Restoring Florida’s fragile Everglades can help stem the greenhouse gas emissions that are warming the global climate and contributing to hotter temperatures, rising seas and more damaging storms in this particularly vulnerable state, new research has found.
The research, published last month in the Proceedings of the National Academy of Sciences, shows the freshwater marshes and coastal mangroves of the river of grass absorb some 14 million tons of climate-heating carbon dioxide annually from the Earth’s atmosphere. That amount is equal to 10 percent of the emissions coming from Florida roadways, said John Kominoski, a professor in the Institute of Environment at Florida International University and a researcher on the study.
“It’s almost like an investment in your retirement fund. You start to put it away slowly, and you don’t really understand the benefits,” said Kominoski, principal investigator of the federally supported Florida Coastal Everglades Long Term Ecological Research Program. “But over time the benefits emerge, and they are more than the sum of their parts. And that’s kind of what climate mitigation and climate sequestration are doing, not just locally, not just in the Everglades but across the world.”
The study concluded that carbon sequestration in the Everglades increased between 2003 and 2020 by 18 percent. The watershed is responsible for the drinking water of millions of Floridians and spans much of the state, encompassing the Kissimmee River, Lake Okeechobee, sawgrass marshes to the south and Florida Bay, at the peninsula’s southernmost tip. A $27 billion restoration effort is among the most ambitious of its kind in human history. The findings suggest improved freshwater flows that have resulted from restoration also have boosted the river of grass’ capability to draw carbon from the atmosphere, said Tiffany Troxler, associate professor in the Department of Earth and Environment at Florida International University and another researcher on the study.
“Most of the drinking water in the state of Florida comes from the Everglades,” she said. “If all of that wasn’t great enough, it also is an effective carbon sink.”
Wetlands store a lot of carbon in their soils, prompting scientists to investigate their potential as a nature-based solution to the fossil fuel emissions that have accelerated the planet’s warming since the industrial age, leading to more extreme disasters such as hurricanes and wildfires.
An interdisciplinary team of scientists from East Carolina University, Florida International University, the NASA Goddard Space Flight Center, the University of Alabama, the University of Maryland and Yale University joined to conduct the study. The researchers wanted to understand how human interference, along with environmental pressures such as sea level rise and storms, can affect the way wetlands interact with carbon. They focused on the Everglades because the watershed is among the most altered on Earth, after a series of historic efforts to drain the peninsula and modernize the state. Restoration is aimed at reviving the river of grass’ natural flow and securing the drinking water supply for the future in this fast-growing region.
The researchers’ conclusions were based on data collected from AmeriFlux towers in Everglades National Park and the Big Cypress National Preserve, part of a network of monitoring sites throughout the Americas. The scientists also relied upon atmospheric carbon measurements NASA gathered by plane. They combined the data with satellite measurements of vegetation changes to create a model that could estimate carbon fluctuations across the study area.
The picture that developed based on the data was complicated. While the researchers confirmed the Everglades are an important carbon sink, they discovered that its coastal mangroves are more effective at trapping carbon than freshwater marshes. The river of grass is composed of a mosaic of freshwater marsh sloughs, tree islands, forested cypress swamps and hardwood hammocks, framed by coastal mangroves and brackish swamps.
Even as the Everglades absorb carbon, the watershed emits methane, a potent greenhouse gas that accounts for 30 percent of the planet’s warming since industrialization. Methane, which can be produced by microbes in oxygen-poor soils, traps 80 times more heat in the atmosphere than carbon dioxide over a 20-year period.
The researchers found that while carbon sequestration increased in the Everglades between 2003 and 2020, nearly 82 percent of the amount stored in the freshwater marshes was offset by net methane emissions. That compares with 18 percent in the coastal mangroves. The findings can help guide future restoration efforts and water management strategies, the scientists said.
“What we found was that restoration is very important for hydrating the Everglades, but it comes at a greenhouse gas cost,” Kominoski said. “Our wetlands are working as net carbon sinks, removing more carbon than they are emitting, but unfortunately some of them are hotspots of methane flux and at times carbon dioxide flux. And so these are systems that need to be protected, restored and maintained as best we can to continue to increase carbon removal, and they are removing more carbon than they are emitting.”
About This Story
Perhaps you noticed: This story, like all the news we publish, is free to read. That’s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.
That’s not all. We also share our news for free with scores of other media organizations around the country. Many of them can’t afford to do environmental journalism of their own. We’ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible.
Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action.
Donations from readers like you fund every aspect of what we do. If you don’t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places?
Please take a moment to make a tax-deductible donation. Every one of them makes a difference.
Thank you,
Amy Green
Reporter, Florida
Amy Green covers the environment and climate change from Orlando, Florida. She is a mid-career journalist and author whose extensive reporting on the Everglades is featured in the book MOVING WATER, published by Johns Hopkins University Press, and podcast DRAINED, available wherever you get your podcasts. Amy’s work has been recognized with many awards, including a prestigious Edward R. Murrow Award and Public Media Journalists Association award.
