NEWS

Rising temps increase risks of crop failure, livestock mortality—USDA

05/27/2008

Allison Winter, Greenwire reporter

Farmers face higher risks of crop failures, livestock mortality and weed invasions as the climate warms over the next 50 years, according to a new federal study.

The Agriculture Department released the peer-reviewed report today, the result of a two-year effort by 13 federal agencies and 38 authors from universities, government and nonprofit groups. The report—a domestic response to the sweeping assessments last year from the United Nations’ Intergovernmental Panel on Climate Change—was also vetted by the White House Office of Management and Budget.

Extreme temperatures and variability in precipitation could decrease overall production of U.S. crops. The report predicts that grain and oilseed crops will mature more rapidly but have a higher risk of crop failure.

Corn yields, which have been steadily increasing, could drop 5 percent if other changes are not made to the crop, according to the assessment.

"A lot of our crops could suffer reduction in production," said Jerry Hatfield, a scientist at USDA. "We project declines in corn production and rice production."

Corn is sensitive to higher temperatures, especially at critical stages for the crop of pollination and reproduction.

But not all crops would fare as badly. One winner in the climate change scenario could be soybeans, which are more resistant to high temperatures for reproduction and may see optimal growth conditions in the already soybean-rich region of the Midwest.

Higher temperatures will harm livestock. The quality of Western forage is expected to decrease, and cows could see higher mortality on hotter summer days. Hotter temperatures also cause reduced productivity of dairy herds.

The report is a synthesis of other scientific assessments and draws on their various predictions for warming temperatures. It focuses on the changes that would happen in the next 25 to 50 years, when various warming predictions are closer together and near-term changes to policy or emissions would have little effect.

The group was tasked with compiling information on the effects of climate change in the United States as part of a federal climate science program that will include 20 other reports. It is intended to serve as a basis for federal resource managers to plan responses to climate change.