When extreme rainfall goes up, economic growth goes down, new research finds

More rainy days could mean a blow to the economy, according to a new study from the Potsdam Institute for Climate Impact Research in Germany.

The research, published Wednesday in Nature, found that concentrated bursts of daily rainfall decreases economic growth, especially in wealthier and industrialized countries

The study analyzes 40 years of data from more than 1,500 regions in 77 countries and zeroes in on the economic impact of intense, daily rainfall.

Global climate change, caused by human greenhouse gas emissions, is changing weather patterns around the world and making extreme precipitation more common.

Past climate research has focused primarily on temperature or annual precipitation, while this study of data from 1979 to 2019 looks at daily levels.

"If we want to think about the future and think about future climate change, it's actually the daily aspects of rainfall that we know the most about," Maximilian Kotz, a doctoral researcher at the Potsdam Institute and the study's first author, told NPR.

Water is a scarce economic resource, Kotz noted. Having more of this economic good is generally a plus, but it's not a benefit in the case of short, intense periods of rain, which can lead to flooding. Not only can flooding destroy infrastructure, it can also disrupt production and the supply chain, Kotz explained.

The researchers found that the addition of just a few inches of extreme rainfall throughout the year could shave half a percentage point off a country's annual growth. That could be significant, considering most developed nations grow by only 2 or 3 percentage points each year.

The researchers accounted for a range of other factors that might have affected economic growth over the study's time frame, like local political events and global economic trends. They concluded with "very high confidence" that there was a causal link between the changes in rainfall and the changes in economic growth, Kotz told NPR.

"This is just another demonstration of the ways in which the economy is very closely linked to climate," Kotz said. "And as a result, our prosperity and jobs are all vulnerable to possible future changes in climate."

NPR's Camila Domonoske contributed to this report.