With Climate Change, Dry Regions Get Dryer and Wet Areas Get Wetter: Or Do They?

Climate change isn't occurring the same way in all locations. While some climate scientists believe that climate change will cause wet areas to become wet area and dry areas to become dryers, a new study may show that this isn't always the case.

Traditional analyses of climate change use metrics that can describe climate characteristics above the ocean; yet this becomes problematic over land. That's why in this latest study, the researchers took specific climatic properties of land surfaces into account, including where the amount of available water is limited when compared to the ocean.

In order to learn a bit more about how climate change will impact different regions, the scientists used data compiled solely on land, such as rainfall, actual evaporation and potential evaporation. This allowed them to create and examine trends in terms of a region's humidity and dryness.

So what did they find? It turns out while there was no obvious trends toward a wetter or drier climate across three-quarters of the land area, there were solid trends for the remaining quarter. That said, only half of this surface area follows the dry gets drier; wet gets wetter (DDWW) principle.

In fact, the scientists found that some regions which should have become wetter have actually become driers; this includes parts of the Amazon, Central America, tropical Africa and Asia. In addition, there are some dry areas that have become wetter, such as parts of Patagonia, central Australia and the Midwestern United States.

"Our results emphasize how we should not overly rely on simplifying principles to assess past developments in dryness and humidity," said Peter Greve, lead author of the new study, in a news release.

It seems that climate change is a bit more complicated than thought. While the DDWW principle still applies to the oceans, it appears that it may not also apply to landmasses.

The findings are published in the journal Nature Geoscience.