Previous attribution studies have quantified the effects of climate change on individual Atlantic storms: For example, researchers estimate that up to 38 percent of the extreme rainfall that Hurricane Harvey dumped in southeastern Texas in August 2017 was due to climate change. dr. Reed was among 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 just the storms that make headlines, but the seemingly regular storms as well. dr. Reed said the findings provided strong evidence that the anthropogenic impact was not an anomaly limited to major events like Harvey.
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“If you do this lens for a whole season, you get similar results,” he said.
Rosimar Rios-Berrios, a research meteorologist at the National Center for Atmospheric Research who was not involved in the new study, said examining an entire hurricane season rather than individual storms provided a higher degree of confidence that the findings accurately determine the role of climate. reflected Change.
“There’s a lot of power in studying individual events, but ultimately a single event isn’t enough because every hurricane is different,” she said.
A separate analysis released Monday found that climate change most likely also increased rainfall intensity from two vicious tropical storms that ravaged southeast Africa earlier this year. But the researchers said that due to a shortage of high-quality weather data for that region, they were unable to measure the precise impact of global warming on those storms.
dr. Reed noted that the same method his team used could be used to quantify the impact of climate change on a storm in near real time — or to illustrate how much worse storms will get if countries continue to burn fossil fuels.
The study published Tuesday compared the 2020 hurricane season as we experienced it to the hypothetical 2020 hurricane season in a world that has not been warmed by human activity. Since the 19th century, the combustion of oil, gas and coal has increased the average temperature on Earth by 1.1 degrees Celsius or 2.7 degrees Fahrenheit. It’s also possible to compare the season as experienced with the version that can occur after, say, 1.5 or 2 degrees of warming — the threshold above which scientists say highly destructive storms become significantly more likely.
“It’s important not to plan ahead for the 2020 hurricane season,” said Dr. Drove. “It’s to plan for what the 2020 hurricane season plus climate change would look like in the future.”
Raymond Zhong contributed reporting.