‘100-Year Storms’ May Happen Every 3 to 20 Years

Last August, Hurricane Irene spun through the Caribbean and parts of the eastern United States, leaving widespread wreckage in its wake. Many hurricane analysts suggested, based on the wide extent of flooding, that Irene was a “100-year event”: a storm that only comes around once in a century.

However, researchers from MIT and Princeton University have found recently that with climate change, such storms could make landfall far more frequently, causing powerful, devastating storm surges every three to 20 years. The group simulated tens of thousands of storms under different climate conditions. The group looked at the impact of climate change on storm surges, using New York City as a case study.

Today, a “100-year storm” means a surge flood of about two meters, on average, in New York. But with added greenhouse gas emissions, the simulated storm models showed that a two-meter surge flood would instead occur once every three to 20 years; a three-meter flood would occur every 25 to 240 years. The researchers published their results in the latest issue of Nature Climate Change.