Scientists to discuss climate risk posed by wetlands destruction

Yahoo News 20 Jul 08;

Moves around the world to drain marshes and other wetlands to make space for farming could be hastening climate change, scientists gathering in Brazil from Monday will be hearing.

Around 700 researchers from around the world are to descend on the central western town of Cuiaba for a four-day conference to discuss ways to preserve wetlands, the UN University, a grouping of scholars, said in a statement.

They are concerned that evaporation from warmer global temperatures and man's destruction of wetlands are releasing massive amounts of carbon into the atmosphere, which could be increasing greenhouse gases.

Wetlands such as marshes, swamps, mangroves, peat bogs and river floodplains cover six percent of the Earth's land surface, and store up to 20 percent of terrestrial carbon in the form of slowly decaying organic matter, the statement said.

They are estimated to contain 771 billion tons of greenhouses gases -- carbon dioxide and methane -- an amount comparable to the carbon content already in the atmosphere.

According to the UN University, 60 percent of wetlands around the world have been destroyed in the past century, mainly to provide drainage for farming.

"Too often in the past, people have unwittingly considered wetlands to be problems in need of a solution. Yet wetlands are essential to the planet's health," said UN Under Secretary-General Konrad Osterwalder, who is also rector of the UN University.

A German expert, professor Wolfgang Junk of the Max Planck Institute for Evolutionary Biology, added: "Wetlands act as sponges and their role as sources, reservoirs and regulators of water is largely underappreciated by many farmers and others who rely on steady water supplies."

The conference, co-organized with Brazil's Federal University of Mato Grosso in Cuiaba, will be looking at ways to protect and better manage wetlands, some of which extend over national borders.

Cuiaba itself is on the edge of the Pantanal, a remote and therefore relatively untouched wetland straddling Brazil, Bolivia and Paraguay.

The UN University is a community of researchers studying pressing global problems set up by the UN General Assembly. Its headquarters is in Japan.

Wetlands Could Unleash "Carbon Bomb" - Scientists
Deborah Zabarenko, PlanetArk 21 Jul 08;

WASHINGTON - The world's wetlands, threatened by development, dehydration and climate change, could release a planet-warming "carbon bomb" if they are destroyed, ecological scientists said on Sunday.

Wetlands contain 771 billion tonnes of greenhouse gases, one-fifth of all the carbon on Earth and about the same amount of carbon as is now in the atmosphere, the scientists said before an international conference linking wetlands and global warming.

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 by telephone from from Cuiaba, Brazil, site of the conference. "It's a very tricky situation."

Some 700 scientists from 28 nations are meeting this week at the INTECOL International Wetlands Conference at the edge of Brazil's vast Pantanal wetland to look for ways to protect these endangered areas.

Wetlands are not just swamps: they also include marshes, peat bogs, river deltas, mangroves, tundra, lagoons and river flood plains.

Together they account for 6 percent of Earth's land surface and store 20 percent of its carbon. They also produce 25 percent of the world's food, purify water, recharge aquifers and act as buffers against violent coastal storms.

Historically, wetlands have been regarded as an impediment to civilization. About 60 percent of wetlands worldwide have been destroyed in the past century, mostly due to draining for agriculture. Pollution, dams, canals, groundwater pumping, urban development and peat extraction add to the destruction.

IMAGE PROBLEM

"Too often in the past, people have unwittingly considered wetlands to be problems in need of a solution, yet wetlands are essential to the planet's health," said Konrad Osterwalder, UN Under Secretary-General and rector of United Nations University, one of the hosts of the meeting.

So far, the impacts of climate change are minor compared to human depredations, the scientists said in a statement. As is the case with other environmental problems, it is far easier and cheaper to maintain wetlands than try to rebuild them later.

As the globe warms, water from wetlands is likely to evaporate, rising sea levels could change wetlands' salinity or completely inundate them.

Even so, wetland rehabilitation is a viable alternative to artificial flood control for coping with the larger, more frequent floods and severe storms forecast for a warmer world.

Northern wetlands, where permanently frozen soil locks up billions of tonnes of carbon, are at risk from climate change because warming is forecast to be more extreme at high latitudes, said Eugene Turner of Louisiana State University, a participant in the conference.

The melting of wetland permafrost in the Arctic and the resulting release of carbon into the atmosphere may be "unstoppable" in the next 20 years, but wetlands closer to the equator, like those in Louisiana, can be restored, he said.

Teixeira admitted wetlands have an image problem with the public, which is generally well-disposed to saving the rainforest but not the swamp.

"People don't have a good impression about wetlands, because they don't know about the environmental service that wetlands provide to us," he said. (Editing by Alan Elsner)

Warming world 'drying wetlands'
BBC News 22 Jul 08;

More than 700 scientists are attending a major conference to draw up an action plan to protect the world's wetlands.

Organisers say a better understanding of how to manage the vital ecosystems is urgently needed.

Rising temperatures are not only accelerating evaporation rates, but also reducing rainfall levels and the volume of meltwater from glaciers.

Although only covering 6% of the Earth's land surface, they store up to an estimated 20% of terrestrial carbon.

Co-organised by the UN University and Brazil's Universidade Federal de Mato Grosso, the five-day Intecol International Wetlands Conference in Cuiaba, Brazil, will examine the links between wetlands and climate change.

"Humanity in many parts of the world needs a wake-up call to fully appreciate the vital environmental, social and economic services wetlands provide," said conference co-chairman Paulo Teixeira.

These included absorbing and holding carbon, regulating water levels and supporting biodiversity, he added.

Konrad Osterwalder, rector of the UN University, said that people in the past had viewed the habitats as a problem, which led to many being drained.

"Yet wetlands are essential to the planet's health," he explained. "With hindsight, the problems in reality have turned out to be the draining of wetlands and other 'solutions' we humans devised."

Under pressure

Scientists warn that if the decline of the world's wetlands continued, it could result in vast amounts of carbon being released into the atmosphere and "compound the global warming problem significantly".

It is estimated that drained tropical swamp forests release 40 tonnes of carbon per hectare each year, while drained peat bogs emit between 2.5 to 10 tonnes.

Data shows that about 60% of wetlands have been destroyed in the past century, primarily as a result of drainage for agriculture.

"Lessening the stress on wetlands caused by pollution and other human assaults will improve their resilience and represents an important climate change adaption strategy," explained Wolfgang Junk from the Max Planck Institute for Evolutionary Biology, Germany.

"Wetlands act as sponges and their role as sources, reservoirs and regulators of water is largely underappreciated," Professor Junk added.

"They also cleanse water of organic pollutants, prevent downstream flood inundations, protect river banks and seashores from erosion, recycle nutrients and capture sediment."

The conference organisers said the ecosystems, many of which have biodiversity that rivals rainforests and coral reefs, were in need of complex long-term management plans.

They hope the scientific meeting, which ends on Friday, will highlight the range of measures needed, such as agreements that covered the entire catchment areas of the wetlands.