Edition 2 - September 2008 (updated 9/25/08)
Bruce Sundquist

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~ ~ ~ Table of Contents ~
~ ~ ~ Abstract ~
~ ~ ~ Introduction ~
[1] ~ Limitations of Chemical Fertilizers ~
[1A] ~ Marginal Productivities of Chemical Fertilizers in Developed Countries ~
[1B] ~ Marginal Productivities of Chemical Fertilizers in Developing Countries ~
[1C] ~ Side-Effects of Chemical Fertilizers on Soil Properties ~
[1D] ~ Side-Effects of Chemical Fertilizers on Other Elements of the Global Food Production System ~
[1E] ~ Side-Effects of Chemical Fertilizers on Human Health ~
[1F] ~ Sub-Saharan Africa's Linkages Among Chemical Fertilizers, Food and Population Growth ~
[2] ~ Limitations of the Green Revolution ~
[3] ~ Limitations of Large-Scale Expansions of Irrigation Systems ~
[4] ~ Limitations of Undeveloped Arable Land Capable of Supporting Sustainable Agriculture ~
[5] ~ Limitations of Pesticides ~
[6] ~ Could Some as-yet-Unknown Development(s) Contribute Significantly to Global Food Production?
[6A] ~ Tropical Soils - the Problems and the Potential ~
[7] ~ The New Context of the Food Crisis - A World of Fewer Options and Increasing Demands ~
[7A] ~ The World's Irrigation Systems - Key Problems and Their Solutions ~
[8] ~ The Role of Government Subsidies in the Food Crisis ~
[9] ~ Solutions to the Food Crisis ~
[9A] ~ Short-term Solutions to the Food Crisis ~
[9B] ~ Long-Term Solutions to the Food Crisis ~
~ ~ ~ References ~
Reference Citation Nomenclature: A typical reference citation such as (98K3) refers to a document published in 1998 and having a lead author with a last name beginning with "K." The final digit is a running index to make sure no two references are defined by the same citation.

Go to home page of this web site Go to List of References.
Go to "Terra Preta -- An Inexpensive, if not Profitable, Solution to the Problems of Global Warming and Developing World Hunger"

~ Abstract ~
The four processes responsible for virtually all of the increases in global food supplies during the last half of the 20th century are approaching, have hit, or have exceeded, their limits. Exploiting these processes further runs increasing risks of being counterproductive. Options capable of continuing the food-supply trends of the last half of the 20th century for more than a few decades into the 21st century do not appear to exist. Yet the need for such options is clear, due to:

Options exist for significantly increasing food productivities. However virtually all short-term options involve decreases in food-related subsidies and increases in the costs of food production. Most developing nations would find the resultant food price increases politically unacceptable if not unaffordable. A more politically viable, short-term, though temporary, solution would be to abolish the conversion of biomass into bio-fuels (with the possible exception of sugar). A recent secret World Bank study has found that 75% of the increases in food prices over the past few years are attributable to the reallocation of food crops to bio-fuels. Eliminating this reallocation could postpone the food crisis by some unknown number of years.

The most successful long-term, but more permanent, strategy for dealing with the issues bulleted above is to significantly reduce the extreme scarcity of financial capital in developing nations in order to make currently unacceptable strategies viable. A growing number of nations have accomplished this, and have evolved from developing-world status to (or close to) developed-world status. They all did this during periods characterized by the use of active family planning programs that eliminated the underlying cause of the capital scarcity the need to expand infrastructural capital that population growth calls for. This strategy is becoming increasingly popular as the underlying cause of capital scarcity (and the instabilities this scarcity causes) becomes more apparent. Also the cost of such a strategy has dropped by several orders of magnitude in recent decades as a result of new, low-cost technologies for averting births.

A promising, but yet to be fully developed strategy is that of converting the typically low-fertility soils of tropical croplands to high fertility "terra preta" soils. The details of this issue are found elsewhere in this website. One of the significant side effects of this strategy is its potential for eliminating global warming far more efficiently than any other known strategy as described elsewhere in this website.

~ Introduction ~
The more-than-doubling of food supplies, the 40% decrease in food prices in the global marketplace, and the 24% increase in per-capita food supplies (consumption) since 1961 came about almost entirely from four developments:

These four developments have served to largely conceal the degradation of all the major components of the developing world's system for producing food and freshwater- croplands, grasslands, irrigated lands, fisheries, and surface/ ground waters. These concealment processes cannot continue indefinitely because these four developments have limitations:

Despite these limitations, degradation processes, and lack of sustainability of outputs, cornucopian writers (67K1) (81S3) (87W4) (01L1) (98D1) (03B2) of recent decades have made much use of the above-mentioned four developments and have ignored the associated limitations. They implicitly, or explicitly, extrapolated the above-mentioned trends in food prices and per-capita food supplies since 1961 out to the middle of the 21st century as proof that the potentials of global food supply systems exceed any projected human population. The folly of such an extrapolation can be seen in the fact that grain yields (production per unit area of cropland) increased half as fast in the 1990s as in the 1960s (08B3). This trend can be attributed to at least three processes: (1) Declining marginal productivities of chemical fertilizers reflecting von Liebig's "Law of the Minimum," (described below) and constraints on chemical fertilizer dose rates due to adverse effects on soil chemistry (described below); (2) Saturation in the percent of the world's grain lands that have been converted to miracle strains of wheat, rice and corn, and (3) The green revolution hitting up against its theoretical limits (described below). The most influential cornucopian, Julian Simon (81S3), has even argued that the Earth's carrying capacity is ultimately greater that the current human population by several orders of magnitude. This is based on his contention that the only real limit to food production is the amounts of human "brain-power" being applied to the issue. It should be noted however that Simon had links with the Vatican, an entity that has reminded all the world's governments that any suggestion of (or data indicative of) a limit on the Earth's carrying capacity is morally wrong. Thus Simon had little or no choice in the conclusion of his analysis. Below the above-mentioned limitations on global food supplies are examined in greater detail. Also taken up is the question of whether other, as yet unknown, processes (with the required potential for food-production increases) may be "waiting in the wings."

[1] ~ Limitations of Chemical Fertilizers ~
Early in the 20th century Haber (in Germany) developed a process that draws chemically inert nitrogen from the air and converts it into a chemical form usable by plants. Natural gas is used both as a feedstock and as a fuel for this process. World War II delayed the industrial-scale development of the Haber-Bosch process until the late 1940s, when low-cost "chemical" (inorganic) fertilizers were able to replace animal manure, crop residues, and assorted organic waste products. Use of chemical fertilizers expanded 600% during the first 30 post-WWII years. It was the single most important factor in cropland productivity growth. It made the "Green Revolution" possible. It also enhanced the economics of irrigation sufficiently to cause the rapid creation of large-scale irrigation projects during much of the second half of the 20th century. These three developments were largely responsible for the doubling or tripling of the global rate of production of food during the last four decades of the 20th century.

One-third of the global increase in cereal production during the 1970s and 1980s has been attributed to increases in chemical fertilizer consumption (03B3). (This is not even counting the role of chemical fertilizers in the Green Revolution and in the development of large-scale irrigation projects.) The Haber-Bosch process made it possible for the world's population to grow from 0.5 billion to 6.5 billion today (00S2), (01F1). It could also be argued that if Haber's process had been developed earlier (i.e. if the US had supplied Germany with the necessary natural gas), most or all of the economic wretchedness and social-, political- and military tumult of the first half of the 20th century might have been avoided. That half-century was, after all, a period when contraceptives and abortion were usually outlawed, population growth was rapid, and agricultural productivity was relatively low.

One should not infer, however, that global cropland productivity can be increased indefinitely simply by applying ever-increasing doses of chemical fertilizers to the world's croplands. The main reasons for the limitations of chemical fertilizers are:

[1A] ~ Marginal Productivities of Chemical Fertilizers in Developed Nations ~
In the mid-19th century, Justus von Liebig formulated his "Law of the Minimum" (76J1) that states that plant growth is limited primarily by the availability of whatever plant need is scarcest. This means that (1) plant growth is most strongly influenced by changes in the supply of the plant need that is scarcest and (2) the marginal productivity of any plant requirement (water, sunlight, or nutrients) decreases with increasing dose of that requirement. This explains, for example, why chemical fertilizers are more effective in irrigated croplands than elsewhere. The marginal productivity of chemical fertilizer in the developed world is now a fraction of what it was some decades ago (91B1) (Ref. 71 of (97B3)). US farmers have discovered that there are optimal levels beyond which further applications of fertilizer are not cost-effective, and so are using less fertilizer in the mid-1990s than in the early 1980s. As natural gas prices increase, the point of zero marginal productivity occurs at lower doses. (Chemical fertilizer uses natural gas both as a feedstock and as the source of energy. This helps to explain why "fertilizer energy" is 28% of the energy used in agriculture (00H1).) This trend in marginal productivities is also evident in Western Europe and in Japan (Ref. 71 of Ref. (97B3)). Some data on declining marginal productivities are given below.

Chemical fertilizer consumption dropped 23% during 1988-1998 (98P2) due to elimination of fertilizer subsidies in India, China and the former USSR (94B4). If the marginal productivity of chemical fertilizers had been able to cover their marginal costs, it seems unlikely that elimination of government subsidies would have resulted in reduced consumption, or that subsidies would have been deemed necessary in the first place. This would suggest that the marginal productivity of chemical fertilizers had fallen in these nations to the point where chemical fertilizers were not worth the unsubsidized price.

Europeans use significantly higher dose rates of chemical fertilizers than the rest of the world. Some people tend to interpret this as meaning that the rest of the developed world could greatly increase food production simply by increasing their dose rates of chemical fertilizers up to European levels. This is not so. Chemical fertilizers in high doses can severely damage temperate soils (as discussed below). However this damage can be eliminated by also applying heavy doses of organic fertilizers (animal manure). This option is no longer available to the remainder of the developed world for reasons discussed below. Sewage sludge might offer an alternative to animal manure but, in most urban sewage systems, avoiding toxic industrial chemicals and excessive amounts of heavy metals can be difficult and expensive. However this option cannot be ruled out if precautions are taken.

[1B] ~ Marginal Productivities of Chemical Fertilizers in Developing Nations ~
If the marginal productivity of chemical fertilizers has fallen to, or nearly to, the point of zero marginal returns in the developed world, one must not extend this conclusion to the developing world without closer examination. Chemical fertilizer consumption per unit area of cropland in 1997 in developed countries was about 40% more than in developing countries (00W1). But the heavy usage of chemical fertilizers in the developed world comes, in part, from heavy European subsidies for chemical fertilizer consumption (98D1) and doses of animal manure that the rest of the world could not match. Also, much of the consumption of chemical fertilizer is closely tied to use on "Green Revolution" crops. These were developed especially to make them amenable to higher doses of chemical fertilizer. In the developing world "Green Revolution" crops are limited to high base-status soil areas of tropical Asia and tropical America (18% of the tropics -- areas that are already intensively exploited (75S1)). So, even under optimal conditions, chemical fertilizer consumption per unit area of cropland in developing nations must be inherently less than in the developed world. Thus one should not infer that lower fertilizer consumption in developing nations means there is lots of potential for increasing chemical fertilizer consumption in developing nations.

A major difference between the developed and the developing world is that the latter is mainly in tropical climates. In tropical climates, soil organic matter contents of soils tend to be about a third of those in temperate soil for reasons that are described later in this document. As a result, temperate soils tend to be more fertile than tropical soils. Nutrients like those in chemical fertilizers need to attach to soil organic matter or they tend to be leached away into the ground waters without providing much benefit to crops. As a result, the benefits of a given dose of chemical fertilizer in tropical soils tends to be less than in temperate soils. This means that the marginal productivities of chemical fertilizers applied to tropical soils tend to be less than in temperate soils. This makes the economics of chemical fertilizers in tropical soils inherently less than in temperate soils. Under such conditions it is little wonder that the developing world's rate of consumption of chemical fertilizers is less than in the developed world.

For all of the above reasons, one should not assume that the fact that the developed world consumes 40% more chemical fertilizer per unit area of cropland than the developing world means that there is still plenty of room for developing nations to improve their cropland productivities simply by adding more chemical fertilizer. Whatever the remaining justifiable percentage increase in inorganic fertilizer consumption in the developing world is (if any), the percentage increase in food production to be expected from this extra fertilizer must be far less. This simply reflects the law of diminishing marginal returns and von Liebig's "Law of the Minimum." The conclusion from all of this is that it is far from clear that the developing world has more potential for adding more chemical fertilizer. The obvious exception to this is sub-Saharan Africa. They use very little chemical fertilizer. Therefore they have lots of potential for increasing chemical fertilizer consumption as Borlaug and others have pointed out (02K1) (90L1). The problem is that sub-Saharan Africans cannot afford it (08S1), for reasons discussed below.

[1C] ~ Side Effects of Chemical Fertilizers on Soil Properties ~
Some previously unanticipated (and damaging) side effects of chemical fertilizers are now being more broadly recognized. These show that simply adding more and more chemical fertilizer to cropland under conditions of low marginal productivity and increasing feed stock prices is increasingly unlikely to be economically justifiable, and could easily prove to be counterproductive.

Results similar to those found in Ref. (99U2) (See above) have been found in more extensive studies (07K1). It was once believed that chemical nitrogen fertilizers sequester soil organic carbon by increasing the input of crop residues. This perception is shown to be false, and the opposite is found to be true. After 40 years of synthetic (chemical) fertilization in which inputs of fertilizer nitrogen exceed grain (crop) nitrogen removal by 60 to 190%, a net decline occurred in soil organic carbon despite large amounts of residual organic carbon being incorporated into the soil (07K1). These findings implicate chemical (fertilizer) nitrogen in promoting the decomposition of crop residues and soil organic matter. The results are consistent with data from numerous cropping experiments involving synthetic nitrogen fertilization in the US Corn Belt and elsewhere (07K1).

Despite the use of forage legumes, many Midwestern US cropland soils had suffered serious declines in both nitrogen content and soil organic matter by 1950, except in cases involving regular applications of manure. There are good reasons for being concerned that these declines could adversely affect both agricultural productivity and sustainability of cropland productivity because soil organic matter plays such a key role in soil properties generally (See below). Numerous 15N-tracer studies have found that the nitrogen found in grain (crops) originates largely from soil nitrogen (the nitrogen stored in soil organic matter) rather than from the nitrogen supplied by chemical fertilizers (07K1). This means that the positive effects of chemical nitrogen fertilizers must ultimately be totally counteracted by the effects of chemical nitrogen fertilizers in reducing soil organic matter. (Note: People who are unaware of the extreme importance of soil organic matter in determining the productivity of cropland soils ((66K1), p. 228) should review the list of benefits given in Section [B5] of Reference (08S1).

[1D] ~ Side Effects of Chemical Fertilizers on Other Elements of the Global Food Production System ~

The common practice of applying chemical fertilizer nitrogen in ever increasing excesses relative to crop (grain) nitrogen also carries serious implications for atmospheric CO2 enrichment because soils represent the Earth's major surface-carbon reservoir. Chemical fertilizers speed up the mineralization of soil organic carbon to produce atmospheric CO2 and this does double damage: (1) depleting soil organic matter and (2) increasing atmospheric CO2. Also, application of chemical fertilizers beyond crop nitrogen requirements contributes to anthropogenic production of N2O, a potent greenhouse gas, and a gas with adverse implications for stratospheric ozone. In addition, excessive chemical fertilizer nitrogen promotes NO3- pollution of surface water and ground water (07K1). Excessive chemical fertilizer nitrogen applications can be reduced or eliminated by extensive use of forage legumes and applications of livestock manure (as is done in "mixed agriculture" in Europe and Wisconsin) (07K1). ("Mixed agriculture" commonly refers to farms that produce both livestock and crops. This form of agriculture is most commonly practiced on smaller farms and is probably the most sustainable form of agriculture.)

[1E] ~ Side Effects of Chemical Fertilizers on Human Health ~
Excess chemical fertilizer runoffs also produce high concentrations of nitrates in surface- and ground water supplies. These nitrates harm human health (cancer, "blue-baby" syndrome and other illnesses) (99U2). Note that both organic and chemical fertilizers contribute to nitrates in surface- and groundwater supplies. Thus is why nitrate levels in surface and ground waters in large areas of the EU often approach or exceed legal limits (50 ppm) based on human health considerations (03N1). Since the 1970s extensive leaching of nitrate from soils into surface water and groundwater has become a public health issue in almost all industrial countries (01O1) (04T1).

[1F] ~ Sub-Saharan Africa's linkages among Chemical Fertilizers, Food, and Population Growth ~


  1. Africa has some of the world's worst (oldest) soils- geologically - and the most hunger.
  2. Africa has the world's highest population growth rate.
  3. Africans uses less chemical fertilizer per unit area of cropland than any other continent. This results, essentially, in the mining of essential soil nutrients.
  4. Africans often use livestock manure and crop residues as fuel for cooking, depriving their cropland soils of organic matter.
  5. Africa, despite its high potential, makes little use of irrigation, primarily due to financial capital scarcity and staggering external debts.
  6. Africa's extremely high external debts make financial capital and human capital scarce.
  7. Africa is the only continent where per-capita food production is falling.
  8. Africa has the world's second-highest number of on-going armed conflicts, further depleting its financial capital.

Considerations (3) through (8) are easily traced back to Considerations (1) and (2) above (08S2). Thus the sustainability of Africa's food- and wood-production systems is almost certainly the world's worst. One must be careful, however, not to conclude that Africa is necessarily over-populated. If Africa's population growth rates (not population) could be reduced, Considerations (3) through (7) would be far simpler to deal with as a result of financial capital becoming far less scarce (08S2). (The extreme scarcity of financial capital can be traced to the demands on such capital to finance the growth in infrastructure that population growth calls for (08S2). The 1.3%/ year average rate of population growth for the developing world calls for an annual investment of about $1.2 trillion in infrastructure growth.)

Sub-Saharan Africa provides an insightful case study for any analysis of the undeveloped potential of inorganic (chemical) fertilizer. African soils are, by geology (few volcanoes and no ice ages) and by climate (tropical), poor in terms of both organic matter and chemical nutrients. Yet, in the 1990s, inorganic fertilizer consumption in China was 240 kg./ ha/ year, 110 in India, but about 8 in Sub-Saharan Africa. This helps to explain why cereal yields in sub-Saharan Africa are barely 100 tonnes/ km2 (vs. over 300 in Asia) (08F1). Another reason is the deep red color of (sub-Saharan) Africa's soils that means that they are rich in iron that renders phosphorous unavailable to plants (08F1). Some Sub-Saharan African cropland soils have nutrient losses exceeding 60 kg/ ha/ year of nitrogen, phosphorus and potassium (02F1). So the region would appear to be a prime candidate for increasing chemical fertilizer consumption. Inorganic fertilizer prices in Sub-Saharan Africa are 6 times greater than in Asia, the EU and North America. (On the basis of hours of labor required to purchase a tonne of inorganic fertilizer, the cost to Africans is 60 times that in the EU.) Infrastructure (mainly roads) is the cause of much of the price problem. An entrepreneur in Central Africa pays more than 3 times what his Chinese counterpart pays to transport a container a given distance (06W1). Much of Africa has less than 10% of the road density of India or China (02F1) and road quality is low. These infrastructure problems result from a shortage of financial capital that are due to Sub-Saharan Africa's high population growth rates (2.5%/ year - the highest in the world).

Sub-Saharan African cropland soils (like most tropical soils) are also poor in organic matter, but farmers cannot raise much livestock (manure source) because of population pressures on the land. Also, instead of putting manure and crop residues into cropland soils, Africans must burn them for fuel and cooking whenever wood is scarce. Wood scarcity is frequently a consequence of population pressures on the land (02F1). For these reasons, low soil organic matter contents worsen the economics of inorganic (chemical) fertilizer consumption and hence the economics of irrigation (02F1). The basic chemistry of these issues is summarized in Section [6A] below.

So, in theory, there is untapped potential for inorganic (chemical) fertilizers in Sub-Saharan Africa. The financial capital needed for building transportation infrastructure that could make imported chemical fertilizer affordable is but one of many unfilled needs for financial capital. According to Norman E. Borlaug of Green Revolution fame, Africa's grain productivity could be doubled or tripled in three years (02K1). Higgins and Kassam (Ref. 20 of Ref. (90L1)) estimated that soils of tropical Africa, if properly used, and at low levels of (nutrient) inputs, could feed 3 times the 1975 African population, and 1.5 times the estimated population in 2000. At intermediate levels of (nutrient) input, Africa could feed 5 times the population projected for 2000 (90L1). These people apparently ignore the fact that the chemical fertilizer required for this to happen is impossible to afford until population growth rates drop. This drop would reduce the financial capital required for the infrastructure growth that population growth calls for. This then creates the financial capital needed to build better transportation infrastructure and other items of infrastructure (e.g. banking systems for loaning financial capital to farmers).

Africa's present food deficit, plus its expected population doubling over the next 3-4 decades, demands at least a tripling of grain production. One third of the 590 million people in Sub-Saharan Africa are chronically under-nourished. Foreign food donations, even today, cover only 20% of Africa's food deficits (02K1). The rapidly increasing price of grain due to increases in fossil fuel prices and reallocation of cropland to crops for "biofuels" are dramatically increasing the price Africans and others must pay for food imports. The World Bank has warned of possible food riots in Africa - riots that have since occurred. Sub-Saharan Africa's ever-growing external debt and its extreme shortage of financial capital essential for solving infrastructure problems suggest that comments by Borlaug, Higgins and Kassam (and even the FAO's projections (03B3) out to 2030 of a 61% increase in food production) on Sub-Saharan Africa's future grain production are likely to remain wishful thinking until more fundamental problems are (1) recognized and (2) solved. If chemical fertilizer prices in the US were to rise by a factor of 60 to be comparable to the situation in sub-Saharan Africa, it seems likely that US consumption of chemical fertilizers would drop significantly in order to rebalance marginal costs against marginal productivities. Hunger in the US would almost certainly increase significantly as a result.

Go to home page of this web site Go to List of References.
Go to "Terra Preta -- An Inexpensive, if not Profitable, Solution to the Problems of Global Warming and Developing World Hunger"

[2] ~ Limitations of the Green Revolution ~
The question here is whether further improvements in the genetic makeup of cereal grains (like those that occurred during the "Green Revolution") could provide additional increases in global food production that are significant relative to the seven demands listed in the bulleted list in the Abstract. Below are arguments contending that the answer is No.

Plant breeders have never been able to fundamentally alter the basic process of photosynthesis itself, i.e. to produce more plant mass without added water, fertilizer, etc. (97B3). Instead, the "Green Revolution" contributed to global food production by increasing the "Harvest Index," the fraction of plant photosynthate devoted to seed development (i.e. grain - roughly 80% of the food people eat). The "Harvest Index" for originally domesticated species of wheat was around 20%. The "Green Revolution" increased the Harvest Index for wheat, rice and corn to over 50%. Scientists see a physiological upper limit to the "Harvest Index" of around 60% (97B3) (93E1) or less (99M1). This suggests that further major improvements to global food supplies via genetic improvements are unlikely. This belief is supported by the fact that, after over 20 years of research, bio-technologists have not produced a single high-yield variety of wheat, rice or corn (97B3). Maximum rice yields have been the same for 30 years. Still, official projections from the World Bank, FAO, and IFPRI assume agricultural researchers can repeat the Green Revolution (99M1). This would require a Harvest Index of over 100% (far beyond the theoretical limit), or fundamentally altering the basic process of photosynthesis (something no one has ever done, despite the very low efficiency of the photosynthesis process in utilizing the radiant energy of the sun.)

Weighing against whatever small potential for genetic improvements still exist are the negative side effects that are likely to decrease the probability of future genetic improvements. The number of varieties of food grains in common use is shrinking as a result of planting ever fewer genetically improved grain species. Reducing biodiversity increases vulnerability to pests. Also, modern farmers are now planting huge monocultures instead of practicing strip-cropping and crop rotation. This gives pests an even greater advantage. Since 1900, 75% of the genetic diversity of domestic agricultural crops has been lost (98H1). Without constant infusions of new genes, geneticists cannot continue to improve crops. Cultivars need to be reinvigorated about every decade in order to protect them against genetically improved pests that keep adapting by a process of natural selection to the changing genetic make-up of crops (98H1). The most effective way to do this is to interbreed domestic plant varieties with wild ones (98H1). This may explain why, despite major increases in pesticide-use in recent decades (both in terms of tonnage and in toxicity per ton), losses to pests have not decreased. Other reasons include an ever-increasing rate of introduction of exotic pest species as (a result of globalization of the world's economies), mono-cropping, and other ill-advised agricultural practices that largely reflect growing population pressures upon the land. The overall trend in genetics research for the past several decades appears to be away from high-yield species. The focus is shifting to damage control - developing new plant species with improved pest-resistances to replace previously developed plant species that have lost, or are losing, their resistance to genetically improved pests that keep evolving through natural selection.

The "genetically modified" crops one hears about during the past decade or two are mainly developments to increase pest-resistance. These "modifications" were developed to counteract the genetic adaptations of pests to enable them to consume those "pest-resistant" plant species developed a decade or so earlier. So all that present-day "genetically modified" plants do is to keep one step ahead of "genetically modified" pests. Losses to pests have not decreased for some decades. This suggests that expecting significant improvements in productivity from "genetically modified" plants is likely to produce mainly disappointment. The objective now is to hang onto current productivities rather than advance the "Harvest Index" - the approach taken in the 1940s and 1950s when all those "miracle strains" of cereal grains were developed. There is no reason to believe this will ever change.

If researchers cannot develop genetically improved cereal grains of the sorts developed back in the "Green Revolution" days of the 1940s and 1950s, perhaps they can expand the range of existing genetically improved cereal grains. Below we argue that this, too, is unlikely in all but a few instances.

Some undeveloped potential for genetic improvements to increase cereal grain productivity lies in the fact that not all grain crops now growing in developing nations are genetically improved. Across all developing countries, modern rice varieties were being grown on 74% of the planted area in 1991, modern wheat on 74% in 1994 ((98M2), p. 220 and about 70% of the world's corn in the early 1990s (00R1). Overall, it was estimated that 40% of all farmers in the developing world were using Green Revolution seeds by the early 1990s, with the greatest use found in Asia, followed by Latin America (00R1). Today's numbers would be expected to be significantly higher. However, most high-yield seed varieties of wheat, corn and rice developed by Borlaug et al during the "Green Revolution" are inapplicable for large areas of the developing world because of adverse soil conditions such as build-up of salts, iron- or aluminum excesses, or high acidity (82B1). The spread of the Green Revolution is limited to high base-status soil areas of tropical Asia and Tropical America. High base-status soils (18% of tropical soils) are already intensively exploited and have been so for some decades (75S1). It would seem, therefore, that high-yielding, fertilizer-responsive crop varieties are planted on nearly croplands that are suitable (91B1).

Also note that the basic concept behind the "Green Revolution" is to make plants better able to utilize chemical fertilizers (energy) and organic fertilizers. (The Green Revolution increased the energy flow to agriculture by an average of 50 times the energy input of traditional agriculture (94G2) making modern agriculture influenced to a far greater extent by the price of fossil fuels.) In Africa, very little chemical fertilizer or organic fertilizer is used, so the Green Revolution is barely applicable to Africa. The reason why chemical fertilizers are so little used in Africa is because they cost 60 times more than they cost in the European Union (in units of hours of labor per tonne of chemical fertilizer). This is due mainly to the fact that Africa has a very poor transportation infrastructure. This, in turn, is due to Africa's high population growth rates, placing huge financial demands on the infrastructure growth needed to accommodate that population growth. In a region where the median earning is less that $2/ person/ day (00S1), this makes financial capital extremely scarce, thus Africa's bad transportation infrastructure (in terms of both miles of roads and quality of roads.) The reason why so little organic fertilizer is used on Africa's croplands is that the manure from livestock and crop residues must be used as fuel for cooking food, since fossil fuels are such an expensive luxury. The result of all this is that Africa's farmers are "mining" the nutrients like nitrogen, potassium and phosphorous from their cropland soils. This is certain to diminish the productivity of Africa's croplands over time. So if any small increases do occur in the extent of utilization of genetically improved crops, these increases are likely to be counteracted by the increasing poverty of Africa's soils - soils that were of very low quality even long before Man set foot in Africa. (Australia's soils are also very poor because they are very old, i.e. there weren't any ice ages or significant volcanic activity to renew them.)

The miracle that has fed us for a whole generation now was the "Green Revolution:" higher-yielding crops that enabled us to almost triple world food production between 1950-90 while increasing the area of farmland by no more than 10%. The global population more than doubled in that time, so we now live on less than half the land per person than our grandparents needed. That one-time miracle is over. Since the beginning of the 1990s, crop yields (per unit area) have essentially stopped rising (06D1). There remain opportunities for developing grains better suited to the soils and climate of specific regions of the earth. This has happened in recent years in West Africa and central Brazil. But the global impact of such developments is not likely to be significant, and the productivity increases are likely to be consumed in a matter of a few decades or less by population growth in the local region.

Thus the question of whether the "Green Revolution" has yet to peak, has peaked, or has become counter-productive at its margins remains open. But it seems clear that the era of rapid productivity growth via genetic improvements is over, and has been over for at least several decades. The "Harvest Index" has hit up against its theoretical limit, or has come very close to it. To improve yields (production per unit area) in order to accommodate the 50% population growth expected by 2050 and compensate for the loss of croplands to urbanization, erosion, salinization, water-logging and other forms of degradation (total: about 0.1 million km2 out of a total global cropland inventory of about 15 million km2), other processes will have to be found.

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[3] ~ Limitations of Large-Scale Expansion of Irrigation Systems ~
Irrigation expansion contributed over 50% of the increase in global food production during 1965-1985 (96G2). About 60% of the food people eat comes from the world's irrigated croplands (in dollar terms). During the last half of the twentieth century, world irrigated area nearly tripled, expanding from 940,000 km2 in 1950 to 2.76 million km2 in 2000. However in the years since 2000 there has been little, if any, growth in world irrigated area (08E1). The growth in numbers of dams, worldwide, has also slowed dramatically and this trend is expected to continue. Global dam-backwater storage per-capita is expected to decrease by 2%/ year in coming decades - even as per-capita water consumption rises twice as fast as the world's population growth rate (98S1). One might argue that this merely reflects declining food prices. If food prices were to trend upward it would seem likely that irrigation system expansion should reflect the changing economics. However the situation is far more complex. The developing world (where growth in demand for food is likely to be greatest in coming decades) had engaged in massive borrowing from external sources to construct its irrigation systems. These developing world governments cannot (or do not) charge irrigators for water supplied as a means of financing loan repayments to these external sources. In fact, the trend virtually worldwide is for governments to subsidize 80-90% of the cost to taxpayers of supplying water to irrigators (07S4). As a result, increasing food prices means nothing in terms of the developing world's ability to repay irrigation-related loans.

There are also serious problems with water supply systems for irrigation systems. The International Water Management Institute, a CGIAR laboratory in Sri Lanka, projects that by 2025 as many as 39 countries - including northern China, eastern India, and much of Africa -will be forced to reduce irrigated area, rather than expand it, due to a lack of freshwater (99M1). The UN FAO said that two-thirds of the world's population could be threatened by freshwater shortages by 2025. Today, 1.2 billion people live in areas with insufficient supplies of freshwater. An additional 0.5 billion people could soon face shortages. (07F1). More than half the world's people live in countries where groundwater tables are falling (07B1). About 70% of water consumption by people goes to irrigation. Urban and industrial consumers of water can easily force the reallocation of water from irrigation systems to their own needs. So the probability of future reductions in irrigated area is significant. The worldwide shrinkage of glaciers (believed to reflect global warming) is expected to jeopardize the continuity of flows of the water supplies of 50% of the world's population (06H1). All this suggests that the future of irrigation is more likely to see shrinkage of the world's irrigated cropland area than to see another tripling of global irrigated area like the one that occurred during the last half of the 20th century.

The future of mankind is threatened to a greater degree by another irrigation problem than by growing water shortages. Most of us know the fate of the irrigation systems of centuries past. They turned into salt flats that still glisten in the sun in lands of past civilizations. Some of us even know that the same fate has met modern-day irrigation systems created only a matter of some tens of decades ago. The crucial question then arises as to what percentage of the world's currently irrigated croplands is at risk of meeting this same end. The only answer to that question this author could find during the past few decades of review of the irrigation literature is the following: "The major problems of irrigation system development and operation are not technical, but relate to the socio-political situation (74F1)." The author of that statement (a hydrologist) was reasonable certain that most, if not all, the irrigation projects he designed are destined meet the same fate as the irrigation systems of centuries past. In operational terms he is saying is that very few present-day irrigation systems are designed with protection against salt build-up (salinization), i.e. with systems of underground drainage tiles to: (1) carry off the salt that accumulates in the soil as irrigation water evaporates, and (2) prevent the water table with its salt load, from rising up to the root-zones of the plants being irrigated (water-logging). (Only irrigation systems in monsoon climates do not need this safety feature.) Even the World Bank (which is dominated by the US) does not require drainage tiles in the irrigation systems it finances (95J1). Nor does the World Bank require water conservation measures such as micro- or drip-irrigation to be installed in the systems it finances. Despite the newness of the overwhelming bulk of the world's active irrigation systems, more than 50% of the world's irrigated soils are affected by salinization, alkalization, or water-logging (Refs. 355, 356, p. 207 of Ref. (88S1)) (UN FAO and UNESCO data). The threat is greater in developing nations because they lack the financial capital required to: (1) invest in the drainage systems required to prevent salinization and water-logging, or (2) invest in drip- or micro-irrigation systems that are reasonably immune from salinization or water-logging or (3) build new irrigation systems or (4) afford the water needed to restore degraded or abandoned irrigation systems.

[4] ~ Limitations of Undeveloped Arable Land Capable of Supporting Sustainable Agriculture ~
This issue is discussed in much detail in Section [D] of Ref. (08S1). A compelling body of evidence supports the contention that the world's reserves of undeveloped arable land capable of supporting sustainable agriculture are negligible for all practical purposes. In fact, these reserves are effectively negative as a result of increasing amounts of land unsuitable for sustainable cropping being converted to croplands. Some examples of this are:

(1) ~ Semi-arid lands (that should usually remain as grazing lands) are being converted to croplands. This creates high risks of wind erosion ("dust bowls"). Some results of this are easily seen in the data on the high and rapidly increasing frequency of massive dust storms that blow vast clouds of dust across the world's oceans to distant continents, e.g. from eastern Asia (usually China) eastward across the Pacific Ocean to the west coast of North America, and from sub Sahelian Africa westward across the Atlantic Ocean to Latin America.

(2) ~ Steep, rocky hillsides of the developing world are increasingly being converted to croplands. High rates of soil erosion in such situations make cropland agriculture highly non-sustainable in all but a few developing world environments. Typical erosion rates can totally deplete the soil on a hillside in a few decades.

(3) ~ Increasing populations of shifting cultivators on tropical forests are degrading the soils of these forests. The world's population of shifting cultivators (even several decades ago) greatly exceeds the carrying capacity (no more than 10 people per square km) of tropical forest land used for shifting cultivation. One result is fallow periods far shorter than what is required to restore the soil nutrients, e.g. 3-10 years of fallow in situations where 20 years are typically required (after cropping for 2-3 years).

(4) ~ Huge numbers of desperately poor, landless, peasants in Latin America are overrunning estates of large landowners. In decades past this resulted in much bloodshed, with private militias being required to protect the interests of large landowners. More recently, populations of landless peasants have gotten so large that large landowners are being overwhelmed, and wealth is changing to ruin (04C1). Landless peasants, on the other hand, lack the financial capital needed to operate a financially viable farm and compete with capital-intensive, highly mechanized farms.

(5) ~ The Latin American situation is made even worse as a result of vast areas of tropical rainforests being converted to grazing lands devoted to producing beef for export to developed nations. Such grazing lands require only a tiny fraction of the labor inputs (per unit area) required by low-capital-intensity croplands. Tropical grazing lands can be grazed only for only 7-10 years before productivity becomes essentially zero and a prolonged fallow (20 years?) is needed to restore productivity. The benefits of converting rainforest to rangelands producing beef for export tend not to get passed down to local folk. They tend to lose access to land they once could have used for producing for local consumption. Also they wind up consuming even less meat than before the advent of vast areas of tropical grazing lands (83N1).

The most significant result of the effective depletion of the world's supply of undeveloped arable lands is what is probably the largest human migration in human history - the rural-to-urban migration. In some instances the driving force for this migration is greater economic opportunities in urban areas of some developing nations. In most instances, however, the driving force for the mass rural-to-urban migration comes from the following three on-going processes:

In developing nations, rural-to-urban migrations on a massive scale typically entail migration from rural (i.e. agricultural) areas to the wretched slums ringing most of the large urban areas of the developing world. There the typical migrant becomes part of the "informal economy" (08S3) and all the wretchedness, instability, and hope-deprivation that entails. No one is likely to do this unless his or her rural lifestyle entails an environment that is significantly worse. The three processes bulleted above explain this worsening.

The capital intensiveness of developed nations' agriculture also increased greatly, but perhaps a century or two earlier. Then the environment was far different (e.g. lots of undeveloped land), enabling developed nations to undergo the rural-to-urban migration more gradually and with far less pain. The current mass migration in the developing world often includes a stopover in the form of attempts to farm previously undeveloped steep, rocky hillsides. Unfortunately there is little, if any, hope of conducting agriculture in such an environment in a sustainable fashion. As a result, such stopovers typically last for only a few decades.

Informal economies have been around for countless decades. What is different today is the huge scope of the developing world's informal economies. In general terms, roughly half of the world's population now works in informal economies (08S3). Also, formal economies in developing nations tend to be either stagnant or growing at a far slower rate than informal economies. The world's population is expected to increase by roughly 50% by 2050, at which time population growth is expected to slow to near zero. Simple arithmetic then suggests that two-thirds of the world's population will be working in informal economies by 2050. Those working in informal economies tend to suffer from a significant amount of deliberate oppression and abuse at the hands of those in the world's formal economies via the dominant influence that those in formal economies exert on government policies (08S3). It is easy to foresee major increases in social, political, and economic instabilities resulting from the evolving world order.

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[5] ~ Limitations of Pesticides ~
Pesticide use (in terms of tonnage and toxicity per tonne) increased dramatically during the last half of the 20th century. For example, in the 1970s and 1980s, the use of hydrocarbon-based pesticides in the U.S. increased 33-fold, yet the US rate of crop loss to pests increased (91P3) (See Section [A5] of Ref. (08S1)). One should not interpret this as implying that pesticides are ineffective. The issue is clouded by other changes in agriculture during the same period that tend to favor increases in crop losses to pests. Among them are: (1) diminishing genetic diversity of food crops, (2) replacement of sound agricultural practices like strip cropping, crop rotation etc. by the planting of vast monocultures reflecting increasing population pressures on cropland, (3) increases in global trade that greatly increased the diversity of exotic pests with no natural enemies in destination countries, and (4) the "non-specificity" of pesticides, meaning that they often kill non-target organisms (including the natural enemies of targeted pests and honeybees) often resulting in resurgences of existing pests and outbreaks of new ones (03B4). These four processes probably mask any benefit of increases in pesticide-consumption that might otherwise have resulted. The outcome of the battle between genetic modifications of food crops (to produce pest-resistant species) and the genetic modification of pests via natural selection is far from clear.

The limitations of the strategy of steadily increasing the tonnages (and potency per tonne) of pesticides are now becoming apparent. Pesticides, at current dose rates, are becoming toxic to humans as well. However, humans have a disadvantage relative to smaller pests. Pests can be genetically enhanced via natural selection in something on the order of a decade (about the same time as that required to develop an improved pesticide, or a new pest-resistant plant specie). Humans, on the other hand, require far longer times to be genetically enhanced via natural selection. Humans come into contact with pesticides via the foods they eat and via agricultural workers and gardeners coming into direct physical contact with pesticides residing on plant surfaces. A British study of 143,000 people since 1982 found that gardeners and farm workers regularly exposed to pesticides have a 70% higher incidence of Parkinson's disease (a brain disease afflicting 150,000 Britons, with 10,000 new cases every year). Many pesticides are designed to be toxic to pests' nervous systems, so a link between pesticides and Parkinson's disease in humans should not be surprising (06U1). Ultimately, public-health-based constraints on pesticide dose rates seem certain to increase, yet the genetic modification of pests via natural selection is certain to continue at much the same rate. It would seem, then, that the battle between pests and people is gradually being stacked increasingly in favor of pests.

[6] ~ Could some as-yet-Unknown Development(s) Contribute Significantly to Global Food Production? ~
Plants need water, nutrients, good genes and light for survival - little else. The water issue is within the irrigation issue. The nutrients issue is mainly within the fertilizer issue. The genes issue is within the "green revolution" issue. All these issues have been analyzed above or elsewhere in this document and have all been found to offer little potential for contributing significantly to global food production on a scale needed to accommodate the seven bulleted issues listed in the Abstract. Granted, there could, in theory, be some element other than nitrogen, potassium or phosphorous that could increase food productivities significantly. However if that were true then von Liebig's Law of the Minimum would say that the productivity improvements resulting from nitrogen, potassium and phosphorous would have been minimal since that as-yet-unknown element would become the critical factor in determining cropland productivity. There have been genetically improved species of grain developed for specific regions of the world, e.g. "Nericas" rice for western Africa. However the increases in production will be consumed by a combination of western Africa's population growth and genetic improvements in pests via natural selection within a decade (See below).

There is one exception to the analysis in the paragraph above, an exception that has attracted a good bit of attention and research in recent decades. That exception is the nutrient-delivery problem in tropical soils - the cause of the low fertility of tropical soils generally. In the past few decades a way of reducing the magnitude of this problem has been developed for poor, sandy soils of the Cerrado, a semi-arid tropical region of central Brazil. Also, thousands of years ago, primitive Indian tribes in Amazonia discovered how to fix the tropical soil fertility problem. It is exciting because the process might work in a large fraction of the soils of the developing world. As a result, people today are finding small, fertile patches of soil surrounded by typically low-fertility tropical soils. Soil scientists of Brazil and the US are trying to develop a way of reproducing what these ancient tribes did, but on a massive scale. These two issues are described below.

Only light remains as a potential, not-yet-addressed source of food productivity improvements. But this is not a variable that can be manipulated. Replacing the sun by electric light bulbs, as in hydroponics, is capable of producing only the most expensive foods (some fruits and vegetables, but not grains - 80% of human food supplies) and then only under excellent growing conditions.

Any argument that contends that a yet-to-be-developed technology could sustainably increase global food supplies should begin by defining the unmet plant need that the new process is likely to serve. Since no non-addressed plant needs remain (other than the nutrient delivery problem in tropical soils), it seems unlikely that other, as-yet-unknown, processes await development.

[6A] ~ Tropical Soils - the Problems and the Potential ~
Nutrients from chemical fertilizer or manures tend to be stored in soil organic matter. When soil organic matter contents are low (as they are in tropical soils), nutrients (like nitrogen, potassium and phosphorous) tend to be leached away fairly quickly, thus the bad economics of chemical fertilizers in tropical soils generally (08F1).) The reason for low organic matter contents of tropical soils is the following. Soil organic matter is stabilized by bonding chemically with minerals (e.g. in molecular-scale tunnels found in clays, or on the surfaces of mineral particles). In that stabilized form, "Organo-mineral complexes" can last for a century or so, up to over 10 or so centuries instead of just a few years. Soil organic matter that is not stabilized by binding chemically with minerals tends to get "mineralized" (e.g. converted to CO2) and vanish from the soil. At higher temperatures, the mineralization reaction occurs faster, relative to the rate at which organic matter is stabilized by chemically bonding with minerals. This explains why temperate soils tend to contain roughly three times more organic matter than tropical soils. This, in turn, explains why the more advanced civilizations tend to be located in temperate climates. Organic matter in northern wetland soils may not form organo-mineral complexes but last for centuries anyway as a result of the lack of oxygen for most mineralization reactions. (Tree trunks at the bottoms of some lakes can also last for tens of centuries for much the same reason.)

One might be tempted to conclude that the lower soil fertilities and the lower soil-organic-matter contents of tropical soils are fundamental realities, beyond any hope of correcting. This however has not stopped scientists from poking around the edges of the problem. They could be motivated by the knowledge that any broadly applicable break-through could result in major changes in the future of mankind. Over the past few decades, a few more motives have attracted attention. First, a new breed of rice has been developed for semi-arid West Africa (See (6A1) below). Second, major improvements have been made in the productivity of the normally extremely poor sandy soils of the semi-arid Cerrado region of central Brazil (See (6A2) below). Third, many small, isolated regions of Brazil and western Africa have been discovered with very fertile soils that show that primitive people had stumbled into a way of making tropical soils fertile many thousands (500 to 7000) of years ago. These tropical soils have remained fertile to this day (See (6A3) below.).

(6A1) ~ "Nericas" Rice for West Africa:
In the late 1990s a new rice hybrid was bred to grow in the semi-arid uplands of western Africa. It produces 50% more grain per unit area of cropland, matures 30-50 days earlier, has superior weed competitiveness, greater tolerance to soil acidity and iron toxicity, and has enhanced disease-, pest-, and drought-resistance (Ref. 36 of (03R1)). (The website of the Africa Rice Center where Nericas rice was developed does not verify the 50% productivity-enhancement figure.) Nericas rice apparently does not increase the Harvest Index. Nor does it make the rice better able to make use of chemical fertilizers like the usual "Green Revolution" rice species do. Its claim to higher productivity is apparently a result of all the other improvements mentioned above. The increased pest resistance portion of this 50% productivity enhancement is only good for about a decade until genetically modified pests come along. Sub-Saharan Africa currently imports 40% of its rice needs, and rice demand doubles every 9 years or so. Taking the 50% productivity enhancement at face value, the "New Rice for Africa" can handle only about 5 years of demand-growth before western Africa is back to where it started. Clearly the development of "New Rice for Africa" is an impressive advancement. However it is also apparent that it will not have anywhere near the results that were achieved by the "Green Revolution" rice species of the 1940s and 1950s. It does not break through the theoretical "Harvest Index" barrier. The world's rice reserves are now (June 2007) at their lowest level since 1983-84. Also, rice prices are expected to double in the next few years, setting the stage for widespread food riots in West Africa (according to a warning from the World Bank (Ref. 36 of (03R1)). Nericas might postpone these food riots for a few years, but this is all that Nericas has to offer.

The same problem that has plagued all of sub-Saharan Africa for decades - the lack of financial capital (07D1) - has severely limited the benefits western Africans are able to derive from Nericas rice relative to its potential. High population growth rates create huge demands on financial capital to create the additional infrastructure that population growth demands. As a result:

The slowness at which Nericas rice spreads across western Africa creates the added problem of Nericas rice cross-breeding with the more common types of rice each year, thereby continually reducing rice yields. To make matters worse, developed world aid for developing world agriculture has dropped over the past two decades (07D1). Time is not on the side of Nericas rice in yet another way. As the genetic diversities of plants used to produce food for humans continue to diminish, the possibilities for developments of new breeds like Nericas rice continue to shrink as well.

(6A2) ~ Improved soils and genetically improved crops for the Cerrado:
Some developments over the past few decades in central Brazil have offered a glimmer of hope that a way to increase the fertility of tropical soils might be found (07O1). Brazil's Cerrado is a tropical savannah (semi-arid grassland) that covers 23% of Brazil in central Brazil. The Cerrado, historically, had some of the world's least productive soil. However the following strategy has produced major improvements in Cerrado cropland outputs.

The net result of all this has been the single largest increase in arable-land usage in the last 50 years. Crop yields were greatly increased. E.g. rice yields were 740 kg./ ha in 1974 vs. 2500 kg./ ha in 2007. Corn yields have tripled in the Cerrado's best soils. Soybeans added nitrogen and organic matter (via crop residues) to the soil. Soybean crop residues apparently hold the nitrogen and perhaps other key nutrients in place, reducing the rate at which they are leached or mineralized out of the soil (a major problem in tropical soils as noted above). Now the Cerrado yields soybeans, corn, sorghum, cotton, rice, beans and fresh produce. Brazil has historically been a major exporter of only coffee and sugar. Today Brazil is a world leader in sales of soy, beef, and orange juice (Of these, only soy is attributable to the Cerrado.) Brazil's grain output doubled in one decade. Brazil's agriculture industry now accounts for 90% of Brazil's trade surplus of more than $40 billion/ year. The bulk of this agricultural trade is apparently with nations like China and India where per-capita caloric intakes and popular demands for increased dietary diversity are increasing.

There are drawbacks however. Native fruits that depended on acid soils have vanished from large areas. The Cerrado's sandy clay soil still has a low capability for holding organic wastes (typical behavior of tropical soils). (Sand grains have much less surface area than clays, making the stabilization of soil organic matter much slower.) As a result, chemical fertilizers, animal wastes and chemical wastes added to the soil mainly pollute water sources instead of enhancing soil fertilities (07O1). This perhaps explains why such large amounts of chemical fertilizer must be applied annually to Cerrado soils. Many tropical soils also have a variety of other serious problems with soil chemistry (e.g. aluminum toxicity and excessive amounts of iron that makes phosphorous (potassium?) unavailable to plants). These problems are apparently not encountered in the Cerrado, so it is not clear how widely applicable the Cerrado strategy is. The Cerrado development is not applicable to sub-Saharan Africa and other portions of the developing world where population growth rates are high. This is because (1) inadequate transportation infrastructure (due to scarcity of financial capital) makes chemical fertilizers too expensive, and (2) African farmers cannot afford the financial capital investments and human capital investments required for low-till or no-till methods (same reason). Brazil has had an active family-planning program; so population growth rates are down significantly and a middle class is emerging. (Mexico is undergoing the same transition.) As a result, financial capital and human capital are more available for investments in transportation infrastructure, no-till- or low-till agriculture, and the high costs of high dose rates of chemical fertilizers. The Cerrado has an advantage over much of the developing world's tropical soils. It is semi-arid, so the rate of leaching of soil nutrients may be less that in more humid climates. The high inputs of energy (due to the high dose rates of chemical fertilizers) could make the Cerrado's food outputs non-economic if energy prices continue to rise faster than food prices.

(6A3) ~ Terra Preta:
An exciting development that has been receiving international attention since 2001 has vastly more potential for increasing food supplies in tropical climates than the Cerrado strategy. It is described in detail in a separate document on this website ("Terra Preta - an Inexpensive, if not Profitable, Solution to the Problems of Global Warming and Developing World Hunger") so it is only summarized here. A discovery in the mid-19th century has suggested that raising productivities of tropical soils by making fundamental changes in the chemistry of stabilization of soil organic matter might be possible (06G1). Patches, roughly 50 acres (20 ha) in size, of fertile soil ("terra preta") can be found throughout Amazonia. Ancient indian tribes created these patches 500 to 7000 years ago. The total area of these patches is believed to be about 10% of the Amazon basin -an area the size of France. These fertile patches are surrounded by typically low-fertility tropical soils. These fertile patches contain large amounts of charred wood ("char-wood"). Food scraps, bones of small animals, animal manure, crop residues and human excrement had provided organic matter for these fertile soils. This organic matter and their nutrients are apparently rapidly stabilized by chemically bonding onto the surfaces of char-wood. Char-wood is very porous and hence has offers huge surface area per kg of mass for the soil organic matter stabilization reaction to occur. The result of this stabilizing process is that the soil organic matter and its nutrients are preserved for thousands of years instead of being mineralized and released to the atmosphere as CO2 or leached into the ground water within a year or two (the fatal flaw of most tropical soils). Soil scientists from around the world are seeking ways of creating 21st century copies of terra preta cheaply and covering large areas of land (06G1) -rediscovering what ancient indian tribes learned thousands of years ago. Terra Preta even offers an additional major benefit - the ability to eliminate global warming at low cost, if not profitably. Both benefits are examined in detail in the separate document noted above.

[7] ~ The New Context of the Food Crisis - A World with Fewer Options and Increasing Demands ~
The current global "food crisis" seemed, to many, to pop up from nowhere. But there have been plenty of warnings. Below is the U.S. Department of Agriculture's projection on 5/11/07. The downward trend in global grain reserves has been apparent, and well publicized, for at least a decade now. The fact that there is no evidence that temporary, abnormal circumstances have played any role in this long-term downward trend has also been clear. If the world were to experience a year of bad weather similar to that experienced in 1972, the current "food crisis" would pale in comparison to the crisis that would arise as a result. This should be taken as a warning that advance planning ought to be done if total chaos is to be avoided. There are other serious risks facing the future of global food reserves that have not yet registered much in the USDA's grain-reserves data, or in the arenas of public discourse. Below are some of them.

On 5/11/07, the US Department of Agriculture (USDA) released its first projections of world grain supply and demand for the coming crop year 2007/2008. The USDA predicts supplies will plunge to a 53-day equivalent, their lowest level in the 47-year period for which data exists. Further, it is likely that, outside of wartime, global grain supplies have not been this low in a century, perhaps longer. Most important, 2007/08 will mark the seventh year out of the past 8 in which global grain production has fallen short of demand. This consistent shortfall has cut grain supplies from a 115-day supply in 1999/2000 to the current level of 53 days. The world is consistently failing to produce as much grain as it uses. The current low supply levels are not the result of a transient weather event, or isolated production problems. Low supplies are the result of a persistent drawdown trend (07Q1). Note that, as a result of a year (1972) of bad weather worldwide, grain prices in 1972-1974 roughly tripled. Global grain reserves at the start of 1972 were significantly higher than they are today. This is apparently the basis of the statement, often heard these days, that the world is just one poor harvest away from total chaos in world grain markets (80% of the world's foods) (08B4).

Not only are world grain stockpiles dwindling, world stockpiles of dairy products (cheese, butter, skim-milk powder, whole milk powder) dropped from around 3 million tonnes in the mid-1990s to around 0.9 million tonnes in 2008 (08B2). Global dairy product prices have risen from around $2000 / tonne in 2005-2006 to roughly $4500/ tonne in late 2007-2008 (08B2). Demand for dairy products is growing 2.5 to 3%/ year (10%/ year in China) but global outputs are rising by only 1.5 to 2%/ year (08B2).

The basic message of the document you are reading is that, contrary to the bulk of public opinion as shaped by numerous "cornucopian" writers of the day, essentially all the usual, direct options for addressing food supply problems that have been available in decades past have been foreclosed, or are nearing the point of foreclosure. Thus, as a result of (1) economic progress in portions of developing nations such as China, India and Brazil (2) trends in converting corn, soybeans, palm oil, rapeseed and sugar into "biofuels," the current "food crisis" should be easy to understand. For those who have examined so-called "footprint" analyses (02W1), Net Primary Production analyses (08S4), this author's analyses of sustainability issues related to all the major elements of the world's food supply system (08S1), downward trends in oil outputs of nearly all the world's oil-producing nations (08B1), and trends in energy intensiveness in the world's food-production systems (94P5), the current "food crisis" becomes even easier to understand - to the point of being impossible to ignore or take lightly.

No one should stop at merely "understanding" all the numerous and complex elements of the current food crisis. From there one should apply their understanding to devising potential solutions to that crisis. The possibility then exists for these potential solutions to lead to public policies that might eventually convert potential solutions into actual solutions. Below are some partial, potential solutions to the food crisis that have become apparent to this author in his analyses of the degradation of the world's soils (07S1), croplands (07S1), grazing lands (07S3), irrigated lands (07S4) and fisheries (07S5) and the sustainability of outputs of these systems (08S1) spanning some decades. No one should assume that these partial, potential, short-term solutions, if carried out, would permanently end the food crisis. They should, however, provide a means of significantly reducing some of the current most painful elements of that crisis and create a sound basis (and some time) for implementing public policies involving long-term solutions.

[7A] ~ The World's Irrigation Systems - Key Problems and Their Solutions ~
The world's irrigated croplands provide about 60% of the value of the foods the world consumes. Unless the major problems of these systems can be solved, nothing is possible except temporary solutions to the food crisis that merely postpone the inevitable. Water supply problems pose the most serious threats to the world's irrigation systems. Irrigation systems consume about 70% of mankind's consumption of fresh water. Irrigation is therefore a major cause of the problems that endanger it. These problems could greatly reduced, by such irrigation techniques as drip- or micro-irrigation. Relative to furrow- or sprinkler irrigation, such techniques cut water consumption/ use** by 30-60% (96P1). These technologies are also claimed to eliminate the problem of salt-accumulation in the root zones of irrigated plants (93P2). (**Note: water-use and water consumption are not much different for irrigation since water draining irrigated lands tends to contain significant concentrations of salt, reducing possibilities for reuse. Also, a large fraction of water supplied to irrigated croplands evaporates back into the atmosphere [leaving the salt behind]. This is the most severe in drier regions where irrigation is most common.)

Only about 1% of the world's irrigated lands use drip- or micro techniques. The main reason for this small percentage is the huge subsidies, worldwide, that taxpayers bestow on irrigators in terms of charging irrigators only 10-20% of the government's cost of supplying water to irrigators. Such public policies not only make drip- and micro-irrigation economically non-competitive, they also result in (1) irrigating crops like grass (e.g. alfalfa fields in California), practices that would not be even remotely cost-effective without heavy subsidies, and (2) shrinkage of aquifers and surface-water flows that threaten both urban water supplies and future irrigation systems. When developing nations subsidize their irrigators, they do so at the expense of their ability to repay external sources of the loans used to finance irrigation systems. This, in turn, provides sources of capital like the World Bank, the IMF and the World Trade Organization with the leverage that enables these entities to impose harsh "Structural Adjustment Programs" in a large fraction of the developing world (08S3). These have caused extreme hardship, and helped to create huge, growing, and ultimately destabilizing "informal economies." They have also been one of the main causes of arguably the largest mass migration in human history -the rural-to-urban migration in much of the developing world (08S3).

The next-most-serious danger confronting the world's irrigation systems is the salinization and water-logging of these systems. The world is littered with the remains of abandoned irrigation systems that have degraded into what are now essentially salt flats. There is uncertainty as to whether the rates of productivity decline and abandonment today are more than or less than the rate of creation of new irrigation systems. Because of the high rates of irrigation-system creation during around 1960 to 1990 and the far slower rate of irrigation system (and dam-backwater) creation since then, it is clear that the rates of productivity degradation and abandonment will increase significantly in decades to come. Lifetimes of irrigation systems apparently fall into the range of somewhat more than a century down to a perhaps half a century depending on local soil environments and precautions taken. Most of the developing world is (1) burdened with staggering external debts and/or (2) suffering from extreme scarcity of financial capital. As a result, the rates of irrigation system development where the need for such systems is greatest could hardly do anything but decline in coming decades. Even in the US, the era of large dam building has been declared dead by the US Bureau of Reclamation. One result of this is shrinking aquifers all over the US, but especially in the semi-arid and arid regions of the western US.

The problems of salinization and water-logging can be avoided by installing drainage tiles a few feet below ground. Only irrigation systems in monsoon climates can safely avoid drainage tiles. Data on the percent of irrigation systems with drainage tiles is apparently non-existent. One expert estimates, however, that only a small fraction of today's irrigation systems have such features. Even the World Bank does not require drainage tiles under the irrigation projects it finances. Drainage-tile systems also require settling ponds where salty drainage water can evaporate. Residual salts must be appropriately disposed of. This increases both the initial capital investment and annual operating costs that must be added to the already high costs of irrigation system construction and management. As aquifers and surface waters become depleted, and as increasing amounts of water get reallocated to urban- and industrial consumption, pressures grow to extract more and more productivity from each drop of irrigation water consumed. In the long run this only increases the rates of salinization, water-logging, productivity-decline, and abandonment (short-term gain, long-term pain).

Shrinkage of glaciers in just the Himalayas, the Andes, the Rocky Mountains, and the Alps threatens the continuity of water flows to a large fraction of the world's irrigation systems (and about half the world's population (06H1)). The resulting increase in pressures on irrigation systems is likely to translate into increasing rates of salinization and water-logging via the mechanism noted in the previous paragraph.

In arid and semi-arid regions of the western US (where most US irrigation systems are found), research has found that (1) the preceding half-century or so was characterized by abnormally moist climates, and (2) that this condition is now in the process of changing back to more normal, drier climatic conditions (hence all those forest fires). This, plus rapid declines in the aquifers in arid and semi-arid portions of the US, portends serious problems of all types for irrigation in the western US -- and the US citizens who consume U.S.-produced food - and the people in a large portion of the world who consume food imported from the US.

In addition, declining organic matter contents in the semi-arid grain-lands of US and Canada, threaten not only North American food supplies but also those of a large fraction of the developing world. This is because so much of that world depends of grain imports, and the US and Canada are the world's two largest exporters of grain. Making matters worse, Russia (normally the world's fifth-largest exporter of grain) is taking steps to impose increased government control over its grain exports, with the apparent intent of reducing Russia's future grain exports (08B5).

[7A1] ~ A short-term Solution to the Problems of the World's Irrigation Systems ~
The solution recommended here to the problems of salinization and water-logging is the same as the solution recommended for water-supply problems - increased usage of drip- and micro-irrigation, motivated by elimination of the huge taxpayer-financed subsidies of irrigation water supplied to irrigators worldwide. Drip- and micro-irrigation offer two crucial benefits - reduced water consumption and reduction or elimination of problems with salinization and water-logging. The politics of such a solution are likely to be far more difficult in developing nations. This is because people living in these nations already spend 50-75% of their incomes on food. So when the costs of producing 60% of value of food is significantly increased by the elimination of water subsidies and by the added investment- and maintenance costs inherent in drip- and micro-irrigation, the result is almost certain to be riots and increased levels of hunger. On the other hand, the consequences of maintaining the status quo are also far more severe in the developing world. Consequences include shrinking aquifers and surface water and falling productivities as a consequence of salinization and water-logging. Whether this recommended solution is sufficient to eliminate both key problems is a matter of speculation. In this author's estimate it is probably not sufficient. However the solution could, in theory, be implemented over a short time period. This could make other solutions with longer time horizons more viable when coupled with the short-term solution recommended here.

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[8] ~ The Role of Government Subsidies in the Food Crisis ~
The problems illustrated above are fundamental ones that run throughout the entire global food production system. Countless sustainability problems plague food production systems almost everywhere in the developing world (and in much of the developed world) (08S1). If one wants to reduce, or eliminate, any of these sustainability problems the costs tend to be huge, and far beyond the abilities of developing nations, with their extreme shortages of financial capital, to pay. But, as in irrigation systems, so many sustainability problems result, at least in part, from government subsidies. Another prime example is the world's marine fisheries where government subsidies exceed the total value of the marine harvest, and where much of the over-fishing that goes on worldwide is financed by subsidies (See Sect. (D) of Chapter 9 of Ref. (07S5)). If subsidies bestowed on the world's marine fishing fleet were eliminated, the cost of fish would increase significantly, causing considerable pain in developing nations. The analogous situation occurs in the public grazing lands of the semi-arid western US where government subsidies ($400-800 per cow) exceed typical sales prices of cattle. These subsidy estimates do not include the degradation of public semi-arid grasslands due to over-grazing. (Be careful not to attribute this degradation to public ownership of rangelands; overgrazing is even more severe on privately owned western grazing lands.) (07S3)

A major component of the current global food crisis that is also a result of government subsidies can be seen in a detailed analysis (07F2) of the process of converting food crops to "biofuels" for consumption by automobiles. That analysis showed that the conversion of corn to "biofuels" requires more energy inputs that the additional energy made available for automotive consumption. That analysis found numerous energy inputs that were neglected in the analysis used to justify the biofuels program. That analysis is also apparently valid for food inputs other than corn, i.e. soybeans, rapeseed and palm oil. Sugar-based bio-fuels produced in Brazil can apparently be done without subsidies and therefore is probably a net producer of sugar. The US biofuels program was apparently designed as a process for enriching midwestern farmers, since it apparently makes the energy crisis worse rather than better. The fact that the importation of biofuels was heavily taxed (or outlawed outright) makes the priorities of the federal legislators who designed the US bio-fuels program clear. Eliminating the numerous subsidies bestowed on the biofuels program would reduce the prices and increase the supplies of both food and energy. RECENT ADDITION: A secret detailed World Bank report (08C1) found that 75% of the increases in food prices over the past few years are attributable to "bio-fuels" production. (An additional 15% is attributed to higher prices of energy prices and fertilizer prices.) The World Bank estimate conflicts markedly with the Bush administration estimate that less than 3% of the increase in global food prices over the past few years is due to bio-fuels.

One should avoid being too ideological in terms of views of government subsidies in the world's food production systems. After all, government subsidies and NGOs financed the research that produced the Green Revolution, and financed much (or all) of the development of chemical fertilizers. Without Haber's development of chemical fertilizers, half of us would not be alive today. Subsidy elimination can also be counter-productive. Sustainability of food production systems is an attribute that costs money (short-term pain - long-term gain.) Farmers of the older portions of the developed world (Europe and parts of the Far East) are significantly more inclined to invest in food output sustainability than the rest of the world (08S1). As a result, food from these regions costs more to produce. So to compete in world trade, governments in these regions tend to subsidize food production. Globalization-related trade-negotiations don't see things that way. The rest of the world tends to demand elimination of these farm subsidies and, by inference, the elimination of the sustainability of the food outputs of these regions. This is one of many reasons why globalization is often spoken of as a "race to the bottom."

As the population of the developing world increases by about 60% during 2000-2050, the problems of freshwater shortages, salinization, waterlogging, over-fishing, over-grazing and countless others can hardly do anything but get worse. Higher food prices will create increasingly strong public demands for agricultural subsidies. This will cause even greater problems for government budget-makers, and the political repercussions associated with eliminating agricultural subsidies will dwarf those of today. It would seem that addressing food crisis problems using purely short-term approaches that (1) may not be adequate, and that (2) will almost certainly become more politically difficult and risky -- is unwise. Some combination of short-term- and long-term approaches, applied simultaneously, appears to be the only safe strategy for dealing with the global food crisis.

[9] ~ Solutions to the Food Crisis ~
[9A] ~ Short-term Solutions to the Food Crisis ~
The analysis above made a case for a short-term solution to the food crisis of mainly eliminating government subsidies. This would be a painful (in the short-term) solution (in most instances) for the developing world where people must allocate 50-75% of their incomes to the purchase of food. On the other hand, eliminating subsidies for biofuel production (at least in the US) would significantly increase food supplies for the developing world, in addition to reducing the energy crisis in the developed world. Eliminating subsidies that go to irrigators to finance 80-90% of the water that governments provide to irrigators would significantly increase the use of drip- and micro-irrigation techniques.

A subsidy-elimination strategy might not achieve a sufficient level of conversion to drip/ micro irrigation. So full conversion may require legislative solutions. Both subsidy-elimination- and legislative approaches would increase the cost of 60% of the world's food and cause much short-term pain, especially to those in developing nations. In order to induce irrigators to underlay their irrigation systems with drainage tiles to reduce productivity degradation via salinization/ water-logging and make the productivities of irrigated croplands more sustainable would almost certainly require legislative approaches. It is understood that drip-/ micro-irrigation does not require drainage tiles, so it may be possible to require making a choice between the two alternative technologies.

Eliminating subsidies for the fishing industry and for livestock grazing would also create short-term pain in terms of food price increases, but long-term gain in terms of increased sustainability of outputs. Eliminating de facto subsidies that concentrated animal feedlot operations receive in the form of lax standards for liquid-manure lagoons would result in greater supplies of livestock manure for spreading on US croplands. This would allow US farmers to increase dose rates of chemical fertilizers without serious, long-term damage to temperate soil chemistries. The result would be larger (and more sustainable) food outputs from US farmers.

[9B] ~ Long-term Solutions to the Food Crisis ~
Solutions with longer time horizons exist that are likely to be: (1) less expensive; (2) more politically popular; (3) more likely to increase in popularity over time, and (4) applicable to a far broader range of food-supply problems. Both solutions is described in detail elsewhere in this website (08S2) (07S6) (08S7) so they are only summarized in this document. The first solution is summarized below. The second solution is summarized in Section (6A3) above.

Addressing Financial Capital Scarcity in Developing Nations ~
Nearly all of the non-sustainability of the developing world's food supply systems stems from the extreme scarcity of financial capital that forces developing nations to stay focused on the here-and-now rather than on the future (08S1). The financial costs of achieving sustainability would be staggering so, in a sense, it matters little where the focus lies. That financial capital scarcity can be traced to the huge demands on financial capital posed by the cost of infrastructure growth that, in turn, is called for by the 1.3%/ year rate of developing world population growth. That cost can be computed to be about $1.2 trillion/ year, an amount that a world with median earnings of $2/ person/ day cannot afford (08S2). As a result, the bulk of this cost remains as unmet need. This explains why sub-Saharan Africa and its high population growth rate has extremely inadequate transportation infrastructure. One result of this is extremely high costs of imported chemical fertilizers (60 times that in the EU). This, in turn, explains the nutrient-mining of Africa's cropland soils and the resultant hunger. Be careful to note that this says nothing about whether sub-Saharan Africa is over-populated. It only says that Africa's population growth rates are too high.

The infrastructure-cost hypothesis also explains why nations with active family-planning programs over some decades were able to eliminate their financial scarcity problems. This enabled them to invest in human capital and technological capital, enabling them to evolve from developing-nation status to, or nearly to, developed-nation status. Examples include South Korea, Japan, Taiwan, Singapore, Hong Kong, Tunisia, the Barbados and the Bahamas. Brazil's and Mexico's more recent active family-planning programs have, thus far, led to the early stages of a middle class that may ultimately bridge the huge gap between the extreme wealth and the extreme poverty that characterizes so much of Latin America. China's active family-planning program, although draconian, is producing similar results, though at the risk of a backlash. India has little by way of family planning programs, so it has a significantly higher population growth rate than China. One result is that mass public education in India exists in name only, and only those few who can afford private educations can join India's middle class (08S5). Another consequence is the highest rate of childhood hunger in the world, even worse than in Africa. Attitudes toward family-planning within both the governments and the populace of developing nations are rapidly becoming more supportive. This is now true even in developing nations dominated by extreme forms of religious fundamentalism (08S6).

Most people are unaware of the fact that various technological advances in the past decade or two have reduced the cost of averting a birth by about two orders of magnitude in recent decades, from something on the order of $600/ birth averted down to a few dollars (07S6) (07S7). It is these advances and their costs that will ultimately determine the success or failure of any effort to eliminate the world's food crisis. These technologies are in various stages of expansion and penetration into the more remote and impoverished regions of the developing world where population growth rates are especially high. The excess of births over deaths in the developing world is about 78 million/ year, with much of this being "momentum" effects that will die out over time of their own accord. Thus the cost of eliminating the excess of births over deaths in the developing world is well under $1 billion/ year (a few percent of the annual development- and humanitarian aid that developing nations receive from external sources).

There appear to be plenty of families who have unintended pregnancies at a time when they are interested in averting a birth. This is apparent because, on average, the desired number of children per family in developing nations tends to be about one less than the final number. These issues are covered in more detail elsewhere (08S2) (07S6). All this holds out increasing possibilities for developing nations being able to: (1) make their food production systems more productive; (2) make the outputs of these systems more sustainable, and (3) achieve all this in an environment of declining population growth rates and, quite possibly, even declining populations. There are also side effects to all this. Lower fertility rates tend to result in greater investments in human capital (education). That, in turn, reduces both desired family sizes and financial capital scarcity. Also, the frequency of armed conflicts has been shown to decrease with decreasing population growth rates (04P1). Reducing the frequency of armed conflicts reduces the risks associated with all sorts of capital investments, and hence further increases the availability of capital. This creates possibilities for increasing productivities and sustainabilities of food-supply systems even further. In a world of fewer options for addressing the global food crisis, helping families to reduce actual family sizes to desired family sizes in environments that promote declining desired family sizes is probably the only really workable solution to the global food crisis.

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~ References ~
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07S1 Bruce Sundquist Topsoil Loss and Degradation - Causes, Effects, and Implications: A Global Perspective, Edition 7 (July 2007)
07S2 Bruce Sundquist Forest Land Degradation - A Global Perspective, Ed. 6 (July 2007)
07S3 Bruce Sundquist Grazing Lands Degradation - A Global Perspective, Ed. 6 (July 2007)
07S4 Bruce Sundquist Irrigated Lands Degradation - A Global Perspective, Ed. 5 (July 2007))
07S5 Bruce Sundquist Fishery Degradation - A Global Perspective, Edition 8 (July 2007)
07S6 Bruce Sundquist Strategies for Funding Family Planning, Maternal Health Care, and Battles Against HIV/AIDS in Developing Nations as Options Expand, Political Environments Shift and Needs Grow: A Critique, Ed. 4 (August 2007)
07S7 Bruce Sundquist Quinacrine Sterilization: The Controversy and the Potential, Ed.1 (January 2007)

08B1 Lester R. Brown, "Plan B Update: Is World Oil Production Peaking?" Earth Policy Institute (1/20/08) Data and additional resources at
08B2 Patrick Barta, "'Saudi Arabia of Milk' Hits Production Limits," Wall Street Journal (5/8/08) p. A1.
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08E1 Earth Policy Institute, "World Facing Huge New Challenge on Food Front" (4/16/08)
08F1 Fiona Harvey, "Soil under strain: A thinning layer of life evokes concern," Financial Times (7/16/08).
08S1 Bruce Sundquist Sustainability of the World's Outputs of Food, Wood and Freshwater for Human Consumption Edition 1 (March 2008)
08S2 Bruce Sundquist The Controversy over U.S. Support for International Family Planning - An Analysis, Edition 8 (April 2008) 
08S3 Bruce Sundquist The Informal Economy of the Developing World: The Context, The Prognosis, and a Broader Perspective, Edition 1 (March 2008)
08S4 Bruce Sundquist Human Co-Option of Net Primary Production - The Photosynthetic Limits to Global Carrying Capacity, Edition 2 (April 2008)
08S5 Somini Sengupta, "Education Push Yields Little for India's Poor," The New York Times (1/17/08).
08S6 Bruce Sundquist The Muslim World's Changing Views Toward Family Planning and Contraception, Edition 2 (March 2008)
08S7 Bruce Sundquist An Inexpensive, if not profitable, Solution to the Problems of Global Warming and Developed World Hunger, Edition 2 (September 2008)

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