Previous attribution studies have quantified the effects of climate change on individual Atlantic storms: For example, researchers estimated that up to 38 percent of the extreme rainfall that Hurricane Harvey dumped in southeast Texas August 2017 was due to climate change. Dr. Reed was one of the researchers who confirmed that climate change also played a role in Hurricane Florence in 2018 and Hurricane Dorian in 2019.
The new study is unusual in that it examined the effects of climate change not on a single hurricane, but on an entire hurricane season, including not only the storms that hit the headlines, but also the seemingly normal ones. Dr. Reed said the findings provided strong evidence that anthropogenic impact was not an anomaly limited to major events like Harvey.
Understand the latest news on climate change
“If you do it objectively for an entire season, you get similar results,” he said.
Rosimar Rios-Berrios, a meteorologist at the National Center for Atmospheric Research who did not participate in the new study, said examining a full season of hurricanes instead of individual storms provided a higher degree of confidence than the findings accurately reflected the role of climate. exchange.
“There’s a lot of power in studying individual events, but in the end, a single event isn’t enough because every hurricane is different,” he said.
A separate analysis released on Monday found that climate change also likely increased the intensity of the rains of two vicious tropical storms that hit southeast Africa earlier this year. But researchers said that due to the scarcity of high-quality meteorological data for this region, they were unable to measure the precise influence of global warming on these storms.
Dr. Reed noted that the same methodology used by his team could be used to quantify the impact of climate change on a near-real-time storm, or to illustrate how much worse storms will be if nations continue to burn fuel. fossils.
The study published on Tuesday compared the 2020 hurricane season as we experienced it with the hypothetical 2020 hurricane season in a world that has not been warmed by human activities. Since the 19th century, the combustion of oil, gas, and coal has increased the average global temperature by 1.1 degrees Celsius, or 2 degrees Fahrenheit. It is also possible to compare the season as experienced with the version that can occur after, for example, 1.5 or 2 degrees Celsius warming, the threshold beyond which scientists say storms highly destructive are much more likely.
“It’s important not to plan for the 2020 hurricane season in the future,” Dr. Reed. “It’s about planning what the 2020 hurricane season and climate change will look like in the future.”
Raymond Zhong provide reports.