Peat Bogs Help to Mitigate Climate Change

article image
Photo courtesy CORBIS
Peat bogs are diverse ecosystems that form solely from surface water and precipitation.

One step forward for wetlands, but two steps back for peat bogs? For a while there, it appeared that wetland conservation was on the upswing, experiencing an 80 percent reduction in annual loss of acreage over the last decade. But last winter, the Supreme Court decided to limit the scope of the Clean Water Act and exclude wetlands that are not attached to another body of water—a ruling that may have a devastating effect on those peat bogs that accumulate water exclusively by precipitation. 

Wetlands act as buffers between land and liquid, working like sponges to moderate flood control, water quality and coastal erosion. The peat bogs that rim the Northern hemisphere may also play a crucial role in mitigating climate change. “There are lots of intersections between global warming and wetlands,” says Dan Becker, director of the Sierra Club’s Global Warming and Energy Program. Fluctuating sea and lake levels could have devastating effects on the wetlands, he says, which could result in dire global consequences since wetlands are also storage tanks for carbon. 

Peat bogs contain sphagnum moss, sometimes many feet thick. In the oxygen-poor environment of a bog, the moss remains stable. But when phenol oxidase goes to work breaking peat down into humus, between 20 and 75 percent of the moss’s carbon mass is released as carbon dioxide. New Scientist magazine reports that the 455 billion tons of carbon buried in peat bogs worldwide would release the equivalent of 70 years of industrial emissions. Scientists disagree on whether changing water levels or pH stimulate the enzyme, but some worry that drying wetlands would belch greenhouse gases and cause temperatures to climb even higher. 

Amid increasing reports that global warming is real and occurring faster than predicted, drying out wetlands seems like a step in the wrong direction.