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Sawgrasses and lilies in the Everglades.
Mac Stone

Sawgrasses and lilies in the Everglades, a complex region of tropical wetlands that has been drained to make way for sugarcane and development for more than 125 years. Ranking with the Camargue in France and the Pantanal in South America as one of the greatest wetlands in the world, it is a rain-fed grassland on a limestone shelf. Slow-moving water moves through grasses to remove pollutants, making it a highly effective water treatment system. In 2000, following an act of Congress, the most expensive and complex environmental restoration in human history began and continues to this day despite constant political resistance.

Coastal Wetland Protection

Reduce SourcesFood, Agriculture, and Land UseProtect Ecosystems
Support SinksCoastal and Ocean SinksProtect and Restore Ecosystems
0.99–1.45
Gigatons
CO2 Equivalent
Reduced / Sequestered
(2020–2050)
Mangroves, salt marshes, and seagrasses sequester huge amounts of carbon in plants and soil. Protecting them inhibits degradation and safeguards their carbon sinks.

Solution Summary*

Along the fringes of coasts, where land and ocean meet, lie the world’s salt marshes, mangroves, and sea grasses. These coastal wetland ecosystems are found on every continent except Antarctica.

They provide nurseries for fish, feeding grounds for migratory birds, a first line of defense against storm surges and floodwaters, and natural filtration systems that boost water quality and recharge aquifers. Relative to their land area, they also sequester huge amounts of carbon in plants aboveground and in roots and soils below.

Coastal wetlands can store five times as much carbon as tropical forests over the long term, mostly in deep wetland soils. The soil of mangrove forests alone may hold the equivalent of more than two years of global emissions—22 billion tons of carbon, much of which would escape if these ecosystems were lost.

Wetlands face a myriad of threats, but thanks to research and advocacy efforts, awareness is growing about the role they play in curbing climate change and coping with its impacts. It is vital to preserve healthy coastal wetlands—keeping a lid on the carbon they contain—while also rehabilitating and restoring those that already have been degraded. 

* excerpted from the book, Drawdown
Impact:

Of the 53.2 million hectares of coastal wetlands globally, 12.6 million hectares are protected today. If an additional 17.4-22.1 million hectares are protected by 2050, the resulting avoided emissions and continued sequestration could total 0.99-1.5 gigatons of carbon dioxide. While limited in area, coastal wetlands contain large carbon sinks; protecting them would secure an estimated 10.6-12.1 gigatons of carbon, equivalent to over 38.9-44.4 gigatons of carbon dioxide if released into the atmosphere.