At the Blackwater National Wildlife Refuge on Maryland's Eastern Shore, sea-level rise threatens to drown the brackish marsh on which migrating shorebirds depend. In Northern California, the shrinking snowpack has reduced stream flows that sustain the delta smelt, a federally threatened fish species. Higher summer temperatures in northern Minnesota have depressed the birthrates of the area's once-populous moose, and just 20 inhabit the Agassiz National Wildlife Refuge that was designed in part to shelter them.
As climate change begins to transform the environment in the United States and overseas, policymakers and environmentalists are realizing that the old paradigm of setting aside tracts of land or sea to preserve species that might otherwise disappear is no longer sufficient. It was an idea that worked in 1872, when one of the reasons cited for establishing Yellowstone National Park was to help preserve the few remaining buffalo.
But as temperatures ...