The analysis of four decades of satellite imagery has revealed that hurricanes are getting stronger. Led by the University of Wisconsin-Madison, a team of researchers found that the maximum sustained winds associated with hurricanes are intensifying, and global warming is to blame.
“Through modeling and our understanding of atmospheric physics, the study agrees with what we would expect to see in a warming climate like ours,” said study lead author and NOAA scientist James Kossin.
In a 2013 study, Kossin and his colleagues identified trends in hurricane strengthening based on data from 28 years. According to Kossin, the findings were less conclusive and required further research.
For the current study, the researchers focused on global hurricane data from 1979 to 2017. The team was able to create a more uniform dataset to clearly identify trends.
“The main hurdle we have for finding trends is that the data are collected using the best technology at the time,” said Kossin.
“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.”
Kossin has previously documented additional variations in hurricane behavior that have emerged over the decades, such as the location and speed of the storms.
In 2014, he identified poleward migrations of hurricanes, where tropical cyclones are traveling farther north and south, placing new coastal populations at a higher risk of impact.
In 2018, Kossin demonstrated that hurricanes are moving more slowly across land due to changes in the climate. This leads to greater flooding dangers as the storms hover over populated areas for extended periods of time.
“Our results show that these storms have become stronger on global and regional levels, which is consistent with expectations of how hurricanes respond to a warming world,” said Kossin.
“It’s a good step forward and increases our confidence that global warming has made hurricanes stronger, but our results don’t tell us precisely how much of the trends are caused by human activities and how much may be just natural variability.”
The study is published in the journal PNAS.
By Chrissy Sexton, Earth.com Staff Writer