By Paul Sutton, University of Denver
While climate change did not create damaging weather and wildfires, it has demonstrably made them more extreme and punishing. There is a credible foreboding among many South Floridians as we enter the 2021 hurricane season.
Since 1851, 120 hurricanes — more than 41% of the hurricanes that have hit the U.S. — made some sort of landfall in Florida, with Miami-Fort Lauderdale-West Palm Beach the most susceptible area.
Today, as climate change advances, the Earth has heated up and is producing rising sea levels and warmer oceans. During the past 20 years, that has triggered even more severe and frequent storms.
The coastal communities in southeast Florida that have grown among the wetlands and barrier islands that can buffer against storm damages are facing serious questions about how to address the storms.
Do they build massive seawalls to protect our infrastructure? Do they give up on coastal location and retreat inland? One solution floated in June by the Army Corps of Engineers was to build a giant seawall running through Biscayne Bay and parts of Miami-Dade County. On Monday the county commission said it would not support the wall.
Recently a new study revealed more expansively than ever the promise of nature itself — healthy coastal wetlands — to avoid damages and save lives. The accuracy of the study’s findings takes advantage of state-of-the-art storm tracking, enhanced global land use mapping and global damage assessment databases, along with improved computational capabilities.
The researchers used the historical tracks of over 1,000 tropical cyclones since 1902 that recorded property damage and/or human casualties in 71 countries/regions and found that an estimated $450 billion in economic damage would be prevented by coastal wetlands mitigating the effect of tropical storms and 4,600 lives would be saved every year. The United States would save $200 billion in annual damages and save 469 lives because of wetlands, according to the study.
The way that coastal wetlands work is to protect shorelines with “horizontal levees” that are maintained by nature and are far more cost-effective than constructed levees or seawalls. The wetlands decrease the area of open water for wind to form waves and increases drag on water motion. That reduces storm surge.
Coastal wetlands also provide other valuable ecosystem services that constructed seawalls do not, such as nursery habitat for marine species, recreational opportunities, and management of sediment and nutrient runoff.
But changes in land use, which includes the loss of coastal wetlands, are reducing the value of the ecosystem services they can provide. Since 1900, the world has lost over half of its wetlands. The new data shows that reversing this trend and investing in the maintenance and restoration of coastal wetlands is extremely cost-effective.
And in the larger picture, they can increase well-being for humans and the rest of nature. Indeed, the emerging evidence shows our economy, our lives and our very civilization depend on a healthy planet and functioning ecosystems.
The frequency and intensity of tropical cyclones and other extreme weather events in recent decades is increasing.
As Florida (and the world) considers solutions to protect lives and property from the onslaught of coastal storms, much larger investments in the conservation and restoration of coastal wetlands and other natural ecosystems are deserve our life-saving attention.
Paul Sutton is a professor in the Department of Geography and the Environment at the University of Denver. He co-authored the paper “The global value of coastal wetlands for storm protection” as part of a team of scientists from all over the world, including Florida.
“The Invading Sea” is the opinion arm of the Florida Climate Reporting Network, a collaborative of news organizations across the state focusing on the threats posed by the warming climate.