Warming Imperils Md. Species
Monday, March 19, 2007
The Baltimore oriole is the state bird of Maryland. The brown pelican is the state bird of Louisiana. But now, as climate change seems to be leaving its first footprints here, local scientists worry that the Washington area may be slowly trading one for the other.
About 1,000 brown pelican chicks hatched in Maryland last year. That was about 1,000 more of the birds, ungainly fish-eaters comfortable in the steamy Southeast, than there were in the state in 1985.
The oriole, by contrast, might be gone from here in a century. Researchers say that as Maryland's climate warms, the bird could shift its territory to the north, becoming, perhaps, the Philadelphia oriole.
As the global scientific community has settled on a consensus that the world is warming, local researchers have begun trying to understand the impact here. Already they've found enough to create serious concerns for the future -- about shifting bird migrations, increased "dead zones" in the Chesapeake Bay and bringing some beloved species to the edge of their tolerance for heat. Brook trout, the area's only native trout, could be disappearing from its last refuges in the woods of Frederick County, for instance.
This issue will take center stage in Washington tomorrow with a rally at the U.S. Capitol calling for reductions in greenhouse gases. Organizers, from the Episcopal Church to the National Wildlife Federation to the U.S. Public Interest Research Group, say Climate Crisis Action Day will be the largest rally about climate change ever in the capital.
It will be a political sign of what scientists already know: Washington is being changed by warming temperatures.
"We certainly know that we've been experiencing climate change impacts," said Bill Dennison, a vice president at the University of Maryland Center for Environmental Science. He added that even a seemingly slight warming trend can be significant in the interdependent world of nature.
"What's a degree? Well, think about if you ran a couple degrees' temperature," Dennison said. "We're already a couple degrees elevated. That's affecting our health."
The public's interest has been stoked recently by the Oscar-winning documentary "An Inconvenient Truth" and a U.N. report that says the temperature increase is "very likely" man-made, at least in part.
The causes of the warming, authorities believe, are the so-called greenhouse gases, which include emissions from cars and power plants burning fossil fuels. The gases accumulate in the atmosphere, creating a layer of insulation that holds in more heat.
Certainly, Washington has not missed out on the heat. Climate data show that the average annual temperature in the District has climbed about two degrees since the early 1960s. Weather data going back to the 1870s show that five of the 10 warmest years on record in the District have come since 1989.
Researchers have begun trying to learn how that trend is changing the surrounding ecosystems, from the wooded ridge of Catoctin Mountain to the weedy bottom of the bay. So far, the evidence is spotty, anecdotal and often inconclusive -- but it can still be arresting, when it shows eons-old processes threatened by change.