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Opinion Another monster hurricane season looms as we dawdle on climate change

Rising water from Hurricane Harvey pushed thousands of people to rooftops or higher ground in Houston on Aug 27, 2017. (Jabin Botsford/The Washington Post)

The National Oceanic and Atmospheric Administration has forecast that the coming hurricane season will see 14 to 21 named storms — and three to six Category 3 or above. This would be yet another in a series of abnormal seasons.

Scientists are only just coming to grips with the monster storm seasons of the recent past. The 2020 one brought a record 30 named storms to the North Atlantic, including 12 that hit the United States, causing some $40 billion in damage. A recent study published in the journal Nature Communications finds that climate change made these storms far worse than they would have been without human-caused global warming.

Predicting climate change’s effects on hurricanes has long been controversial. It is unclear, for example, just how rising world temperatures might alter the frequency of these battering storms, a fact that deniers of climate change often cite in their effort to play down its risks. But there is increasingly little doubt that human-caused warming is heating ocean-surface temperatures, which fuel big storms. The result appears to be stronger hurricanes.

Researchers from Lawrence Berkeley National Laboratory, Pennsylvania State University and Stony Brook University examined the entire 2020 season, during which human-caused warming increased average North Atlantic sea-surface temperatures by 0.6 degrees Celsius. They mapped out how the hurricane season would have proceeded without climate change and compared it to what happened. The three-hour extreme rainfall rate was 11 percent higher than it would have been absent climate change, they found, and the three-day extreme rainfall accumulation total was 8 percent higher. In other words, the storms dumped more water, and faster.

The study’s authors noted that their results are just one indication that climate change is worsening hurricane strength in a variety of ways. For example, wind speed might also be increasing, they suggested. But just more and more rapid rainfall is enough for concern, as anyone in New Orleans in 2005 or Houston in 2017 could tell you.

No government program or international accord will stop hurricanes from worsening. Humans have already pumped so many greenhouse gas emissions into the air and the world economy is still so dependent on fossil fuels that further warming is inevitable. The task is twofold. First, governments must try to prevent a bad situation from becoming even worse by forcing long-term cuts in polluting fuels, in the hope that warming can be kept under 1.5 degrees Celsius — or at least not too far over that threshold.

Congress must act on major climate legislation. In the meantime, governments must prepare for the impacts that are already in the pipeline. Coastal communities must invest in flood resilient infrastructure that they never needed before. Some will have to make tough choices about what is worth saving and what they will surrender to rising seas and floodwaters. Other areas of the country will need new strategies to cope with vicious storms, droughts and wildfires. Humanity cannot afford to dawdle.