Green Blog: Feeding Ourselves on a Warming Planet

As we have often noted here on the Green blog, one of the biggest uncertainties humanity faces regarding climate change is the potential effect on the world?s food supply.

If there?s a risk that global warming and related changes could hit us much sooner and much harder than scientists are expecting, agriculture could be the crucial realm where that occurs. In fact, we have already entered an era of sharply higher global food prices, with climate change as one of the likely causal factors.

A new paper from researchers associated with Tufts University puts the overall risk in perspective. It is billed as a working paper, meaning it has not gone through formal scientific review, but it strikes me as worth highlighting nevertheless. The findings pretty closely match the conclusions presented in some of my reporting from 2011.

The authors, Frank Ackerman and Elizabeth A. Stanton, point out that in the 1990s, research suggested that climate change would be fairly benign for agriculture. The first few degrees of warming would help agriculture expand in chilly regions, and the rising level of atmospheric carbon dioxide would act as plant fertilizer, boosting crop yields, the thinking went. More recent science has cast sharp doubt on some of those conclusions.

Yet the earlier, rosy scenario is still incorporated into a lot of economic models of global warming. As a result, economists sometimes come to the conclusion that relatively modest efforts to tackle climate change are adequate for now.

?Can we muddle along without expensive climate initiatives, and go on living ? and eating ? as before?? the authors of the new paper ask. ?Not for long, according to some of the new research on climate and agriculture.?

I would say the research they cite, though clearly an improvement over the work from the 1990s, is by no means definitive; a major new program designed to improve our predictions about climate and agriculture is still in its early phases. Anyway, what attempt to predict the future is ever definitive?

But anybody who wants a tight synopsis ? less than 20 pages ? of the emerging evidence that we are in trouble on the food supply could do worse than consulting this working paper. It recaps recent findings that the benefits on plant growth of rising carbon dioxide levels may not be as great as originally hoped, that temperature extremes due to climate change may have a severe effect on crop yields, and that fresh water scarcity could exacerbate the problems.

?If warming continues unabated, it will, in a matter of decades, reach levels at which adaptation is no longer possible,? the researchers conclude. ?Any long-run solution must involve rapid reduction of emissions, to limit the future extent of climate change.?

Source: http://green.blogs.nytimes.com/2013/02/26/feeding-ourselves-on-a-warming-planet/?partner=rss&emc=rss