This Week's Take:

Chesapeake Bay: A legacy in peril

Courtesy photo
John Cleveland lives in Grasonville on the Eastern Shore and runs the nonprofit Global Warming Action Alliance.

Published November 24, 2007
The Capital

The world is warming faster than anyone expected.

The climate history stored in the Earth's rocks, tree rings, ocean sediments and ice have shown that climate changes do occur abruptly, sometimes within a decade.

Since mankind has unequivocally caused this warming and now controls the climate, perhaps we should prepare for the climate future we've created.

According to Dr. Marco Tedesco of the University of Maryland, Baltimore County and NASA, Antarctic ice is melting at higher altitudes and farther inland than previously thought. From 1987 to 2006, the continent's largest ice shelf, the Ross Ice Shelf, has degraded significantly: 900 kilometers from the coast and 2 kilometers in altitude.

Ice shelves slow the flow of glaciers, so as the Ross Ice Shelf destabilizes, more ice will flow into the sea, raising sea levels.

At the other end of the world, reports from the latest Greenland expedition, led by Grasonville's Dr. Robert Corell, director of the Heinz Center for Global Change, tell of an ice sheet riddled with moulins (holes in the ice into which the melt water flows) 10 to 15 meters wide. 'It looks like a piece of Swiss cheese.'

Winter temperatures have risen more than 8 degrees Fahrenheit since 1994 in Greenland.

The deteriorating condition of the ice led Dr. Konrad Steffen from the University of Colorado at Boulder, to hope his estimate of a 3 foot rise in sea levels by 2100 does not happen. But 7 1/2 feet may be more realistic.

Dr. Tim Lenton, of Britain's University of East Anglia, surveyed climate and glacial experts around the world. The consensus is that the 'tipping point' may occur much earlier than previously predicted. The breakup could happen in as little as 300 years, raising sea levels 23 feet.

This recent information renders grossly inadequate the Intergovernmental Panel on Climate Change's Fourth Assessment projections for sea level rise due to ice melt.

But what does this bode for the Eastern Shore?

The Chesapeake Bay now floods 580 acres of land every year. Sea levels will continue to rise due to thermal expansion, adding an average of 12 inches by 2100.

Land subsidence will account for an equal amount, and considering Greenland and Antarctica, your toddler's toddler may very well see a normal Chesapeake Bay water level 3 feet or more above present day.

The National Oceanic and Atmospheric Administration tells us that Maryland is the third most vulnerable area in the country to sea level rise and storm surge. A Category 1 hurricane storm surge could raise water levels 10 feet.

The Maryland Department of the Environment reports that the surge would inundate 13.4 percent of Maryland structures, representing a loss of $1.2 trillion. Only 3 percent have flood insurance.

We must remember that scientists and policy makers are dealing with rapidly changing data from a rapidly warming planet — Carbon dioxide levels have increased 35 percent beyond projections since 2000!

Temperatures will continue to rise and according to a report by the Northeast Climate Impacts Assessment Team, Maryland may, by 2100, have the climate of Key West.

This tropical weather will bring with it invasive species carrying dengue fever and malaria and will probably cripple Chesapeake Bay ecology, fisheries and recreational activities. Crops will fail due to extended droughts, and tropical cyclone activity will increase.

These projections will change for the worse if greenhouse gases continue to rise unabated, unless we change the way we live.

Changing the way we live means reducing and eliminating the use of fossil fuels. Now.

Mankind cannot afford to wait for our leaders to act.

Dr. James Hansen, NASA's top climate scientist, tells us that we have less than eight years.

The Earth has already warmed 1.7 degrees Fahrenheit, and there is another degree in the pipeline; meaning we are committed to a 2 to 3 degree temperature rise, which in climate terms is staggering.

The problem is global but the solutions are local. The greatest and easiest reductions in fossil fuel use come from efficiency and conservation. That's something we can all do to change the climate future for the better.

(Revised Nov 2007)