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New projection: Faster rising seas forecast in South Florida

Water floods part of a street that runs near the Strait of Florida during the seasonal king tides on October 26, 2019 in Key West.
Water floods part of a street that runs near the Strait of Florida during the seasonal king tides on October 26, 2019 in Key West. (Photo by Joe Raedle/Getty Images)

KEY WEST, Fla. – New scientific projections released Wednesday predict that ocean levels will rise even faster than previously forecast over the next four decades in low-lying southeastern Florida, which is already prone to frequent flooding even on sunny days.

Compared with estimates made in 2015, the new prediction is for about 5 inches in additional sea level rise under a moderate outlook by 2060. The projection was released as part of a meeting of the Southeast Florida Climate Leadership Summit, which covers densely populated Miami-Dade, Broward, Palm Beach and Monroe counties.

About 3 inches of rising seas have already occurred between 1992 and 2019 in the region, according to the new study. It’s become common at high tides — especially the most robust king tides — to flood roads, parks, yards and structures as the water continues to creep upward. Sometimes the water pushes up through inland stormwater systems.

“This is what gets people freaking out,” said Gus Zambrano, assistant manager for the City of Hollywood. “It’s a wake-up call.”

The previous overall estimate for sea level rise affecting the region called for about 2 feet higher in 2060 than water levels generally were in 2000. Now, the forecast calls for almost 2.5 feet of encroaching water over that time span.

Jayantha Obeysekera, director of the Sea Level Solutions Center at Florida International University and one scientist involved in the new projections, said the key variable will be whether an increasingly warming planet undergoing climate change will cause ice sheets in Greenland and Antarctica to melt more rapidly than previously thought. Other factors are rising ocean temperatures and changes in currents such as a slowing Gulf Stream.

“This is the latest, best available science,” Obeysekera said in an interview at the climate summit in Key West. “We have multiple scenarios based on the melting of ice.’”

The projection included input from about a dozen scientists, local government staff experts and officials from the National Oceanic and Atmospheric Administration.

Although the latest projected increase may seem minimal, already governments in the South Florida region are spending hundreds of millions of dollars — with much more to come — on everything from giant water pumps to new sea walls to raising roadways to more innovative approaches such as creating living shorelines that use plants and natural features to keep the water at bay.