SOURCE: UCR News

DATE: September 12, 2018

SNIP: The earth beneath our feet isn’t usually the first thing that comes to mind when people think about the impacts of climate change. However, a study by a UC Riverside-led team of researchers predicts a climate-induced reduction in large soil pores, which may intensify the water cycle and contribute to more flash flooding and soil erosion by the end of the 21st century.

In a paper published Sept. 5 in Nature, the scientists studied the impact of climate change on macroporosity—the amount of large pores in the soil. Macropores, which are greater than 0.08 mm in diameter, allow water to be absorbed easily into the surrounding soil, where it can be used by plants, transport nutrients, and eventually make its way back into underground aquifers.

Using a large database of soils collected over 50 years from across the continental U.S. combined with atmospheric data from a network of weather stations, the researchers examined changes in macroporosity across a rainfall, temperature, and humidity gradient. They found macropores were more likely to develop in drier climates than humid climates, and that climate-related changes in macroporosity occur over shorter timescales than previously thought.

The researchers then used climate projections for the end of the 21st Century to predict that increasing humidity by 2080-2100 will reduce soil macroporosity in most regions of the U.S.

The consequences could be less infiltration of water into the ground, more surface runoff and erosion, and more flash flooding.