Atmospheric river storms that periodically hit the Western U.S. could cause as much as $3.2 billion a year in flood damage by the end of the century, a figure three times higher than a 2019 estimate, university researchers found.

Researchers also say the figure could be trimmed to about $2 billion a year if countries significantly reduce the amount of greenhouse gases released into the atmosphere.

Atmospheric rivers are airborne plumes of moisture that flow from the tropics to the mid-latitudes, where they can greatly enhance storms that reach the Western U.S., particularly California, Oregon and Washington.

The findings from the University of California at San Diego were made in a paper published in the journal Scientific Reports on Aug. 12. It was based on an updated look at differing climate models, one which put annual flood damage at $2.3 billion in the 2090s and another which put the figure at $3.2 billion heading into 2100.

“As atmospheric rivers become more intense, flood damages are on track to triple by the end of the century, but it’s not too late to limit the risk,” according to a statement by Tom Corringham, a climate economist at UCSD’s Scripps Institution of Oceanography.

The new UCSD study comes in the wake of a report from UCLA that says that climate change has roughly doubled the chances that California will experience a “megaflood” larger than the 30-day deluge that walloped the Sacramento area in 1862. The report claims that some spots could receive the equivalent of 100 inches of rain in a month.

Systems of this size have long been called 100-year storms. But many scientists believe that climate change will make megastorms occur on a more frequent basis.