Hurricanes have grown stronger over the last four decades—and climate change is likely to blame, says a new study from the National Oceanic and Atmospheric Administration and the Cooperative Institute for Meteorological Satellite Studies.

Scientists looked at global hurricane satellite imagery taken from 1979-2017, using techniques like infrared temperature measurements from geostationary satellites to estimate hurricane intensity. Over the study period, about 225,000 intensity estimates were available for about 4,000 individual tropical cyclones worldwide.

The study found that the likelihood of a storm becoming a major tropical cyclone—Category 3-5 on the Saffir-Simpson scale, with wind speeds 111 mph or higher—increased approximately 8 percent per decade. Regionally, the North Atlantic, along the U.S. eastern seaboard, showed the greatest changes, with the probability of a hurricane becoming major increasing a whopping 49 percent per decade.

“The main hurdle we have for finding trends is that the data are collected using the best technology at the time,” said James Kossin, a NOAA scientist based at UW-Madison and lead author of the paper,published in the Proceedings of the National Academy of Sciences. “Every year the data are a bit different than last year, each new satellite has new tools and captures data in different ways, so in the end we have a patchwork quilt of all the satellite data that have been woven together.”

Source: University of Wisconsin-Madison