Tune in to WYPR 88.1 FM in Baltimore at 9:35 a.m. tomorrow morning (Wednesday, May 14) to hear my next "Environment in Focus" radio show. This segment will be called "Wetlands and Global Warming."

If you aren't going to be listening to your radio at that time, you can listen anytime by clicking here.

The program will talk about the research of two scientists who are conducting cutting-edge studies on wetlands on opposite sides of the Chesapeake Bay: Brian Needelman of the University of Maryland, who's working at the Blackwater Wildlife Refuge on the Eastern Shore; and Carl Mitchell of the Smithsonian Environmental Research Center, whose studying Kirkpatrick Marsh south of Annapolis.

Needelman (below) proposes that building wetlands would be a great tool in fighting global warming. Marsh grass absorbs carbon dioxide as it grows.  So if polluters (like power companies) were required to build large new wetlands, that might "offset" some of the damage done by their pollution.

 Brian Needelman at the Blackwater National Wildlife Refuge on Maryland's Eastern Shore.  (Sun photo by Doug Kapustin)

But Mitchell (below) raises warnings about the possibility that building vast new marshes could worsen mercury contamination in fish.  That may sound odd, because wetlands are often seen as purely good in an ecological sense.  But Mitchell and other researchers are documenting how marshes transform air pollution from coal-fired power plants into methylmercury, which accumulates in fish and can cause brain damage in people.

 Carl Mitchell in Kirkpatrick Marsh, owned by the Smithsonian Environmental Research Center, south of Annapolis.