Wednesday, June 6, 2012

Virginia's dying marshes and climate change denial

Daniel Nasaw in BBC News Magazine: Dying wetland trees along Virginia's coastline are evidence that rising sea levels threaten nature and humans, scientists say - and show the limits of political action amid climate change scepticism. In the salt marshes along the banks of the York River in the US state of Virginia, pine and cedar trees and bushes of holly and wax myrtle occupy small islands, known as hummocks.

But as the salty estuary waters have risen in recent years, they have drowned the trees on the hummocks' lower edges. If - when - the sea level rises further, it will inundate and drown the remaining trees and shrubs, and eventually sink the entire marsh. That threatens the entire surrounding ecosystem, because fish, oysters and crabs depend on the marsh grass for food.

"These are just the early warning signs of what's coming," says avian ecologist Bryan Watts, stepping carefully among the fallen pines. The sea level in the Chesapeake Bay area and in south-eastern Virginia is predicted to rise by as much as 5.2ft (1.6m) by the end of the century.

Ancient geologic forces are causing the land literally to sink, while the amount of water in the oceans is increasing because of global warming, scientists say. As a result, the low-lying coastal areas - and the towns in it - are at tremendous risk of flooding.

...But in Virginia's state capital Richmond, as in Washington, many politicians remain sceptical about the extent to which humans are responsible for global warming. They fear measures needed to curb climate change would hurt the economy, threaten private property, and harm commercial and industrial interests....

This is a map of the York River Watershed and includes the Mattaponi and Pamunkey rivers. Karl Musser, created it based on USGS data. Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.5 Generic license

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