Rising global temperatures will likely lead to wildly volatile corn prices, a factor that will create more uncertainty than biofuel policies or energy markets, a new study finds.

The paper, published yesterday in Nature Climate Change, finds that hotter, drier conditions in the near term are more likely to destabilize the price of corn than energy policy or market forces. Throw in biofuels policies like the renewable fuel standard, for example -- which projects the output of 36 billion gallons of biofuels annually by 2022 -- and it enhances the price sensitivity to climate by 50 percent.

Climate's level of influence on corn commodity markets was unexpected, said Noah Diffenbaugh, an assistant professor in the Department of Environmental Earth System Science at Stanford University and a fellow at the Woods Institute for the Environment, who served as lead author of the report.

"My expectation before we did the analysis was that climate had a minor influence over socioeconomic conditions, especially over the near-term period," he said. "I was surprised to find that climate was the biggest influence by quite a bit."

Many global organizations, including the Organisation for Economic Co-operation and Development, the U.N. Food and Agriculture Organization and the International Food Policy Research Institute, have attributed rising price volatility and food insecurity to bioenergy policies in the United States and abroad.

The year-to-year swings in prices mean greater uncertainty for individuals and investors. The price of corn influences the income of farmers, the cost to farmers, energy markets for biofuels and future blending rates for ethanol in gasoline.

U.S. EPA recently approved the use of E15, a 15 percent ethanol-gasoline blend that some economists say could boost the ethanol market growth by up to 50 percent if heartily adopted. E15 has faced recent opposition by industries who claim the higher blend will affect commodity prices and damage engines.

Unless corn farmers increase their crops' heat tolerance by as much as 6 degrees Fahrenheit, the current corn belt will have to move northward. Corn grown outside of Des Moines, Iowa, will shift to northern Minnesota in the next 10 to 30 years, said Diffenbaugh, and some zones will cross the Canadian border.

The next step, said Diffenbaugh, is seeing how society deals with climate change. Adaptation methods in agricultural technology, land use or other factors could tackle what the models can't answer.

"Human reactions are really what's going to happen on the ground," he said.

Researchers from Purdue University also contributed to the report.