BLACKWATER NATIONAL WILDLIFE REFUGE, Md. -- What has gone missing here is almost as spectacular as the 8,000 acres of swampy wilderness that remain. And that makes it Chesapeake Bay's best place to watch climate change in action.
Visitors can see ospreys gliding overhead, egrets wading in the channels and Delmarva fox squirrels making their unhurried commutes between pine trees.
But then the road turns a corner, and Blackwater's marsh yields to a vast expanse of open water. This is what's missing: There used to be thousands more acres of wetland here, providing crucial habitat for creatures including blue crabs and blue herons. But, thanks in part to rising sea levels, it has drowned and become a large, salty lake. "If people want to see the effects" of Earth's increasing temperature, refuge biologist Roger Stone said, "it's happening here first."
But not just here. Around the world, scientists have found that climate change is altering natural ecosystems, making profound changes in the ways that animals live, migrate, eat and grow. Some species have benefited from the shift. Others have been left disastrously out of sync with their food supply. Two are known to have simply disappeared.
If warming continues as predicted, scientists say, 20 percent or more of the planet's plant and animal species could be at increased risk of extinction. But, as the shrinking habitat at Blackwater shows, the bad news isn't all in the out years: Some changes have already begun. "This is actually something we see from pole to pole, and from sea level to the highest mountains in the world," said Lara Hansen, chief climate change scientist at the World Wildlife Fund, a private research and advocacy group. "It is not something we're going to see in the future. It's something we see right now."
Adapting to the damaging effects of climate change, plants are gradually moving to where temperatures are cooler, rainfall is greater, f...