A new study has found that heavy rainstorms will increase significantly by the end of the century.
The study, published in the journal Geophysical Research Letters, is the first of its kind to focus on the heaviest rain and snowstorms. It adds to previous studies which have already confirmed that extreme precipitation is becoming more common, and warns engineers and planners to think of such extreme events when planning infrastructure.
“We looked very specifically at the biggest storms,” said Kenneth Kunkel, a senior research professor at North Carolina State University’s Cooperative Institute for Climate and Satellites and lead author of the study. “What we’re saying is the big event on the extreme tail of the distribution . . . that event is likely to be bigger by the end of this century; quite a bit bigger.”
Climate Central writes:
The study examined changes in what is known as the “potential maximum precipitation,” which is the maximum amount of precipitation that is “potentially possible” in a particular area given ideal conditions.
That calculation is not something that will be familiar to viewers of the daily TV weather report, but it helps engineers guide infrastructure planning for dams and other water management structures, many of which are constructed to last 50 to 100 years. Many of the dams and levees in use today along the Mississippi River were designed in the early 1900s, for example.
The paper looked at three factors that can affect the potential maximum precipitation: the amount of moisture, or water vapor, in the atmosphere, the vertical motion of air, and horizontal winds. The researchers used climate models to simulate how increasing amounts of greenhouse gases in the atmosphere, such as carbon dioxide, would alter those factors. Kunkel said the researchers were particularly interested in seeing whether the other factors would offset the influence of the already observable upward trend in water vapor.
The study found just the opposite — the only factor that will change significantly in a warming world is the maximum moisture in the air, and it won’t be counterbalanced by changes in the other variables.
Most people can attest that extreme weather is becoming a norm, and this new finding suggests that we need to accept the change and build our community accordingly to compensate for such extreme weather.