Why wetlands are important.
Wetlands are an essential ecosystem that promote biodiversity and flood control. Like forests, they are an integral part of the carbon-sink. They are also essential to maintaining a livable climate – their destruction potentially accelerates global warming.  Covering just 6% of Earth’s land surface, wetlands(including marshes, peat bogs, swamps, river deltas, mangroves, tundra, lagoons and river floodplains) store 10-20% of its terrestrial carbon.  Some 60% of wetlands worldwide, and up to 90% in Europe  have been destroyed in the past 100 years, principally due to drainage for agriculture but also through pollution, dams, canals, groundwater pumping, urban development and peat extraction. link   



  • What are wetlands
  • A “Carbon Bomb”
  • Florida Everglades
  • Wetlands in the USA
  • Around the world
What are wetlands

What are wetlands? 
Generally, wetlands are lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. Wetlands’ microbes, plants, and wildlife are part of global cycles for water, nitrogen, and sulfur. Furthermore, scientists are beginning to realize that atmospheric maintenance may be an additional wetlands function. Wetlands store carbon within their plant communities and soil instead of releasing it to the atmosphere as carbon dioxide. Thus wetlands help to moderate global climate conditions.

Part of their function is helping to control floods and prevent water logging of crops. The bottomland hardwood-riparian wetlands along the Mississippi River once stored at least 60 days of floodwater. Now they store only 12 days because most have been filled or drained.
The ability of wetlands to control erosion is so valuable that some states are restoring wetlands in coastal areas to buffer the storm surges from hurricanes and tropical storms. Wetlands at the margins of lakes, rivers, bays, and the ocean protect shorelines and stream banks against erosion. Wetland plants hold the soil in place with their roots, absorb the energy of waves, and break up the flow of stream or river currents. link

September 2018: Wetlands disappearing three times faster than forests. An 88-page report found that around 35% of wetlands, which include lakes, rivers, marshes and peatlands, as well as coastal and marine areas like lagoons, mangroves and coral reefs, were lost between 1970 and 2015. Wetlands, among the world’s most valuable and biodiverse ecosystems, are disappearing at alarming speed amid urbanisation and agriculture shifts and conservationists are calling for urgent action to halt the erosion. link

January 2018: Blue carbon discovery. Over the past decade, scientists and policymakers have pushed to protect the carbon stored in coastal wetlands, known as blue carbon. Whether it’s a mangrove forest in Florida, a freshwater swamp in Virginia or a saltwater marsh in Oregon, the amount of carbon locked in a soil sample from each of these coastal ecosystems is roughly the same. In terms of carbon stocks, all tidal wetlands are very, very similar The discovery could bolster efforts to assess and protect the world’s coastal wetlands. These ecosystems accumulate vast stocks of carbon that are released into the atmosphere when wetlands are destroyed. link

September 2017: Study – wetlands can significantly reduce property damage. The devastating impacts of this year’s storms across the United States and the Caribbean provide tragic reminders of the catastrophic risks faced on our coasts, which are being developed rapidly and intensely worldwide. Many cities and towns face the brunt of damage from hurricanes and are looking for better and cheaper ways to reduce their risks. Yet rapid coastal development is destroying natural ecosystems like marshes, mangroves and coral reefs – resources that help protect us from catastrophes. link

February 2017: Coastal wetlands excel at storing carbon. Recent research suggests that healthy, intact coastal wetland ecosystems such as mangrove forests, tidal marshes and seagrass meadows are particularly good at drawing carbon dioxide from the atmosphere and storing it for hundreds to thousands of years. link

July 2016: Restoring wetlands makes good economic sense. It’s well-established that wetlands offer considerable benefits for people and nature, including flood protection, pollution reduction and outdoor recreational opportunities. These benefits bring considerable economic value to our communities. link

July 2015: Swamp power: how the world’s wetlands can help stop climate change. Maintaining the wetland is key to reducing Europe’s carbon emissions. Peatland makes up just 3% of the continent’s agricultural land but, because of poor management and degradation, is responsible for more than 90% of CO2 emissions from farming. Globally, ‘paludiculture’ (literally, swamp cultivation) could also help to save the world’s disappearing peat swamp forests, which account for around 5% of global CO2 emissions, and an immeasurable loss in biodiversity. Peatland is waterlogged land with a 30cm top layer of decomposing plant material. link

“Fabulous Wetlands” video with Bill Nye. 1989 but still important today (7 minutes)

 World’s wetlands – a “Carbon Bomb”

The world’s wetlands, threatened by development, dehydration and climate change, could release a planet-warming “carbon bomb” if they are destroyed: Wetlands contain 771 billion tons of greenhouse gases, one-fifth of all the carbon on Earth and about the same amount of carbon as is now in the atmosphere.

December 2009: New program similar to REDD needed to store carbon in waters. Dan Laffoley, marine vice chairman of the World Commission on Protected Areas at the International Union for Conservation of Nature, argues countries should be encouraged to establish marine protected areas – that is, set aside parts of the coast and sea where nature is allowed to thrive without undue human interference – and do what they can to restore habitats like salt marshes, kelp forests and sea-grass meadows. In addition to producing most of the oxygen we breathe, the ocean absorbs some 25% of current annual carbon dioxide emissions. Half the world’s carbon stocks are held in plankton, mangroves, salt marshes and other marine life. So it is at least as important to preserve this ocean life as it is to preserve forests. link 

July 2008: Massive greenhouse gases may be released as destruction of world wetlands worsen. The world’s wetlands, threatened by development, dehydration and climate change, could release a planet-warming “carbon bomb” if they are destroyed, according to ecological scientists. If all the wetlands on the planet released the carbon they hold, it would contribute powerfully to the climate-warming greenhouse effect, said Paulo Teixeira, coordinator of the Pantanal Regional Environment Program in Brazil. “We could call it the carbon bomb,” Teixeira said:  “It’s a very tricky situation.” Wetlands are not just swamps: they also include marshes, peat bogs, river deltas, mangroves, tundra, lagoons and river flood plains. They also produce 25% of the world’s food, purify water, recharge aquifers and act as buffers against violent coastal storms. link

 Florida Everglades

Why the Florida Everglades are important. 

“The Everglades is a test.  If we pass we get to keep the planet.”  – Joe Podgor, Former Executive Director of Friends of the Everglades. The Everglades is already stressed as a result of the increased population of south Florida and dramatic changes to water supply and flow over the past 60 years. At the same time it is one of the most crucial habitats for threatened and endangered species such as the Florida panther, West Indian manatee, and the southern bald eagle. Florida is expected to be particularly affected by rising sea levels, making the restoration of the Everglades even more important for helping south Florida adapt to the effects of climate change. link

May 2018: Everglades under threat as Florida’s mangroves face death by rising sea level. Florida’s mangroves have been forced into a hasty retreat by sea level rise and now face being drowned, imperiling the prized Everglades wetlands. “There’s nowhere left for them to go,” said Dr. Randall Parkinson, a coastal geologist at FIU. “They are done. The sea will continue to rise and the question now is whether they will be replaced by open water. I think they will.” link

September 2017: Hurricanes taking toll on Everglades. Everglades National Park, 2,300 square miles of wetland area and a natural buffer against rising seas, is part of the freshwater system that feeds South Florida’s Biscayne Aquifer, a source of drinking water for millions of people. Hurricanes, in and of themselves, are not necessarily devastating events for the Everglades, and can even sometimes benefit the landscape by throwing mud onto the coast and helping to build up the land. Over the last century, however, sea-level rise, accelerated by human-induced global warming, has begun to degrade the Everglades by allowing salt water to seep into the system. link

November 2013: Everglades face ominous prospects from rising waters. The Everglades, the river of grass that gives the region its fresh water, could one day be useless, some scientists fear, contaminated by the inexorable advance of the salt-filled ocean. The Florida Keys would be mostly submerged. link

October 2011: As sea level rises, Everglades become more vital to south Florida’s survivalClimate change threatens every part of the U.S. in one-way or another, but in South Florida, it’s not just a threat: it’s a looming catastrophe. Much of the area lies just a few feet above sea level, and thanks to warming temperatures and melting polar ice, the sea is on the rise. A few decades from now, significant parts of the region could literally be underwater. Not only that: while hurricanes could be fewer as time goes on, the ones that do sweep in are likely to be more powerful, with higher winds and more devastating storm surges that will drive the high water much deeper inland. link

 USA wetlands

The land area that now makes up the United States originally contained almost 392 million acres of wetlands (221 million acres in the lower 48 states). Considerable changes in wetland distribution and abundance has taken place since the 1780s. In the conterminous United States, only an estimated 104 million acres of wetlands remained through the 1980s, representing a 53% loss from the original acreage total. If Alaska and Hawaii are counted, an estimated 274 million wetland acres remain. In the 1980s, wetlands constituted only 5% of the land surface in the lower 48 states, or 12% if Alaska and Hawaii are included. Alaska continues to have the vast majority of wetland acres with an estimated 170 million approximately 45% of that state’s total surface area. Among the lower 48 states, Florida, Louisiana, Minnesota, and Texas have the greatest wetland acreage. link     Link to learn more about wetlands in each state.

BP 2010 Gulf oil spill – effects on wetlands. As oil migrates into the wetlands, several possibilities for dealing with it exist. But not all of them are practicable in this situation, Controlled burns are perhaps the least-worst alternative among a handful of approaches. link

December 2013: Study says U.S. losing wetlands to storms, sea-level rise. Over a four-year span, the United States lost more than 360,000 acres of freshwater and saltwater wetlands to fierce storms, sea-level rise and booming development along the coasts, according to a newly released federal study. The disappearance of so much grass and forest marsh on the edge of waterways is a disturbing sign that government projects to restore wetlands are failing to keep pace as storms intensify, the sea level creeps up and development paves the way for rising coastal populations. link

August 2014: Southeast Louisiana is disappearing, quickly. In just 80 years, some 2,000 square miles of its coastal landscape have turned to open water, wiping places off maps, bringing the Gulf of Mexico to the back door of New Orleans and posing a lethal threat to an energy and shipping corridor vital to the nation’s economy. At the current rates that the sea is rising and land is sinking, National Oceanic and Atmospheric Administration scientists say by 2100 the Gulf of Mexico could rise as much as 4.3 feet across the landscape,  which has an average elevation of about 3 feet. If that happens, everything outside the protective levees – most of Southeast Louisiana – would be underwater. link

 Around the world

Global losses of wetlands have been exceptional during the last two centuries. Estimates of wetland loss exceed 50% for the conterminous United States and for Europe. More extreme cases include losses of 80% of Pacific Coast estuarine wetlands in Canada; 88% of the Cauca River system in Colombia; and 90% (or more) of wetland areas in New Zealand and in the states of Ohio and California. The remaining wetlands are increasingly valued for their ecological services, that is, benefits wetlands provide to people. In Africa, for example, where shortages of protein continue to cause malnutrition, the area of wetland in a watershed is a strong predictor of fish harvests. Perhaps the most important, yet least appreciated, value of wetlands is their very wetness, water has been identified as one of the critical limiting resources for human civilization. link

August 2018: The Amazonian wetlands. According to a new study, the Amazon region’s wetlands are inhabited by 3,615 tree species, three times more than previously estimated, making these the world’s most diverse wetland forests in terms of tree species richness. link

July 2018: Britain’s coastal wetlands will vanish under rising sea levels. Marshlands stretching across the southeast coast of England may be overwhelmed by rising sea levels in the coming decades, scientists have warned. They found that as seawater encroaches further into these coastal wetlands, marshes in southeast England could begin to disappear from 2040. Salt marshes, also called coastal wetlands, act as a buffer against coastal storms to protect the mainland and a filter for pollutants to decontaminate fresh water. link

April 2017: Rural Kenyans protect wetlands to curb water scarcity. Kenya’s wetlands have suffered in the drought, putting at risk communities who depend on them for fishing or irrigation, and who rely on them to act as a buffer from floods and drought. Wetlands such as lakes and floodplains act as natural safeguards against disasters, by absorbing excess rainfall during floods, with the stored water then available in times of drought. link

Suggested sources

Wetlands International (A global not-for-profit organisation dedicated to the conservation and restoration of wetlands.)
Society of Wetland Scientists