Climate change threatens African farmland: study

Jasmin Melvin, Reuters 2 Jun 09;

WASHINGTON (Reuters) - Climate change could cost the African continent more farmland than the United States uses to plant its eight major field crops combined, according to a study published in the June issue of Environmental Science and Policy.

Farming on up to 1 million square kilometers (247 million acres) of land in Africa could subside by 2050 as climate change makes areas too hot and dry for growing crops, the study said.

The latest U.S. Agriculture Department data puts plantings of the eight major U.S. field crops combined at 246 million acres for the coming year.

Though unsuitable for crops, the land could still sustain livestock, which are more tolerant to heat and drought, researchers from the Nairobi-based International Livestock Research Institute and the United Kingdom's Waen Associates found.

Boosting livestock production could provide the 20 million to 35 million people living in these areas with a means to stay on their land and make an income, researchers said.

"Livestock can provide poor households with a buffer against the risk of climate change and allow them to take advantage of the increasing demand for animal products in Africa," said Philip Thornton, a scientist at the Institute and co-author of the paper.

Carlos Sere, the Institute's director general, noted that the addition of livestock would have to be done sustainably. But changing weather conditions and increasing demand for meat will make the addition inevitable, he said.

Thornton, along with Peter Jones of Waen Associates, looked at dry regions across Africa and identified areas already struggling with crop failures in at least one of every six growing seasons.

Using climate models, they determined that if carbon emissions remain high by 2050, the number of reliable crop growing days would fall below 90 for almost 1 million square kilometers of arid and semi-arid lands in Africa.

With fewer carbon emissions, the number of growing days would still fall below 90 for some 500,000 square kilometers (124 million acres), the study found.

Maize, the most widely grown staple crop in Africa, "will basically no longer be possible" to cultivate with fewer than 90 days to grow, the study said.

Even millet, a staple grain in Africa considered to be a drought-tolerant crop, would be at risk of crop failure in areas unable to meet the 90-day mark, the researchers found.

INVESTMENT NEEDED FOR MORE ACCURACY

The study pinpointed areas in Africa where small farmers would be best served by transitioning more of their enterprise to livestock than crops.

But much remains unknown about local impacts of climate change as current climate science and models today are best suited for regional studies, the researchers said.

"There is currently a mismatch between the kind of localized climate change impact information that is urgently needed, and what can objectively be supplied," the study said.

Investment to improve the accuracy of climate models could help groups determine the communities most at risk from global warming, the researchers said.

But there is a "point at which households and farming systems become so stressed that there are few alternatives to an exit from farming," the study said.

Identifying areas at risk could help governments and aid groups limit poor farmers' need to abandon agriculture by developing policy and agendas that mitigate climate change.

Climate change talks are now going on in Bonn, Germany, with delegates from 182 countries. The meetings may lay the framework for an international climate change deal to be discussed in Copenhagen in December.

(Reporting by Jasmin Melvin; Editing by David Gregorio)