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In case you reached this page other than via Sustainability FAQ, that page and its subsidiaries are concerned with showing that human material progress is sustainable in the very long term and also is desirable. It does this by showing that claimed show stoppers can be overcome. The emphasis is on technology.

This page discusses mainly short term prospects for food supply as such material is readily available. When we look far into the future, many more technological possibilities present themselves. I hope to deal with some of them in an improved version.

This section is substantially based on How Much Land can Ten Billion People Spare for Nature? by Paul E. Waggoner, published in 1994 by the Council for Agricultural Science and Technology (CAST). I took advantage of CAST's blanket permission to reprint their reports, so there it is. Printed copies of the Waggoner report can be obtained from CAST.

How Much Land Can Ten Billion People Spare for Nature? by Paul E. Waggoner, published by the Council for Agricultural Science and Technology, 4420 West Lincoln Way, Ames, IA 50014-3447, Internet: b1cast@exnet.iastate.edu. It costs $15.00 + $3.00 shipping. They have other reports whose titles seem interesting. The web page CAST has their press releases and some full text reports.

The gist of the report is that agricultural productivity is continuing to grow rapidly, and that ten billion people can be supported at present levels of technology, though it will require improvements to support them at an American standard of meat consumption. The report envisages considerable land being withdrawn from agricultural production so as to leave more land for nature. I suppose it is CAST's bow to political correctness.

2002 May 1: High Yield Conservation

is a web site devoted to making the point that higher yields permit more land to be reserved for nature.

The report discusses the major problems that have been proposed as possible show stoppers including water supply, erosion and pollution. It compares American and Europe with less developed countries.


Some 1995 postings on the sci.environment newsgroup claimed that world fish production was in decline in relation to population. They may have been based on a report by Population Action International making this claim.

Michael Fumento has a column arguing the opposite because of the rapid increase in the production of farmed fish.

Wild and tame fish production, millions of tons
1983 1993
wild fish 51 56
farmed fish 6.9 15.8
total 57.9 71.8

This is a 24 percent increase in total fish. In the same period world population increased by 16 percent. Fumento's article is based on a UN FAO report entitled "The State of World Fisheries and Aquaculture". Fumento says that with regard to fish, the world is making the transition from hunting and gathering to agriculture. This transition was made 10,000 years ago on land.

If the amount of tamed fish doubles every ten years as it has been doing, it will pass wild fish in less than 20 years. I suppose it can do that before it encounters some limit. Most likely, the limit encountered will first be on the demand side. The aquaculture lobby will be demanding price supports.

A less optimistic article by Brian Rothschild is How Bountiful are Ocean Fisheries? published in the on-line magazine Consequences. It seems to expect ocean fishing to top out at 100 million tons per year. It is also less optimistic about aquaculture, pointing out that present aquaculture gets some of the protein required from ocean fish like menhaden that aren't eaten by people.

My own opinion is that aquaculture will continue to grow. As for ocean fishing there are large possibilities of ocean fertilization that have not yet been experimentally explored. See iron fertilization for a discussion that is mainly oriented to iron fertilization as a way of absorbing CO2, but it can also increase fish populations.

The Food and Agricultural Organization (FAO) Web page contains excellent agricultural statistics from all countries. It is in a form suitable for on-line reading and also for downloading into spreadsheets. With that available, there is little excuse for the misinformation I see in many newsgroups, e.g. little excuse for Paul Ehrlich's "Netherlands fallacy" fallacy.

Robert Kates has an article Ending Hunger: Current Status and Future Prospects in the on-line magazine Consequences. It expresses a strongly liberal viewpoint, advocating international entitlement programs, etc. and concentrating entirely on institutional matters and with no direct discusssion of agricultural technology. Maybe it can be regarded as putting an upper bound on the problem as seen by the international community. It also has a certain vagueness, referring to "the most detailed long-term computer simulation of future food availability" without saying who did it. If it was the Meadows's, I wouldn't believe it.

On 1997 August 22 issue of Science News has an article by Janet Raloff entitled "Can Grain Yields Keep Pace: Stiff challenges face today's breeders and tomorrow's farmers". It reports various opinions on the sustainability of agricultural progress. Here are some points:

  1. U.S. harvests doubled over the last half century, while the area under cultivation held steady and the number of farmers shrank from 6.2 million to 2.2 million.

  2. Just three crops - rice, wheat and corn - provide 49 percent of the calories people consume worldwide.

  3. For all three crops, world yields rose rapidly up to 1990 but have grown rather slowly since then.

  4. There are various opinions about future prospects. As usual, Lester Brown of Worldwatch has the gloomiest view. He has had the gloomiest view since he founded Worldwatch in 1974. (Actually Paul Ehrlich was even gloomier in his 1968 The Population Bomb.)

  5. Rice yields grew at 2.1 percent annually from 1960 through the 80s have grown at half that rate recently. Wheat yield growth went from 2.6 percent down to 0.1 percent. Corn yield growth went down from 2.6 percent down to half that but then rebounded to 1.7 percent annually.

  6. Japanese rice yields peaked at 4.7 tonnes/hectare.

  7. UK wheat yields peaked at 7.5 tonnes/hectare.

  8. US corn yields haven't gone above 7.5 tonnes/hectare.

  9. Thomas Sinclair of USDA looked for record yields to estimate what is possible. He found corn at 17.3 tonnes/hectare, rice at 15.2 tonnes/hectare in isolated cases. 2003 note: The 2002 winning Iowa yield was 28 tonnes/hectare.

  10. Sinclair also found that farmers who could get greater yields with more fertilizer are easing off on fertilizer at present prices of grain and fertilizer.

  11. Brown interprets this as indicating that growers may be hitting a limit on what a cereal's genetics will allow. Raloff writes "Most breeders are more sanguine, although far from complacent."

  12. Khush, of the International Rice Research Institute (IRRI) in the Philippines, is working on a new rice to be available in 2003 that will give a 20 percent increase.

  13. CYMMYT, in Mexico, is developing hybrid wheats that they hope will have the yield advantages of hybrid corn.

  14. Water is considered to be limiting in many places, but the usual methods of irrigation are only 30 percent efficient. Therefore, there is room for large improvement.

  15. The combined annual budgets of the crop improvement institutes comes to about $230 million annually. The donor nations are showing signs of "donor fatigue."

  16. Paul Waggoner is quoted as saying if "we simply do a respectable job" of husbanding agricultural resources, "we should be able to continue feeding the world on our present acreage or something close to that." Waggoner is the author of How much land can ten billion spare for nature?

I have several comments.

  1. The world has been fed rather adequately recently, and the result has been downward pressure on agricultural prices. The lowered payoff for fertilizer noted above is a consequence of that. If more demand increases prices, increased fertilization will be profitable and so will other ways of increasing production that are regarded as too expensive at present. More irrigation is another example. Very large scale water projects may again become cost-effective.

  2. Maybe the countries that need increased yields would find it to their advantage to fund the international agricultural research institutes. Depending on "donor nations" may have been warranted when China, India and Indonesia were very poor, but now dependency is just a bad habit. [India gives the International Rice Research Institute $500,000 per year. It could afford the whole $230 million per year that the crop improvement institutes spend.]

  3. Genetic engineering has only begun to pay off.

  4. Probably continuing present methods of improvement can get us up to American standard of living for a population of up to 15 billion. Should population expand much beyond that, fundamentally new technologies may be required. 2001 note: I now think that genetically engineered agricultural plants will be required to bring 15 billion to American standards.

Lightening the Tread of Population on the Land: American Examples by PAUL E. WAGGONER of The Connecticut Agricultural Experiment Station, New Haven, CT and JESSE H. AUSUBEL and IDDO K. WERNICK of The Program for the Human Environment, The Rockefeller University discuss how the U.S. is using enough less land per inhabitant so that we might give back 90 million hectares to nature.

Here's the web site of Archer Daniel Midlands, the largest American grain trading company. Naturally they hope for increased demand for American agricultural products, especially from China. The Chinese expect to meet their own needs and don't anticipate importing as much food as ADM apparently hopes they will.

IIASA (The International Institute of Applied Systems Analysis in Laxenburg, Austria has produced a 1999 report Can China Feed Itself? by Gerhard K. Heilig. The conclusion is that China can feed itself. The main shortage is water, and major water projects are required. The report explicitly disagrees with a 1995 Worldwatch popular book entitled Who Will Feed China? IIASA is a very competent outfit and this report looks very thorough, and it is based on newly available Chinese statistics. The report is based on a 4 1/2 year collaboration with the Geographic Institute of the Chinese Academy of Sciences and other Chinese institutions and included Chinese scholars resident in Laxenburg, Austria.

An important recent symposium

Plants and Population: Is there time? is the report of a symposium sponsored by the National Academy of Sciences in 1998 December. All the papers and most of the comments given at the symposium are in a very nice html format. There were substantial differences of opinion about food prospects. I suppose this symposium should be regarded as expressing the various views of people in the international food research establishment.

The economists in the session entitled Demographic and economic projections of food demand and supply. unanimously agreed that world food production in the next 25 years would be limited by demand and not by production possibilities. This was without considering advances made possible by genetic engineering. An important negative side effect of the excellent prospects for food supply in the next 25 years has been the reduced expenditures by governments and international foundations on ways of increasing agricultural productivity. The International Rice Research Institute in the Philippines is in particulary dire financial difficulty.

D. Gale Johnson extensively quotes Peter Lindert of U.C. Davis to the effect that soils are not getting worse as many claim - including the presidents of the US and Chinese national academies of sciences. Extensive quotes are included in the page on Erosion.

The speakers in the session entitled Limits on agriculture: land, water, energy and biological resources saw more problems and some of them tended to the presently fashionable views on sustainability. They didn't directly disagree with the economists.

The session Plant and other biotechnologies gave an optimistic view of the possibilities presented by genetic engineering. Luis Herrera-Estrella described recent success in making local crop plants that tolerate high soil aluminum levels by introducing bacterial genes that enhance the plants' ability to secrete small organic acid molecules to chelate (surround it with something that limits its chemical activity) the aluminum. Since acid soils with aluminum constitute 40 percent of the soils in tropical countries this is a very important development. Richard Meagher of the University of Georgia described the use of plants to remove heavy metals and other undesirable materials from soil.

In a commentary Dennis Avery of the Hudson Institute described the efforts of environmental ideologists to turn back the clock on agriculture. He was the only one who dared challenge the environmental movement directly. I agree with Avery that irrational ideologies are the main danger to human progress in the near future.

The final session Biodiversity and multiple land use demands discussed the interaction between agriculture and preserving biodiversity.

The summary by the conference organizer described the different views, except Avery's, in a way that will be helpful to people who haven't time to read the individual papers.

From the point of view of the long term sustainability of human progress, the 25 year time frame of the conference was too limiting. In particular, no-one proposed any substantially new ideas.

Many plants can grow in seawater, but none of the crop plants can. Maybe wheat, rice, potatoes, etc. can be genetically engineered to use seawater instead of requiring fresh water. That would solve the agricultural water problem. This is a pure speculation on my part.

I, John McCarthy welcome comments; email them to jmc at cs dot stanford dot edu.

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