Abrupt global warming could shift monsoon patterns, hurt agriculture

At times in the distant past, an abrupt change in climate has been associated with a shift of seasonal monsoons to the south, a new study concludes, causing more rain to fall over the oceans than in the Earth’s tropical regions, and leading to a dramatic drop in global vegetation growth.

If similar changes were to happen to the Earth’s climate today as a result of global warming

…The data confirming these effects were unusually compelling, researchers said.

“Changes of this type have been theorized in climate models, but we’ve never before had detailed and precise data showing such a widespread impact of abrupt climate change,” said Ed Brook, an OSU professor of geosciences. “We didn’t really expect to find such large, fast environmental changes recorded by the whole atmosphere. The data are pretty hard to ignore.”

“Both the ice core data and the stalagmites in the caves gave us the same signal, of very dry conditions over broad areas at the same time,” Brook said. “We believe the mechanism causing this was a shift in monsoon patterns, more rain falling over the ocean instead of the land. That resulted in much lower vegetation growth in the regions affected by these monsoons, in what is now India, Southeast Asia and parts of North Africa.”

Previous research has determined that the climate can shift quite rapidly in some cases, in periods as short as decades or less. This study provides a barometer of how those climate changes can affect the Earth’s capacity to grow vegetation.

EurekAlert