Farmers already adapting to erratic weather
Weather and climate aren’t the same, but near-term weather cycles and longer-term changes in climate have this in common: Both will bring more extremes of wet and dry years. So far, farmers are adapting to both.
In the short run, the odds for drought in 2013 remain high.
“There’s essentially no way the drought is going to go away,” says Don Wilhite, a University of Nebraska-Lincoln (UNL) climatologist. “It’s going to continue over some parts of the country; some areas may get better.”
Wilhite, who started the National Drought Mitigation Center at UNL, says Pacific Ocean temperatures used in longterm forecasts are neutral, with neither a La Niña (the cooler-than-normal sea surface linked to Midwest drought) nor an El Niño (the opposite of warmer waters).
Similarities between last year’s winter and this one still hint at drought, he says.
Iowa State University climatologist Elwynn Taylor shares Wilhite’s hunches.
After three years with U.S. average corn yields below the trendline, “this will probably be the fourth,” he says.
Taylor sees similarities between the widespread drought of 1988 and lingering drought in 1989. Much of Iowa escaped the second one; areas to the west did not.
“That doesn’t mean the drought won’t come back,” Taylor says. “If we have a year like 1989, which is very possible because we’ve done it four times in history, then drought is probably over to the east of Interstate 35, and it’s probably not over west of I-35.”
Taylor advises farmers west of I-35 to plant corn “at the lower end of the recommended population as opposed to the higher side.” It’s something many in the Great Plains are considering.
Taylor bases his views on historical records. “Four times we’ve had consistent yields for 18 years followed by 25 years of volatile weather,” he says. That shows up if you plot corn yields. Similar weather patterns show up in tree-ring studies going back 800 years, he says.
Layered over these weather cycles, climate is already showing long-term trends toward even more extremes.
Another ISU climatologist, Gene Takle, says farmers are already adapting to a changing climate.
“In Iowa, in the last half of the 20th century, we’ve had more years with annual precipitation of over 40 inches and less than 25 inches,” Takle says.
Until 2012, Iowa and much of the Midwest seemed to be getting wetter, not drier. That wasn’t a surprise to climate scientists. As the planet warms, the atmosphere holds more moisture. Some areas, including parts of the Midwest, were expected to be wetter in most years.
Takle is one of two convening lead authors of the agriculture chapter of the National Climate Assessment, a study mandated by a 1990 federal law. A draft of the assessment, written by 240 scientists, came out last year. It describes how increasing climate change will affect different regions of the U.S. and different sectors of the economy.