May 25, 2017

Population and food supply

Appendix C: A Blueprint for Survival.

The Blueprint occupied the entire issue of The Ecologist Vol. 2 No. 1, January 1972, in advance of the world’s first Environment Summit (the 1972 UN Conference on the Human Environment, in Stockholm).

The principal authors were Edward Goldsmith and Robert Allen, with additional help from Michael Allaby, John Davoll, and Sam Lawrence.

So great was demand for A Blueprint for Survival that it was republished in book form later that year by Penguin Books, on 14 September 1972.

Note: click on images to enlarge.

It is a common assumption that throughout the entire history of mankind, human populations have expanded whenever conditions permitted. Thus it is argued that during the 100,000 generations in which our forebears lived by food-collecting, the difficulties of keeping body and soul together were so great that populations were limited largely by crude food availability. Then with the adoption of agriculture, some 200 to 300 generations ago, the new-found sources of food permitted populations to expand, until generally-speaking, they were held down only by disease. Finally, modern public health methods, principally, greatly improved sanitation and vector control procedures permitted the phenomenal increases, which collectively are known today as the population explosion.

Yet there is now good evidence that many of the human societies living before the agricultural revolution (and a few after) were stable societies in the strict sense of the phrase: i.e. they were regulated not by starvation, disease or war but by cultural controls, which only now we are beginning to understand. Why these controls disappeared we do not know. For the time being, however, we may speculate that they were lost in the cultural changes such societies must have undergone in response to the immense ecological changes brought about by each advance and retreat of glaciation during the Pleistocene Ice Age.

Since, in a nutshell, the problem of populations and food supply is how to live within one’s ecological means, without being forced to do so by naked hunger, it is worth bearing in mind that man (like many other animals) is potentially capable of so doing. In the meantime, we are faced with the task of reducing the birth rate to compensate for the fall in the death rate, because daunting though it undoubtedly is, the alternative of satisfactorily feeding an expanding population is still more so. Nonetheless, so far attempts to reduce birth rates have been largely ineffective on a global scale and even if they were to be successful it is unlikely that they could produce significant reductions in population growth rates within the time scale required to avoid major food shortages.

It is argued that the raising of living standards will, of itself, limit population growth by offering economic incentives that are reduced, if the ratio of wage-earners to dependants within the family group is weighted too heavily in favour of dependants. Evidence of this is contradictory, although it is true that families have become smaller in Europe as levels of material prosperity have risen. However, it is not possible that this situation can be repeated throughout the world as a whole. The planet lacks the resources to permit the industrialisation that would be required and even if these were to be found, the levels of pollution generated by such a level of industrial activity would be greater than could be absorbed by the ecosphere. Even then, although the rate of increase would be reduced, populations would continue to grow.

Blueprint for Survival - Figure 4 (Appendix C)The population of Britain is growing at 0.5 percent per year, which gives it a doubling time of 138 years. While this is much lower than the world average (1.9 percent each year) each individual within an industrial society consumes far more resources and contributes far more to environmental pollution than an individual in an agrarian society [see Figure 4]. Professor Wayne Davis considers that an American has 25 times the impact on the environment as an Indian so that, worked out in terms of “Indian equivalents”, the population of the United States is equivalent to that of 5,000 million Indians. [1] Thus the problem of population is more acute in developed than in developing countries.

We must consider whether it is possible for the planet to provide food in sufficient quantities to sustain the populations that are forecast.

Food production may be increased either by extending the area under cultivation or by intensifying production on existing farmlands, or by both. Current FAO programmes concentrate on intensifying production on existing farms.

The extension of agriculture into marginal lands is expensive in terms of investment and produces only limited returns. It is more rational to direct such capital as is available into the improvement of existing farming.

Indeed, the amount of marginal land available for agriculture is severely limited and it has been estimated that if the required increases in food production were to be met from this source alone, the reserves of land would be exhausted within a decade or less. [2] Of a total land area of 32.5 billion acres estimates indicate that only 3 billion are cultivated at the present time. [3] Most of the world’s land surface is occupied by icecaps and permafrost, deserts, forests and urban and industrial areas.

Sometimes it is suggested that the remaining tropical forests, in Amazonia in particular, might be cleared to provide agricultural land. It is unlikely that such schemes could be successful, even if the resources were available to carry them out. Experience with clearing primaeval forest in Central has shown that the removal of the climax vegetation triggers an erosion process leading to desert. The process is all but irreversible for organic matter once exposed is quickly mineralised. The unstable lateritic soils of Amazonia are 70 feet thick but they would be likely to erode very quickly if they were unprotected against the equatorial climate, while this itself would certainly be affected by the removal of such a large area of forest. When Kruschev cleared the forests in Kazakhstan for agriculture he left a dust bowl of some 30 million acres, an area equivalent to the entire agricultural land are of the British Isles.

The US President’s Science Advisory Committee estimated in 1967 that the total arable and potential arable land in the world amounted to 8 billion acres. While some expansion is possible it is unlikely that the resources of capital and materials can be made available to produce more than minor increases in food production from these sources. There is little marginal land remaining for development in the Soviet Union, China, Asia or Europe and extension of farmlands in the more arid regions of the Middle East and North Africa would require new sources of fresh water for irrigation that are not available at present and will not be within the immediate future. It is possible that the United States might increase its area under cultivation from 300 to 350 million acres. [3]

In fact, it is likely that existing agricultural land will be reduced as demands for urban and industrial development with all that that implies, in terms of road, airports, railways etc. are met. Between 1882 and 1953, the total land area of the world occupied by permanent buildings has increased by 0.87 billion to 1.6 billion hectares. [2] This will be much higher if, by the year 2000, 81 percent of the population of the developed countries and 43 percent of the population of developing countries will be living in urban areas. (See Table 10.)

Blueprint for Survival - Table 10 (Appendix C)Beyond a certain point, which varies with climate and soil type, the intensification of farming causes soil deterioration and eventually erosion. This is already a problem in many of the developed countries where very intensive farming systems have been imposed. The extension of monocultural arable farming, the heavy use of artificial fertilisers, the use of heavy machinery and, in other areas, overstocking with farm animals, all contribute to deterioration in soil structures, leading to a loss in the efficiency of drainage systems and in the effectiveness with which soluble fertilisers can be used.

In this situation, irrigation can lead to problems of water-logging and/or salinity, while the over-consumption of groundwater for irrigation purposes can lead to a lowering of water tables that may compromise the future of farming. In large parts of Texas, for example, the present long drought is exacerbated by low water tables and it is possible that farming in Texas may have to be abandoned altogether.

Blueprint for Survival - Table 11 (Appendix C)The deterioration of soil structure has been observed in Britain, where stable soils and a temperate climate provide near-ideal farming conditions. In more severe climates and on poorer soils erosion is likely to appear more quickly and once it begins it could become an accelerating process. As the poorer lands fail, the pressure on the better lands will increase, so tending to encourage still
further intensification, which will damage soils more rapidly than might be anticipated. (See Table 11.)

Erosion of farmlands in some areas is associated with the spread of deserts. In 1882 the world had a total 1.1 billion hectares of desert and wasteland. In 1952 the area had increased to 2.6 billion hectares. [2] (See Table 10.)

Blueprint for Survival - Figure 5 (Appendix C)Given that demand for land must increase with population growth, and that populations are increasing exponentially, and assuming that the per capita requirement of land is 0.4 hectares for agricultural purposes and 0.08 hectares for non-agricultural poses (a low estimate), Meadows has shown that by the year 2000 the land available is likely to have decreased by 250 million hectares, while the demand will have increased by about 2.4 billion hectares, and that somewhere between 1980 and 1990 the demand for land will exceed the supply. [4]

Furthermore, if yields per acre were to double, the effect would be to add no more than 30 years to the world’s food supply. Similarly a quadrupling of yield, which no serious person would consider possible, would add only 60 years. The net demand for food, then, will double every 30 years and it can be satisfied only by doubling yield every 30 years.

Britain has one of the most intensive farming systems in the world. In the 25 years since the end of World War II very large sums of money have been invested in technological developments aimed at increasing output and reducing the requirement for labour. Nevertheless, when the effect of inflation on farm prices is taken into account, the productivity of British agriculture has increased by only 35 percent and there is good reason to suppose that in most major products, yields have now levelled off and in some they are declining.

Short of major technological breakthroughs in plant genetics and, possibly, the introduction of entirely new concepts in farming, none of which is in sight at present, it is extremely unlikely that agricultural production in Britain can achieve further significant increases. It is not possible for agriculture in developing countries to receive the heavy investments that British agriculture has received and so it is unlikely that increases in production can be achieved to match those in Britain. Even if they were, they would be insufficient, even to sustain the present inadequate dietary levels. Although the so-called ‘Green Revolution’ has produced important improvements locally, overall the world food situation shows no sign of improving, and there seems little chance of the FAO’s targets for 1985 being met.

In past years local emergencies have been alleviated by the provision of food, principally grains, from world stocks, which have been held mainly in North America. These stocks have been allowed to run down and so even this ‘cushion’ is lost.

There are definite biological reasons for the limits on food production. Plants depend on a complex mixture of inputs, many of which are beyond man’s control. Even of the principle requirements – sunlight, water and nutrients – it is only nutrient that man has succeeded in manufacturing and supplying to his crops. Fertiliser use is subject to diminishing returns beyond certain levels of application and these may be much lower in the field than controlled experiment under near-laboratory conditions would suggest.

Blueprint for Survival - Table 12 (Appendix C)Thus an 11 percent increase in the agricultural production in the United States between 1949 and 1968 was achieved with a 648 percent increase in the use of nitrogen fertiliser while Britain’s 35 percent increase required an 800 percent increase in nitrogen fertiliser consumption. The consumption of pesticides to control the effects of the ecological imbalances created by the farming system has increased also. Between 1950 and 1967 US pesticide consumption increased by 267 percent and achieved a 5 percent increase in total crop yields.

The use of agrochemicals on a large scale makes a serious contribution to the pollution of the global environment. They are biologically potent, which is why they are used, and when introduced at random into the environment they interfere with living processes. Many pesticides affect the central nervous system of man, they may interfere with hormone secretions and some are known to be carcinogenic or teratogenic. Under certain circumstances some fertilisers can be harmful to health and by forming random associations with amines present in the environment, nitrites can become nitrosamines, which are carcinogenic.

There is no way of knowing the extent to which the environmental carcinogen and mutagen loads have been increased because it is impossible to monitor all the possible interactions between pollutant and pollutant and between pollutants and substances present naturally. Pesticides that are persistent accumulate along food chains, so depressing predator populations and, in the long run, tending to encourage increases, rather than decreases, in pest populations. Organo-chlorine insecticides are particularly harmful to fish. Excess fertilisers enter water systems where they contribute to eutrophication problems. There must be an upper limit to the tolerance of the ecosphere to pollution from agriculture.

The effectiveness of pesticides is further reduced because insects, weeds and micro-organisms acquire resistance to them. Such resistance is based on hereditary characteristics in certain individuals within populations. It is transmitted genetically and so repeated application leads to a build-up of a resistant pest population by a process similar in all ways to natural selection. Throughout the world there are now some 250 species of insect pest that are immune to most insecticides. [7]

In common with most organic chemicals, pesticides are derived from petroleum and their continued production is related to the availability of petroleum or of an alternative source of raw materials, although any alternative is likely to be more expensive. All agrochemicals consume power and water in their production and the availability of cheap sources of power and plentiful supplies of water is likely to limit any increase in production.

Blueprint for Survival - Figure 6 (Appendix C)The intensification of agriculture in many areas of the third world would require much improved systems of transport to convey fertiliser, pesticides, machinery and seeds in and food out. It is doubtful whether the capital is available to develop such transport systems or the fuel to power them.

It is unrealistic to suppose that there will be increases in agricultural production adequate to meet forecast demands for food, and the notion that technological inputs can be made available that would guarantee a doubling of production by 1980 and a further doubling by 2100 is no more than fantasy. Such a thesis can be advanced only by ‘experts’ who fail to take into account basic ecological, physical and biological principles, or who are not in possession of all the relevant information.

The intensification of agriculture cannot prevent famines within the next 15 to 20 years, probably affecting parts of Asia, Africa, the Near East and Latin America. Indeed, by causing further disruption to terrestrial and marine ecosystems it must reduce the capacity of the planet to support life.

Attempts to increase the world’s protein availability from fisheries show no sign of solving the problem. The seas are experiencing serious pollution which may be undermining the phytoplankton that form the base of the marine biotic pyramid, and they may be over fished. In 1969, for the first time in a quarter of a century, total fisheries production did not increase, owing to poor catches, and this in spite of heavy capital investment by the developed countries. Fishery vessels are operating in deeper and more remote waters and owing to the high levels of investment in ships and processing plant the developed countries, which are also the major fishing nations, are irrevocably committed to increasing yields by a large factor within a very short space of time.

In their efforts to do so there is little reason to suppose that they will not so deplete fish stocks that within a decade or so the contribution of fisheries to world food supplies will reduce rather than increase. If there is a temporary increase, little of this will benefit the developing countries which, by and large, cannot afford to participate in such a heavily capitalised operation. At present less than 20 percent of the world’s total catch of sea and fresh water fish is consumed within the Third World.


1. Wayne Davis, “Four billion Americans”. The Ecologist, July 1970.
2. G. Borgstrom, Too Many, Collier-Macmillan 1970.
3. Lester Brown and Gail Fintserbusch, “Man, Food and Environment”. Environment, William W. Murdoch, editor.
4. Dennis Meadows, The Limits of Growth. Potomac Associates, 1972.
5. Michael Allaby, “The World Food Problem”. In Can Britain Survive?, edited by
E. Goldsmith. Tom Stacey, 1971.
6. Barry Commoner, “The Environmental Cost of Economic Growth”. Paper presented at Resources for the Future Forum, Washngton 1971.
7. Environment staff report, “Diminishing Returns on Pesticides”. In Can Britain Survive?, ibid.
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