Previous attribution studies have identified the effects of climate change on individual Atlantic storms: For example, researchers estimated that up to 38 percent of Hurricane Harvey’s heavy rain in southeast Texas in August 2017 was attributable to climate change. Dr. Reed was among the researchers confirming 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 dominate the headlines but also seemingly ordinary storms. Dr. Reed said the findings provided strong evidence that human influence was not an anomaly confined to massive events like Harvey’s.
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“If you do this objectively over the course of an entire season, you will get similar results,” he said.
Examining an entire hurricane season rather than individual storms provides a higher degree of confidence that the results accurately reflect the role of climate, said Rosimar Rios-Pereus, a meteorologist at the National Center for Atmospheric Research who was not involved in the new study. they change.
“There is a great deal of power in studying individual events, but in the end, one event is not enough because every hurricane is different,” she said.
And a separate analysis released Monday found that climate change likely also increased the intensity of rainfall from two vicious tropical storms that hit southeast Africa earlier this year. But the researchers said that due to a lack of high-quality weather data for that region, they were unable to measure the exact impact of global warming on those storms.
Dr. Reed noted that the same methodology his team used could be used to quantify the impact of climate change on a storm in near real time — or to show how bad storms would be if nations continued to burn fossil fuels.
The study published Tuesday compared the 2020 hurricane season we experienced with the hypothetical 2020 hurricane season in a world not warmed by human activities. Since the 19th century, burning oil, gas, and coal has increased average global temperatures by 1.1 degrees Celsius, or two degrees Fahrenheit. It is also possible to compare the season as with the release that might occur after, say, 1.5 or 2°C of warming – the threshold beyond which scientists say highly destructive storms become significantly more likely.
“It is important not to plan for the 2020 hurricane season in the future,” said Dr. Reed. “It’s planning for what the 2020 hurricane season will look like as well as future climate change.”
Raymond Chung Contribute to the preparation of reports.