March 15, 2011

US study focuses on corn's susceptibility to climate change

A study headed by Stanford University in the US has shown that corn may be more susceptible to global warming than was originally thought.

The study showed that an increase of 1 degree Celsius (1.8 degrees Fahrenheit) in temperatures would reduce yields for 65% of Africa's corn fields, under the assumption of optimal rainfall. The same warming under drought conditions would slash corn yields throughout Africa, with reductions of 20% or more in 75% of growing areas.

"The pronounced effect of heat on corn was surprising because we assumed corn to be among the more heat-tolerant crops," said Marianne Banziger, co-author of the study and deputy head of research at the International Maize and Wheat Improvement Centre, or Cimmyt.

World food production will have to rise 70% between 2010 and 2050 as the world population grows to 9 billion people and increasing incomes result in an increase in meat and dairy consumption. Crop failures look probable to become more common this century as climate change results in more severe weather, a study led by the UK's University of Leeds has shown.

David Lobell, an assistant professor of environmental earth-system science at Stanford who headed the study, connected the results of 20,000 field trials of corn in sub-Saharan Africa with weather data from across the area. The field data was gathered by El Batan, Mexico-based Cimmyt between 1999 and 2007 as part of corn-improvement trials.

The study showed that the longer corn is exposed to temperatures above 30 degrees Celsius (86 degrees Fahrenheit), the more yields decrease.