On the eve of the big Copenhagen summit meeting, as world leaders -- including, briefly, President Obama -- work from Dec. 7 to Dec. 18 to hammer out a new agreement for combating climate change, it's worth noting a new report by the International Union for the Conservation of Nature, or IUCN.

The study by the IUCN --the world’s oldest and largest global environmental network, with almost 11,000 volunteer scientists in more than 160 countries -- found that mangroves and salt marshes have a greater capacity for trapping carbon than better-known land carbon sinks.

"The simple implication of this is that the longterm sequestration of carbon by one square kilometer of mangrove area is equivalent to that occurring in fifty square kilometers of tropical forest," the IUCN report says.

Those coastal wetlands also disappearing a lot faster than terrestial ecosystems, according to the paper, titled "The Management of Natural Coastal Carbon Sinks."

“The current loss of two-thirds of seagrass meadows and 50 percent of mangrove forests due to human activities has severely threatened their carbon storage capacity and is comparable to that of the annual decline in the Amazon forests,” says Dan Laffoley, vice-chair of the IUCN’s World Commission on Protected Areas and the report's lead author. “Urgent international action is needed to ensure that coastal marine ecosystems are fully recognized as critical carbon sinks and properly managed and protected.”

And what happens when those wetlands disappear? "Drainage projects, in combination with the effects of periodic droughts, can lead to large-scale fires, which release enormous amounts of carbon dioxide into the atmosphere, and thus contribute to global warming," according to a new study written up in Science Daily.

The study by German researchers found that in 2006, peatland fires in ditched and drained wetlands in Indonesia released up to about 900 million metric tons of CO2, which is more than far more industrial Germany released that year.