NASA Researchers Study Coastal Wetlands, Champions of Carbon Capture

NASA, March 13, 2025

A mangrove “ghost forest” near Florida’s southernmost coast houses the remains of a once-thriving mangrove stand. Credits: NASA/Nathan Marder

Please Note: The following is an excerpt. To view the entire article by NASA, click the link at the end of this blog.

Across the street from the Flamingo Visitor’s Center at the foot of Florida’s Everglades National Park, there was once a thriving mangrove population — part of the largest stand of mangroves in the Western Hemisphere. Now, the skeletal remains of the trees form one of the Everglades’ largest ghost forests.

When Hurricane Irma made landfall in September 2017 as a category 4 storm, violent winds battered the shore and a storm surge swept across the coast, decimating large swaths of mangrove forest. Seven years later, most of the mangroves here haven’t seen any new growth. “At this point, I doubt they’ll recover,” said David Lagomasino, a professor of coastal studies at East Carolina University.

Lagomasino was in the Everglades conducting fieldwork as part of NASA’s BlueFlux Campaign, a three-year project that aims to study how sub-tropical wetlands influence atmospheric levels of carbon dioxide (CO2) and methane. Both gases absorb solar radiation and have a warming effect on Earth’s atmosphere.

The campaign is led by Ben Poulter, a researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who studies the way human activity and climate change affect the carbon cycle. As wetland vegetation responds to increasing temperatures, rising sea levels, and severe weather, Poulter’s team is trying to determine how much carbon dioxide wetland vegetation removes from the atmosphere and how much methane it produces. Ultimately this research will help scientists develop models to estimate and monitor greenhouse gas concentrations in coastal areas around the globe.

Lagomasino holds a sample of peat soil collected from the forest floor. The source of the soil’s elevated carbon content — evident from its coarse, fibrous texture — is primarily the thread-like root hairs routinely recycled by the surrounding mangroves. The presence of water slows the decomposition of this organic material, which is why wetlands can lock carbon away and prevent it from escaping into the atmosphere for thousands of years. Credits: NASA/Nathan Marder

Although coastal wetlands account for less than 2% of the planet’s land-surface area, they remove a significant amount of carbon dioxide from the atmosphere. Florida’s coastal wetlands alone remove an estimated 31.8 million metric tons each year. A commercial aircraft would have to circle the globe more than 26,000 times to produce the same amount of carbon dioxide. Coastal wetlands also store carbon in marine sediments, keeping it underground — and out of the atmosphere — for thousands of years. This carbon storage capacity of oceans and wetlands is so robust that it has its own name: blue carbon.

“We’re worried about losing that stored carbon,” Poulter said. “But blue carbon also offers tremendous opportunities for climate mitigation if conservation and restoration are properly supported by science.”

The one-meter core samples collected by Lagomasino will be used to identify historic rates of blue carbon development in mangrove forests and to evaluate how rates of carbon storage respond to specific environmental pressures, like sea level rise or the increasing frequency of tropical cyclones.

Early findings from space-based flux data confirm that, in addition to acting as a sink of carbon dioxide, tropical wetlands are a significant source of methane — a greenhouse gas that traps heat roughly 80 times more efficiently than carbon dioxide. In fact, researchers estimate that Florida’s entire wetland expanse produces enough methane to offset the benefits of wetland carbon removal by about 5%.

[Cont'd] The future of South Florida’s ecology

Florida’s wetlands are roughly 5,000 years old. But in just the past century, more than half of the state’s original wetland coverage has been lost as vegetation was cleared and water was drained to accommodate the growing population. The Everglades system now contains 65% less peat and 77% less stored carbon than it did prior to drainage. The future of the ecosystem — which is not only an important reservoir for atmospheric carbon, but a source of drinking water for more than 7 million Floridians and a home to flora and fauna found nowhere else on Earth — is uncertain.

Scientists who have dedicated their careers to understanding and restoring South Florida’s ecology are hopeful.

“Nature and people can coexist,” said Meenakshi Chabba, an ecologist and resilience scientist at the Everglades Foundation in Florida’s Miami-Dade County. “But we need good science and good management to reach that goal.”

The next step for NASA’s BlueFlux campaign is the development of a satellite-based data product that can help regional stakeholders evaluate in real-time how Florida’s wetlands are responding to restoration efforts designed to protect one of the state’s most precious natural resources — and all those who depend on it.

Read NASA's article here: https://science.nasa.gov/earth/nasa-researchers-study-coastal-wetlands-champions-of-carbon-capture/