred to summarises the situation:
“International wheat prices have increased sharply since June, hitting record highs in September in response to tightening world supplies, historically low levels of stocks and sustained demand”. And “the combination of higher export prices and soaring freight rates is pushing up domestic prices of bread and other basic food in importing developing countries, hitting the group of Low–Income Food–Deficit countries (LIFDCs) particularly hard and causing social unrest in some areas”. “The total cereal import bill of the LIFDCs is forecast to increase considerably for the second consecutive year, reaching an all–time high of US$28 billion in 2007/08, up roughly 14 percent from last year's already high level. Overall, developing countries are likely to spend a record US$52 billion on cereal imports, according to the report”.
Developments in the Indian subcontinent have played a major part in causing world grain prices to rise. Last year, the subcontinent swung dramatically from exporting surplus wheat to importing it. And this September, India, the second biggest global consumer of wheat, waded into the global market by trying to buy 50 per cent more of the grain than suppliers were offering, contributing to further global price rises. In fact India imported 6.7 million tonnes of wheat last year to replenish stocks. By the end of the current year, because of higher international prices and improved home production, India is expected to have imported less — 3 million tonnes; but even this is an enormous amount of grain.
We have said nothing so far about fish. But fish are a major diet component in many countries. Marine fish stocks have been depleted across the globe. Indeed stocks have collapsed to less than 10% of original yield in nearly a third of the fisheries. Despite bigger vessels, better nets and new technology for spotting fish, the global catch fell by 13% between 1994 and 2003 (BBC News 2-11-2006 “only 50 years left for sea fish” http://news.bbc.co.uk/1/hi/sci/tech/6108414.stm)
Take for example, the north-western and south-eastern Atlantic Ocean. Fish catches have stabilised here over the last decade, to levels approximately half the maximum reached three decades ago. But ten% of fish species are so depleted they are no longer fished, while another 18% will decline without effective regulation. It is estimated that presently almost half of all fish species are being fished at their maximum sustainable limits.
Considering just the North Sea, evidence suggests the total stock of fish has dropped from 26 million tonnes to 10 million in just over a century by 2004. Some fish, such as the bluefin tuna, have disappeared completely following intensive fishing in the 1960s. Others, including cod, haddock and mackerel, have declined considerably,
Now commercial marine fishing targets the larger species. But the effects of over–fishing carry on down the food chain. Big fish eat little fish, so a decline in the number of larger predators leads to a burgeoning of the populations at lower levels in the food chain. These populations then become denser and so more subject to outbreaks and the rapid spread of disease (McKee, J. K., 2003, “Sparing nature. The conflict between human population growth and earth's biodiversity” — see our Book Reviews page).
But we need to consider not just commercial fishing, but the fishing by ordinary people who live close to the sea, remembering that a major portion of the whole global human population lives near seas and oceans and many of these people depend primarily on fish for sustenance. Not surprisingly coastal fish stocks have already been depleted in some areas, yet coastal human populations continue to rise.
The factors outlined above that have caused a decline of grain stocks – incremental soil nutrient depletion, bare ground agriculture, continued global human population growth, dietary change in developing countries, increased bio–fuel production and extreme weather conditions, will all continue to operate. Population, according to the UN medium variant projection will rise from around 6.6 billion in 2007 to around 9.2 billion in 2050. Dietary change will continue to take place. Biofuel production is steadily increasing, and as was mentioned earlier, the UN says that global production is likely to double in the next four years. Severe weather events, in the broad sense of that term, presently having a somewhat equivocal effect on food production as distinct from widespread destruction of houses and infrastructure, but they are predicted to increase in number and severity, and this is likely to adversely effect total land based food production. Over–fishing in marine waters will not suddenly cease. So will we be able to continue to feed the global population? We look first at the impacts of future climate change.
1) Climate Change
There is now a consensus not only that climate change is taking place, but that it is at least primarily being caused by man's activities, notably through the increased production of greenhouse gases. And it is predicted that future climate change will cause shifts of climate in various parts of the world, so that some regions become drier, some wetter.
Now in general, food crops are very sensitive to climate change (Pimentel, D., 1993, Forum for Applied Research and Public Policy volume 8). In any region of the world, future climate change may benefit some crops and harm others, and considerable adjustments may have to be made about which crops to grow where. Concern has been expressed about corn production: the enormous corn belt of the northern hemisphere is projected to become hotter and drier, and this cannot be compensated for by creating new cereal belts further north because the soils further north are different, and anyway, land is largely utilized for other purposes already (Ecobridge. http://www.ecobridge.org/content/g_tht.htm)
Severe weather events are forecast to increase both in frequency and severity, and while locally, floods may actually lead to increased food production, on balance, such severe events are likely to reduce global food production.
More generally, modelling studies indicate that in the medium to longer term, if not over the next several decades, although in some regions crop production may benefit from climate change, on balance crop yields will be affected adversely, especially in regions that are already food-insecure (McMichael, A. J., 2001, Proceedings of the Nutrition Society).
. One aspect of global warming will certainly have a devastating effect on food production — the forecasted rise of sea levels, which will inundate vast areas of low lying land across the globe, and it is the low lying regions of the world that are most agriculturally productive.
An interesting and recently reported phenomenon could have adverse effects on food production. Ozone, generated by oxides of nitrogen from vehicle exhausts and fossil–fuel burning power stations reacting with other chemicals in the air, is a minor greenhouse gas. But it can also poison plants. Climate modelling suggests that rising levels of low level ozone pollution over the coming century will erode the ability of plants to absorb carbon dioxide from the atmosphere (Hopkin, M. (2007) Nature, volume 448, 26th July).
Then consider wild fires. As we have already noted, this year has seen widespread fires in some regions of the world. Now the rising global temperatures have made an increase of wildfires inevitable and wildfires destroy forests. Apart from fire destruction, there is evidence that climate change is already having adverse effects on some forest ecosystems, such as northern conifer forests (footnote 3). These effects could lead to a vicious cycle because forests sequester CO2 so when forests are reduced, more carbon dioxide stays in the atmosphere, producing further climate change.
Fires also sometimes destroy crops. Now fire destruction of forests and crops can have an unfortunate side effect: Work by T. Hogue and J. Jay at the University of California shows that wildfires affect the quality of runoff water, and may, as has been the case in California, cause increased amounts of iron, mercury and aluminium to accumulate, affecting the quality of downstream water supplies and the rate of vegetation growth, and hence crop production.
Global warming is likely to see the spread of insect pests from the tropics and sub–tropics northwards into the temperate zone. Rising temperatures in the temperate zone will lengthen the breeding season and increase the reproductive rate of insect pests of food crops and forests. This will be aggravated with some species by the fact that low winter temperatures control numbers so rising winter temperatures will boost the over-wintering populations.
And now, there are indications that global warming may be taking place faster than previously expected (footnote 4). Worse still, there is the very real possibility that there may be a relatively sudden transition to a much more severe climate, as James Lovelock concluded in his book “The revenge of Gaia”. We write about this in our review of his book on our Book reviews page:
”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).
2) Degradation of the agricultural land base
Any possible future developments in global food production, planned or unplanned, need to be viewed in the context of the terrible degradation of the agricultural land base that has already occurred.
Since the advent of agriculture, agricultural practices have generally damaged soil structure and depleted soils of nutrients, and in modern agriculture, food production has only been maintained by the use of artificial fertilisers (Salonius, P. 2007, The Forestry Chronicle volume 83), which farmers in many poor countries cannot afford ( Salonius writes to us “agriculture has never been sustainable in the long term because it replaces complex nutrient conservative ecosystems with simplified food crop assemblages that allow nutrient leaching in excess of soil formation”). Rising energy prices associated with dwindling gas and oil reserves combined with the need for increased food production worldwide, particularly in areas like India and China, and the rapid rise in bio-fuel production, notably in Brazil and the US are likely to ensure that fertilizer prices will rise.
Nutrient depletion is made worse in those countries where, in an attempt to increase food production for a growing population, fallow periods that would have restored some fertility have been reduced or abandoned, and also made worse when dung, that would have added nutrients to the soil has instead been used as a fuel. Loss of soil structure has gone hand in hand with nutrient depletion and one consequence has been increased soil erosion.
Soil erosion has in fact been a serious problem across most regions of the world for a long time. In many drier warmer parts of the world, overgrazing leading to loss of natural cover and soil compaction has caused increased water runoff and associated soil loss, and eventually desertification. Deforestation in tropical regions has led to heavy rainfall impact on soils, an impact previously mitigated by the forest trees, causing run off of top soil. Soil erosion has been particularly serious where, in an effort to increase food production, steep hill slopes have been cleared of the natural vegetation, leading to rainfall caused soil erosion.
In many parts of the world water tables have been falling and aquifers depleted as water extraction has exceeded natural replenishment. There is in effect, a competition for water between farmers who require water for food production and the burgeoning populations of people in neighbouring urban areas who require water for all their needs. The underlying cause is the growth of the human population, and the result is that food production is threatened in many regions.
The use of irrigation to allow food production in arid areas has led to a serious problem, namely the salinisation of soil through the long term accumulation of salt ions that occur in river water. This was a major factor in the collapse thousands of years ago, of the large human population in Mesopotamia, another major factor being deforestation leading to soil erosion. In the present era, salinisation has occurred in numerous countries so that it was already a threat to the economies of some countries a decade ago or more, when in India for example, 35 per cent of irrigated land was already seriously salinised.
All this past land degradation is bound to have a limiting effect on efforts to increase global food supply. And of course, the various processes involved will continue to operate in the future.
3) Conflict
Sometimes discussions on food production seem to be conducted as if we were dealing with a nice experimental plot on a well controlled farm. Unfortunately global food production is not carried out under such circumstances! Consider conflict. It is not possible to implement programmes of food production in areas where society is riven by civil strife. Even low level strife or between group tensions can stymie food production.
There are many examples of conflict over land and water supplies in the past and the present. Population–driven scarcity may not usually be the only cause, as varied combinations of other factors are usually involved, such as loss of traditional access to natural resources and eviction from farmlands. However, in our view, rapid population growth in the last half–century has been the underlying multiplier of most land and water conflicts. Further, we think these conflicts are likely to become more prevalent and severe in the future: Up to now, globally, there have been 'safety valves' that have mitigated land and water tensions — frontier settlement, irrigation–assisted agricultural expansion and rural land reform. But for most countries, at least the first two of these possibilities are becoming exhausted. And the climate effects of global warming, already referred to, will in our view increase land and water conflicts.
There seems to be a global association between the extent that a country has progressed along the path of the 'demographic transition' (reduction in death rate followed by reduction in birth rate, leading first to the development of relatively youthful populations and later a transition to older–structured populations) and the outbreak of civil conflict (R.Cincotta et al, 2003 “The security demographic. Population and civil conflict after the cold war”. Population Action International).
Countries in the early stages of the transition are at the greatest risk of civil conflict, and the transition greatly reduces the risk. It seems clear that youthful populations tend to be politically volatile: populations with a large proportion of young people are associated with the outbreak of political violence and warfare. Now while industrial countries have completed the demographic transition, and many countries across the world are well on towards completion of the process, there are still many countries, largely in Africa, where the transition has slowed or completely stalled.
Throughout the world, there has been a trend of population movement towards urban areas, so–called urbanisation. Of course this has had positive effects, like providing employment and access to health services. But the process of urbanisation in the developing world has been like a flood, and governments have been unable to cope with the consequences, which have included exacerbation of inter–ethnic competition and conflict. Analysis of the situation suggests that those countries with the highest urban population growth rates have been about twice as likely to experience civil conflict as those countries with a lower urban growth rate (Cincotta et al, ibid). Now this process of urbanisation is set to continue in the developing world, and we think that many governments will as in the past, be unable to cope with the influx, some of the worst affected countries being in Africa.
So on the African continent, we have a combination of conflict enhancing and or causing factors: failure to complete the demographic transition, rapid urbanisation, and dwindling agricultural production potential arising from the facts of much diminished soil fertility, shortage of yet unused land for agricultural production and water shortages. And we note that the FAO report mentioned earlier, in attempting to explain why 21 countries are in crisis over crop prospects, mentions 'conflict', or 'civil strife' as being one of the causes in seven of these countries.
All this suggests to us that food production in Africa is unlikely to improve, or if it does so, not at anything like the rate it needs to do to have a really significant positive impact on global food production. If you add to all this the fact that the population of Africa is projected to grown massively, consequently creating a massive increase in demand for food, the very large numbers of people in refugee camps in Africa, and the endemic corruption in some African countries, the prospects for the future of Africa seem very gloomy. However, in focusing on Africa, we should remember conflict causing factors outlined above are not confined to that particular continent.
So far in our treatment of populations, we have ignored the ethnic and religious composition of these populations, which we now consider. When any one ethnic or religious group feels threatened by the growth of another group or groups this can lead to tensions and conflict between groups, within or between countries. Such changes in composition may be brought about through migration, but also by differences in fertility rate between ethnic groups. Throughout history population composition altering migrations have led to change or elimination of local cultural traditions, institutions and patterns of land use and control, producing what have been descried as 'volatile fault lines of ethnic confrontation'. Such tensions and conflict may impede or even prevent any coordinated efforts to produce enough food to feed the population or more generally, to achieve sustainable development.
Finally, in our view both intra- and inter-state migration is likely to increase in the future, as agricultural land continues to be degraded and diminished in area through the continuation of unsustainable agricultural practices, urban growth and climate change, often in countries already experiencing a food deficit. Continued population growth will act as the underlying multiplier of the problem. Such migration is likely to increase intra– and inter–state conflicts in the developing world, and possibly even in the developed world, making it increasingly difficult to ensure adequate food provision for human populations.
We are well aware that these portents of doom will not convince everybody that global disaster may be just round the corner. Optimists will point to the possible massive increase in food production through a thorough exploitation of the potentials of so-called 'genetically modified' crops, a curious term since all current agricultural crops have been produced by what amounts to genetical engineering! They will point to the many local schemes across the globe promoted by non-governmental organisations that are, or have the potential to, achieve sustainable development. They will point to the possibilities of taking effective action to greatly mitigate climate change and hence the effects of climate change on food production. More generally they will say that man has always coped in the past through technological change, and so there is no reason why we should not be able to cope in the future. Some will even argue that nuclear fusion energy supply will come on stream in time to largely eliminate the production of industrial greenhouse gases and so reduce global warming. However, we think that the combination of adverse factors we have rehearsed are likely to overwhelm any positive action that mankind may take in the future to continue to feed the global human population.
One thing that we think is likely to set the seal on this conclusion is the attitude of people. Our culture in the industrialised world has changed so that a hedonistic attitude and the pursuit of wealth are now all pervading. People have many concerns, but the most important issue of all, the very survival of mankind, is, for the majority, not one of them.
Globally, we think the vast majority of people just do not realise how serious the situation is, and so do not concern themselves about the issues we have discussed. And most of those people who do realise, simply shrug their shoulders and adopt the attitude — well, there is nothing I can do about it.
As regards climate change, while a few people do campaign on global warming issues and make efforts to reduce their consumption, there is no groundswell of public opinion to force governments to take effective action locally or globally, despite considerable media attention to global warming.
Further, in our view, the actions taken, and measures proposed, by governments across the world to deal with global warming, are totally inadequate. We note here that at the climate summit meeting in October the head of the UN Climate Panel said that governments may need to step up the fight against global warming to a level beyond even the toughest goals to help safeguard the planet. And it was noted that many experts reckon the 2 degrees Celsius goal, seen by the EU as a limit to avoid 'dangerous' change, is fast getting out of reach because of a rapid build-up of greenhouse gases mainly from burning fossil fuels in cars, factories and power plants. We doubt very much that the EU could even reach the 2 degree goal, let alone anything more radical.
As far as population growth is concerned, there seems to be, globally, little concern about the harmful effects of continued population growth, growth that seems to be almost universally accepted as a given, something that we cannot and for many people should not, do anything about. There is no concerted global effort to take measures that would slow population growth, not even a concerted plan to make contraceptives available throughout the developing world. This future population growth is likely, in our opinion, to prevent even the best intentioned measures to adequately increase food supply to fail.
We end with a new (October) warning from the United
Nations Environment Programme:
“The United Nations Environment Programme says that
major threats to the planet such as climate change, the
rate of extinction of species, and the challenge of feeding
a growing population are among the many that remain
unresolved, and all of them put humanity at
risk”.
Footnotes
One. There are two reasons why oil prices have risen: major energy companies have not invested in building enough refinery capacity to meet growing demand, and companies have not been able to find enough new oil fields to replace those becoming exhausted. Oil is being pumped out of the ground three times faster than it is being replaced by new oil finds, so that oil reserves discovered between 1950 and 1980 are being run down.
Two. For many years farmers of arable land in the European Union (EU) have been taking out of production between 5 and 15 per cent of their arable land, under the set–aside scheme (the scheme was initially voluntary, but it was made obligatory after the 1992 reform and set at 10%). The set–aside scheme was originally introduced to limit the production of cereals as the EU had accumulated mountains of excess grain. The new setting of set–aside rate is bad news for conservationists as set–aside areas provide a valuable haven for wildlife.
For information on the agri–environment schemes introduced under the EU Common Agricultural Policy see chapter 6 of Barker, J.F. (2000) “England in the New Millennium. Are we prepared to save our countryside”. Details of the book may be found on the “Our Publications” page of our web site.
Three. In the northern hemisphere. For example, In the Sierra Nevada mountains of California mortality rates of pine and fir measured over a 22 year period from 1983 have increased at an average rate of 3 per cent a year. And the reason seems to be lack of water either affecting the trees directly or by making it easier for bark beetles to attack the trees. Serious damage that has been recorded over two decades to huge swathes of forest in Alaska and western Canada, with satellite data showing a loss of greenness, and where there was rapid defoliation from 1995 to 2000, part of the cause at least being booming insect populations. Forests in Europe and Siberia may also be under threat.
Four. Consider North America. Global warming is already having serious effects on the North American continent and the high Arctic, with previous records being broken this year. On Melville Island researchers concluded things were changing dramatically. In July, air temperatures over 20 degrees Celsius were recorded where average July temperatures normally average 5 degrees Celsius. On hill slopes topsoil is usually kept in place by the permafrost in the ground beneath. But this year, so much of this permafrost melted that this lubricated the top soil causing it to slide down slopes, clearing everything in its path, so the landscape was torn to pieces and a major river was dammed. The scientists working there were amazed, and they concluded that if this were to occur a little further south in more inhabited parts of Canada, the effect would be catastrophic.
For the first time in recorded history, the Northwest Passage between the Atlantic and Pacific oceans have opened up, indeed for a while it was navigable without an icebreaker.
Ice records have been broken. Measured by the area over which sea ice was prominent (covering at least 15 per cent of area) this year saw minimum levels since records began in the 1970s, the previous record year being very recent, namely 2005. And in terms of actual area covered in ice, this year also showed a record low, again the previous record was in 2005.
Five. In the original essay, in the sub-section “degradation of the agricultural land base” of the “future prospects” section, while salinisation of soils was mentioned, no mention was made of falling ground water levels. This has now been rectified.
In the same sub-section, two paragraphs have been
altered. Originally we wrote:
“Nutrient depletion is made worse in those countries
where, in an attempt to increase food production for a
growing population, fallow periods that would have restored
some fertility have been reduced or abandoned, and also
made worse when dung, that would have added nutrients to
the soil has instead been used as a fuel”.
“Soil erosion has been a serious problem across the
world for a long time. In many drier warmer parts of the
world, overgrazing and soil compaction has led to increased
water runoff and associated soil loss, and eventually
desertification. Deforestation in tropical regions has led
to heavy rainfall impact on soils, an impact previously
mitigated by the forest trees, causing run off of top soil.
Soil erosion has been particularly serious where, in an
effort to increase soil production, steep hill slopes have
been cleared of the natural vegetation, leading to rainfall
caused soil erosion”.
The modified paragraphs are:
“Nutrient depletion is made worse in those
countries where, in an attempt to increase food production
for a growing population, fallow periods that would have
restored some fertility have been reduced or abandoned, and
also made worse when dung, that would have added nutrients
to the soil has instead been used as a fuel. Loss of soil
structure has gone hand in hand with nutrient depletion and
one consequence has been increased soil
erosion”.
“Soil erosion has in fact been a serious problem
across most regions of the world for a long time. In many
drier warmer parts of the world, overgrazing leading to
loss of natural cover and soil compaction has caused
increased water runoff and associated soil loss, and
eventually desertification. Deforestation in tropical
regions has led to heavy rainfall impact on soils, an
impact previously mitigated by the forest trees, causing
run off of top soil. Soil erosion has been particularly
serious where, in an effort to increase food production,
steep hill slopes have been cleared of the natural
vegetation, leading to rainfall caused soil
erosion”.
Since we originally posted this essay on the web, Peter Salonius (see our reference to a paper by him in the degradation of the agricultural land base sub-section) in correspondence with us has made some useful critical comments about this essay, with which we mainly agree. We think most important were his comments that link to what we had written when we referred to his paper: “Modern agricultural practices generally damage soil structure and deplete soils of nutrients, which then require replacement by artificial fertilisers...”. Salonius comments: “agriculture has been unsustainable since hunter gatherers began to cultivate simple food crop monocultures that allowed soil nutrient losses to groundwater and thence to the ocean much faster than these nutrients were accumulated by biological nitrogen fixation, soil and volcanic dust, and weathering of mineral in the solum”. “Our ability to side step the basic lack of sustainability of agriculture appears to be coming to an end as we face geological energy depletion during the next century”. And “I have reluctantly (as I am a farmer at heart) concluded that agriculture has never been sustainable in the long term because it replaces complex nutrient conservative ecosystems with simplified food crop assemblages that allow nutrient leaching in excess of soil formation”.
.Hence we have altered the statement we made in connection with his paper to:
“Since the advent of agriculture, agricultural practices have generally damaged soil structure and depleted soils of nutrients, and in modern agriculture, food production has only been maintained by the use of artificial fertilisers (Salonius, P. 2007, The Forestry Chronicle volume 83), which farmers in many poor countries cannot afford ( Salonius writes to us “agriculture has never been sustainable in the long term because it replaces complex nutrient conservative ecosystems with simplified food crop assemblages that allow nutrient leaching in excess of soil formation”)...”
We have, however, suggested to Peter Salonius that not all agricultural practice has in the past caused reduced food production through nutrient depletion, since in Egypt, for millennia, farmers farmed sustainably, because of the nutrient - rich silt brought down by the annual rains.