Drowning the National Heritage: Climate Change and U.S. Coastal Biodiversity

Say the words “extinction crisis,” and what most likely comes to mind first is a tropical forest in flames – an apt image when deforestation is the main force behind a species extinction rate unmatched in 65 million years.

But Americans concerned about saving tropical forests’ vast biological wealth must not lose sight of losses much closer to home, including the degradation of U.S. seashores, coral reefs, barrier islands, estuaries, and coastal wetlands.

These coastal habitats are home to teeming communities of plant and animal species, including our own. Some of this diversity is far from secure:

• 80 species that are at risk of extinction can live only on the strip of coastline that lies within 10 feet of sea level;



• beach-front development is already fragmenting coastal habitats, and rising population, temperature, and sea levels could compound these losses;



• the number of Americans living on coastal areas will probably reach 127 million by 2010, a 60-percent increase over a half-century of migration;



• Global warming could raise sea levels from two to five feet over the next century, in many casts outpacing particular ecosystems’ landward march.

Pollution, sedimentation, land-filling, residential and commercial construction, and other by-products of growing human populations are putting severe stresses on wetlands, coral reefs, mangroves, estuaries, and other coastal ecosystems. Add to these yet another set of threats associated with global warming, and the prospects for some of the world’s richest and most productive ecosystems grow dim.

What survival odds do species already in trouble have if their habitat keeps shrinking, squeezed on one side by a growing human presence and on the other by a rising sea?

What’s left of our natural heritage can’t be saved unless we awaken to the choices and trade-offs required.

Drowning the National Heritage examines the status of coastal biodiversity and the potential impacts of climate change: increased erosion, flooding, and salt-water intrusion into groundwater, rivers, bays, and estuaries as well as receding coastlines and altered coastal current and upwelling patterns.

The authors evaluate various policy responses and recommend specific policy changes to protect the biological wealth of these vital ecosystems:

• Incorporating the protection of coastal ecosystems as a fundamental goal in federal and state policies;



• Eliminating federal and state subsidies that promote coastal development and coastal defense;



• Making wide use of such regulatory measures as coastal zoning and setbacks;



• Putting property owners on notice that sea level will rise and that large area of what is now dry land wil eventually have to be abandoned;



• Minimizing human stresses other than sea level rise on coastal ecosystems;



• Identifying appropriate policies for key coastal ecosystems.

The authors also suggest that nongovernmental organization that buy land for conservation purposes whould begin experimenting with easement and leasing options that would allow them to protect wetlands and other coastal ecosystems as the sea rises.