Hurricane Florence will dump up to 50 percent more rainfall due to climate change

In recent years, after most major natural disasters, scientists have worked to understand what effects, if any, can be attributed to climate change.

These reports, called attribution studies, can take months to compile. For Hurricane Florence, a massive storm barreling towards the Carolina coast, scientists did the math ahead of time.

And yes, climate change is making Hurricane Florence worse. Much worse.

A group of scientists from Stony Brook University, Lawrence Berkeley National Laboratory, and the National Center for Atmospheric Research have created the first pre-event attribution statement, comparing the forecasted intensity of Hurricane Florence to the same hurricane forecast “if it were to occur in a world without human-induced global warming.”

Stony Brook University’s School of Marine and Atmospheric Sciences

According to the study, rainfall amounts from Hurricane Florence will be up to 50 percent higher, while the size of the storm itself—and it’s an exceptionally large storm—will be about 50 miles wider due the effect of climate change. Additionally, the storm will remain at a higher category for a longer duration of time.

While not all extreme weather is caused or exacerbated by climate change, atmospheric scientists can look for “signals” in specific weather events to tie them to a warming planet. Larger storms and heavier downpours are both strong signals because higher sea surface temperatures mean more water vapor will be absorbed by the atmosphere.

Attribution research has been crucial in recent years as local leaders have had to grapple with some of the country’s deadliest and most destructive wildfires, floods, and hurricanes. Last year, the country suffered a record-breaking number of billion-dollar disasters, with economic losses topping an astounding $400 billion. In addition, researchers have now estimated that Hurricane Maria killed about 3,000 people—making it one of the deadliest natural disasters in U.S history.

Attribution studies can also help cities modify their disaster response plans. Especially in places which have not experienced these types of events before, knowing that record-breaking rainfall is more likely than a storm surge, for example, can help the region plan specific evacuation strategies that might focus on inland rivers in addition to coastal flooding. And understanding that storms will be larger and more powerful in the future can inform rebuilding efforts after the hurricane has passed, even when the current administration has loosened building regulations in flood-prone areas.

As President Trump’s tweets blame fire damage on environmentalists and deny the death toll in Puerto Rico, it’s clear that U.S. cities will have to rely on data from scientists, not the federal government, to make smart decisions about their futures.

Last year, Hurricane Harvey broke the single-storm rainfall total in the U.S. with 51.88 inches recorded in parts of Houston. That was a year’s worth of rain falling in a 72-hour period—an event so unprecedented that even the forecast said “all impacts are unknown.”

Studying the effects of climate change is no longer about predicting variables sometime in the distant future. This type of science can save lives this week.