Rain expected during Hurricane Florence, rain without climate change

Rain expected during Hurricane Florence (left) versus rain without climate change. Stony Brook University/Provided 

Four years, four rain bombs in the Carolinas: A growing number of studies say human-caused climate change is making storms worse, with one research team finding half of Florence’s expected rain was caused by a rapidly warming planet.

Florence made landfall Friday morning as a Category 1 hurricane but was later downgraded to a tropical storm.

Global temperatures have risen more than 1 degree since 1921, a small increase with big ramifications. Warmer air holds more moisture, and when water falls as rain, it releases energy in the form of heat. This adds even more fuel to storms.

Recent studies showed that climate change increased Hurricane Harvey's record-breaking rain by as much as 38 percent. More than 50 inches fell when the storm stalled over Houston.

Kevin Reed, an atmospheric scientist at Stony Brook University and study co-author, said his team used similar methods as those in the Harvey findings.

But instead of running analyses after the storm, his team used them before. The team's calculations were tied in part to rising sea temperatures — increases stemming largely from humanity's burning of fossil fuels.

He said he wasn't so surprised at the 50 percent finding, given the research into Harvey, but it was sobering nonetheless.

He added that Florence’s massive wind field was about 40 miles wider than it would have been without human-induced climate change. 

His team’s work echoes other studies.

The Southeast already has experienced a 27 percent increase in the number of downpours since 1958, one study found. 

In another, Andra Reed, a Penn State meteorologist, found that in 2015, Hurricane Joaquin grew quickly because of extremely warm sea surface temperatures.

The air filled with ever-greater amounts of moisture and then unleashed it over the Carolinas, triggering what then-Gov. Nikki Haley described as a “1,000-year flood.”

That flood dumped more than 23 inches on the Charleston peninsula. In 2016, Hurricane Matthew poured 18 inches in some parts of the Carolinas. And in 2017, Irma flooded Charleston with a 4-foot surge; 9 inches of rain fell in Beaufort and more than 20 inches in part of Florida. 

Reed also co-authored a study that looked at New York’s history of torrential rains and floods.

By examining microorganisms left behind in sediment, they identified significant flooding events. Plugging this data into increasingly sophisticated climate models yielded a stunning result: New York will likely see “500-year flood heights” every 24 years.

Reach Tony Bartelme at 843-937-5554. Follow him on Twitter @tbartelme.

Tony Bartelme is senior projects reporter for The Post and Courier. He has earned national honors from the Nieman, Scripps, Loeb and National Press foundations and is a three-time finalist for the Pulitzer Prize. Reach him at 843-937-5554 and @tbartelme