An international panel of scientists writing in the Feb. 12 edition of the journal Science is urging world leaders to "dramatically alter their notions about sustainable agriculture to prevent a major starvation catastrophe" by the end of the century.

Specifically, they are urging world leaders to "get beyond popular biases against the use of agricultural biotechnology," particularly crops that are genetically modified to produce greater yields in harsher conditions, and to base the regulation of such crops on the best-available science.

"You're looking at a 20-30% decline in production yields in the next 50 years for major crops between the latitudes of southern California or Southern Europe to South Africa," said David Battisti, a University of Washington atmospheric sciences professor.

He is a co-author of a Perspectives article in Science that urges food production experts, scientists and world leaders to "begin thinking in dramatically different ways to meet food needs in a significantly warmer world."

"I grow increasingly concerned that we have not yet understood what it will take to feed a growing population on a warming planet," said lead author Nina Federoff, science and technology adviser to Secretary of State Hillary Clinton and a biology professor at Pennsylvania State University.

The challenge is becoming more difficult, the scientists said, because the world's population is likely to increase to 9 billion people by 2050.

Feeding all of these people will require doubling the grain production in the tropics, Battisti said, but a potentially warmer climate will reduce yields because the temperature will be too high to achieve the most efficient photosynthesis. That factor, combined with potentially less rainfall in major food-producing regions and increasing pressure from pests and pathogens, is likely to cut major food crop yields a minimum of 20-30%.

According to the article, yields from some of the most important crops begin to decline sharply when average temperatures exceed about 30 degrees C (86 degrees F).

The authors advocate developing systems that have the potential to decrease the land, energy and fresh water needed for agriculture and at the same time reduce the pollution associated with agricultural chemicals and animal waste. [Full Story]