A just-released report of the United Nations Environment Program (UNEP) warns that food prices are likely to rise significantly in the coming decades, reversing a century of declining food prices and expanding availability. The debate over the future of world food supply has been raging at least since the time of Thomas Malthus. In 1798, Malthus began to warn that since economic growth could not keep up with population growth, the standard of living would be driven back to subsistence level. Based on the experience of the intervening two centuries, it seems that Malthus was spectacularly wrong. Population growth in the developed world declined greatly while productivity grew faster than Malthus imagined - partially due to the population growth that did take place, enabling a more advanced division of labor. The result has been centuries of consistently rising standards of living and declining food costs. The debate was reignited in the late 1960s, when Paul Ehrlich published The Population Bomb, in which he predicted that "In the 1970s and 1980s... hundreds of millions of people are going to starve to death in spite of any crash programs embarked upon now." Ehrlich was involved in a famous bet with economist Julian Simon, who said the coming years would see increased supply and declining commodity prices. Simon won the bet. In 1972, the think tank Club of Rome published a report, "The Limits to Growth," with a pessimistic outlook similar to Ehrlich's. That the Malthusians have been spectacularly wrong in the past does not mean dire predictions will never be justified in the future. It is obvious that the Earth cannot sustain indefinite population growth. So the UNEP report has to be considered on its merits, not its pedigree. The report discusses some plausible reasons for concern. One is climate change, a factor that many experts expect to accelerate in the coming decades and which could result in desertification of many areas. Another is environmental degradation; up until now, accumulation of pollutants hasn't made a meaningful impact on yields, but that doesn't mean it never could. Another concern mentioned is overfishing; again, fish yields cannot rise indefinitely. But considered as a whole, the report ultimately brings us back to Malthus, Ehrlich and the Club of Rome. A summary published by UNEP explains that "many of the factors blamed for the current food crisis - drought, biofuels, high oil prices, low grain stocks and especially speculation in food stocks - may worsen substantially in the coming decades." This statement is not well-founded. Low grain stocks are, by their very nature, a transient cause of price increases; even if prices go through the roof, some of the production will be used to increase stocks. And speculation in food stocks has been with us for millennia; citing this as a reason for a worsening crisis in the future is little short of bizarre. In the "current food crisis," the dramatic rise in food prices from the beginning of 2007 through mid-2008 has already been reversed; over the last six months prices have gone down and are nearing their 2006 level. The summary also states that "over one-third of the world's cereals are being used as animal feed, rising to 50 percent by 2050. Continuing to feed cereals to growing numbers of livestock will aggravate poverty and environmental degradation." This statement reverses cause and effect; the growing number of livestock is a sign of prosperity, not a cause of poverty. Even the more plausible explanations don't seem credible to me as a source of crisis in the near decades. Climate change does have the potential to take vast areas out of cultivation, but simultaneously is likely to make vast areas of the far North cultivable. Such a process would not be a wash for human welfare, but it is likely to be a wash for food production. Pollution has not been getting any worse in recent decades, so it does not seem a promising trigger for a looming crisis. As long as mankind is limited to our current home on planet Earth, there will be unavoidable limits to growth and they are worthy of careful consideration. But the current UNEP report seems to me a rehash of poorly thought-out warnings of the past. email@example.com Asher Meir is research director at the Business Ethics Center of Jerusalem (www.besr.org), an independent institute in the Jerusalem Institute of Technology.