Climate Change Increases Extreme Precipitation Levels: More Flooding from Major Storms

Climate change may not just warm us up--it may also create more intense storms. Now, researchers from the NOAA have found that rainfall or snowfall dumped from storms could grow significantly heavier in most of the United States by the end of this century.

The scientists found that as the atmosphere becomes warmer, sea surface temperatures also rise. In fact, it's already happening. The Atlantic Ocean has warmed by almost 2 degrees Fahrenheit between 1895 and 2011. This warming increases the rate of evaporation and, in consequence, the amount of water available in the atmosphere. In fact, the atmosphere itself can hold more water due to warmer temperatures, and researchers estimate that the atmospheric water vapor levels will jump by 20 to 30 percent at the end of this century. This, in turn, will push up the maximum precipitation by a corresponding amount.

"We conclude that the most scientifically sound project is that [probable maximum precipitation] values will increase in the future and raise the risk of damaging floods. These conclusions apply not only to the U.S., but also globally to almost all other areas," wrote the researchers in the study.

Some storms thrive in "Goldilocks" conditions--that is, situations where the weather is neither too hot nor too cold. Snowstorms in particular can have massively increased precipitation levels if the atmosphere is only slightly warmer than usual. This latest study promotes the idea that storms could become far more serious in the future.

"We have high confidence that the most extreme rainfalls will become even more intense, as it is virtually certain that the atmosphere will provide more water to fuel these events," said lead author Kenneth Kunkel in an interview with the LA Times.

The possibility of heavier rainfall and more extreme storms could mean billions of dollars-worth of damage in the U.S. Flooding in particular has the capacity to destroy homes and communities. Hurricane Katrina, for example, killed more than 1,800 people and caused $125 billion worth of damage--most of it due to the storm surge.

The latest study highlights the importance of preparing for these future storms. This includes everything from making infrastructure more flood-resistant to building in areas where these storms are less likely to have a major impact.

The findings are published in the journal Geophysical Research Letters.