In what is being called an aggressive estimate of how climate change will affect agriculture, a new report by the Universal Ecological Fund argues that rising temperatures will diminish yields of the staple crops rice, wheat and corn in much of the developing world.

Lower yields, the report contends, will exacerbate food price volatility — with skyrocketing food prices already causing instability in places like Tunisia — and result in more undernourished people.

Overall, the U.S. branch of the Argentine group Fundación Ecológica Universal estimates that within the next decade there will be a 14 percent gap between a shrinking supply and a rising demand of wheat, an 11 percent supply-demand gap in rice, and a 9 percent shortfall in corn. In one bright spot, the report predicts a 5 percent surplus in soybeans.

A senior analyst at the U.N. Food and Agriculture Organization criticized the report’s methodology. Josef Schmidhuber argued that falling incomes are a much stronger driver of food insecurity than agricultural production.