Saturday, January 23, 2010

Sahara Desert Greening Due to Climate Change?

From National Geographic no less

Desertification, drought, and despair—that's what global warming has in store for much of Africa. Or so we hear.

Emerging evidence is painting a very different scenario, one in which rising temperatures could benefit millions of Africans in the driest parts of the continent.

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

An explosion in plant growth has been predicted by some climate models.

For instance, in 2005 a team led by Reindert Haarsma of the Royal Netherlands Meteorological Institute in De Bilt, the Netherlands, forecast significantly more future rainfall in the Sahel.

The study in Geophysical Research Letters predicted that rainfall in the July to September wet season would rise by up to two millimeters a day by 2080.

Satellite data shows "that indeed during the last decade, the Sahel is becoming more green," Haarsma said.

Even so, climate scientists don't agree on how future climate change will affect the Sahel: Some studies simulate a decrease in rainfall.

"This issue is still rather uncertain," Haarsma said.

Max Planck's Claussen said North Africa is the area of greatest disagreement among climate change modelers.

Forecasting how global warming will affect the region is complicated by its vast size and the unpredictable influence of high-altitude winds that disperse monsoon rains, Claussen added.

"Half the models follow a wetter trend, and half a drier trend."

One reason I am skeptical of Climate Science. 

No comments: