Climate Change-Driven Drought Causes Major Crop Losses

Record heat and drought conditions, which some scientists have linked to climate change, are causing trouble for the nation’s farmers and causing the USDA to drastically lower estimates for crops at the heart of the American food supply like corn and soy.

A warm spring had many growers optimistic, leading them to plant more acres than usual. Across the Midwest, many farmers started their corn crops a couple of weeks early because of warm weather. Indeed, the first six months of this year have been the warmest since recordkeeping began. This spring was first time that average temperatures in March, April and May all ranked among the ten warmest on record. Warm spring weather, accompanied by strong rainfall, can be helpful for many crops.

But June was unusually hot as well, and it was dry, causing bumper plantings to wither on fields across much of the U.S. This June ranked among the top ten most dry on record in the continental U.S. By mid-July, about 78% of the country’s corn-belt was experiencing drought to some degree. And this summer’s 10-day extreme heat wave, which broke more than 3,800 records across the U.S. put additional stress on crops.

For farmers across the Midwest, the heat wave could not have come at a worse time.“It’s emotionally draining,” Indiana corn and soybean farmer Don Villwock told CNN. “The crop got out of the ground very well. We were so optimistic. But maybe a few of us were counting our eggs before they were hatched.”

The heatwave struck during the vital period when corn crops normally pollenate. But pollen dies off when temperatures reach over 95 degrees. As a result, unpollenated corn ears, without silk or kernels, have become an unusually common sight in many fields. The drought has hit cattle ranchers, too. Faced with water shortages, withering fields, and pastures scorched by wildfires, many ranchers have decided to sell off their cattle early this year. Last month, some livestock auction houses saw five times as many cattle offered for sale as were auctioned off in June 2011.

“A lot of these producers, large and small, were thinking of expanding their herds. Things looked good,” Agriculture Department cattle analyst Ken Mathews told The New York Times. “When the drought resurrected itself, that blew those plans apart.”

Scientists generally are reluctant to directly link any specific weather event to global warming, because so many factors are at play. But scientists from Germany’s Potsdam Institute for Climate Impact Research recently concluded that the high rate of extreme weather events like heat and heavy rainfall worldwide is not merely coincidental.

“Global warming can generally not be proven to cause individual extreme events – but in the sum of events the link to climate change becomes clear,” said Dim Coumou, lead author of the study. “It is not a question of yes or no, but a question of probabilities,” Coumou explained. The recent high incidence of weather records is no longer normal, he added.

Others have reached similar conclusions. The National Climactic Data Center calculated the odds that the heat wave is a fluke, putting the chances at about 1 in 1.6 million.

This is not the first time that scientists have suspected that global warming has impacted agriculture worldwide. Another major study, published in Science in 2011, found that climate change has previously led to falling crop yields worldwide. Corn production was down 3.8% and wheat down 5.5% in 2008, and the researchers concluded that production was lower than it would have been without climate change.