By David A. Fahrenthold
Washington Post Staff Writer
Thursday, September 27, 2007; B02

The governors of Virginia and Maryland urged a U.S. Senate panel yesterday to begin reducing national greenhouse-gas emissions during a hearing that described the creeping impact of climate change on the Chesapeake Bay.

Virginia's Timothy M. Kaine and Maryland's Martin O'Malley, both Democrats, told the Senate Environment and Public Works Committee that rising temperatures could bring problems such as larger "dead zones" and rising water levels around the bay.

Both governors said they had begun state-level programs aimed at staving off those changes. But, they said, the problem requires federal action, perhaps something like the "cap and trade" program used to reduce the pollutants that cause acid rain.

"The time to act is past," O'Malley said. "The time to catch up is now."

Yesterday's hearing was intended to highlight the bay, shared by Virginia and Maryland, as a local microcosm of the impact of climate change. The witnesses included a Methodist minister from Smith Island, Md., where three low-lying villages could eventually be swallowed by the water, and scientists who study the estuary.

Some of those researchers said the bay's other well-known problems, including polluted water and dwindled stocks of crabs and oysters, might only get worse as the region warms.

"Global climate change is not something in the Chesapeake Bay's future," said Donald F. Boesch, president of the University of Maryland Center for Environmental Science. "It's here today."

Witnesses said long-term studies show that the average water temperature in the bay has increased by nearly two degrees since the 1960s. Even a small-sounding shift can make the water too warm for some species, including eelgrass, a crucial underwater plant.

In the lower bay, vast eelgrass beds have served as nursery grounds where baby crabs and other creatures could hide from predators. But the plants cannot tolerate hot water, said William C. Baker, president of the nonprofit Chesapeake Bay Foundation.

"At 80 degrees, it simply dies," Baker said. "And we are seeing 80 degrees in the southern bay all too often."

Baker said another problem could be larger dead zones, areas where pollution-driven algae blooms consume the oxygen that fish and crabs need. Some bothersome algae species would be even more at home in a warmer bay, he said.

For people living around the bay, rising waters could present a major problem, several witnesses told the committee. The impact of increasing global sea levels, driven in part by climate change, are magnified here because land around the bay is slowly sinking. Together, Boesch said, those factors could result in a net rise of two feet or more over the next century.

The Rev. Richard Edmund said that could spell the end for the towns on Smith Island, where about 225 people live a few feet above high tide. Edmund, who oversees three churches on the island, said he was testifying so his grandchildren would know he had sought to warn others about climate change.

"I want them to know that I did what I could," Edmund said.

Both governors told the committee that their states had taken measures to attack the problem. Maryland has mandated reduced emissions from vehicles and power plants, and Virginia recently announced the goal of cutting emissions 30 percent by 2025.

Both pressed for more drastic moves from the federal government, which has been criticized for doing little while states have launched emissions-reduction programs.

Sen. John W. Warner (R-Va.), who was at the hearing yesterday, is working with Sen. Joseph I. Lieberman (I-Conn.) on a bill that would set a national cap on greenhouse-gas pollution and then let companies buy and sell allowances to emit.

One contrary note in the hearing came from Sen. James M. Inhofe (R-Okla.), who has said he thinks climate change is a hoax.

Inhofe said that the bay's rising waters were caused by natural processes and that the ecosystem would adapt.