The link between greenhouse gasses and African rainfall

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New research demonstrates for the first time that an increase in greenhouse gas concentrations thousands of years ago was a key factor in causing substantially more rainfall in two major regions of Africa. The finding provides new evidence that the current increase in greenhouse gases will have an important impact on Africa’s future climate.

The study, led by the National Center for Atmospheric Research (NCAR), is being published this week in Science.

New research demonstrates for the first time that an increase in greenhouse gas concentrations thousands of years ago was a key factor in causing substantially more rainfall in two major regions of Africa. The finding provides new evidence that the current increase in greenhouse gases will have an important impact on Africa’s future climate.

The study, led by the National Center for Atmospheric Research (NCAR), is being published this week in Science.

“The future impact of greenhouse gases on rainfall in Africa is a critical socioeconomic issue,” said NCAR scientist Bette Otto-Bliesner, the lead author. “Africa’s climate seems destined to change, with far-reaching implications for water resources and agriculture.”

The research drew on advanced computer simulations and analyses of sediments and other records of past climate. It was funded by the National Science Foundation, which is NCAR’s sponsor, and the Department of Energy Office of Science.

Otto-Bliesner and her co-authors in the United States and China set out to understand the reasons behind dramatic climate shifts that took place in Africa thousands of years ago.

Lakes and other water features, such as the Ubari Oasis in southern Libya, were more prevalent across now-dry parts of Africa during past periods of more-plentiful precipitation. (Wikimedia Commons photo by Sfivat.)

As the ice sheets that had covered large parts of North America and northern Europe started retreating from their maximum extent around 21,000 years ago, Africa’s climate responded in a way that has puzzled scientists. Following a long dry spell during the glacial maximum, the amount of rainfall in Africa abruptly increased, starting around 14,700 years ago and continuing until around 5,000 years ago. 

Greenhouse effect image via Shutterstock.

Read more at NCAR.