Climate Change Threatens Crops

Farmers Warned to Get Ready
Climate change threatens crops

Even if global temperatures rise slowly, climate change could slash the yields of some of the world's most important crops almost in half, according to a new study co-authored by an N.C. State University scientist.

The study, recently published online in Proceedings of the National Academy of Sciences, looked at three frequently used scenarios for global warming. It found that the average U.S. yields for corn, soybeans and cotton could plummet 30 percent to 46 percent by the end of the century under the slowest warming scenario, and 63 percent to 82 percent under the quickest...

Scientists are starting to look more closely at temperature spikes and dips because they can have outsized impact, said David Walter Wolfe, a Cornell University expert on the effects of climate change on crops...A simple example, Wolfe said, is freezing. A study using the average of lows for several days might not even show below-freezing temperatures, and yet farmers may have suffered a catastrophe. At the other end of the temperature scale, one day of mid-90s temperatures can kill all the flowers on a crop of pepper plants...

Wolfe frequently speaks to farmers and said his message is always the same: They are the first generation of growers who can't count on historical climate information to help them plan things such as when to plant and what varieties to choose.

"They're no longer farming in a static environment," he said. "They can't rely on the calendar to tell them when to plant, they can't rely on the variety of seeds they have always used, and they can't rely on dealing with the same insect pests, because it's all a moving target now."


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Jay Price
2009-09-04
http://www.newsobserver.com/news/story/1674429.html