Washington Is Sinking, and It’s Only Going to Get Worse

Berkeley CA

Description

Washington Is Sinking, and It’s Only Going to Get Worse Government climate scientist Virginia Burkett talks about what we can expect. WRITTEN BY PAUL O'DONNELL | PUBLISHED ON MARCH 7, 2017 TWEET SHARE Photograph by Jeff Elkins Skepticism has become Washington’s official policy on climate change, but even nonbelievers can’t miss some long-advertised effects of global warming that have begun to show up on our doorstep: “nuisance flooding” in DC’s Palisades and Annapolis, higher heat indexes, and sinking islands in the Chesapeake Bay. We invited Virginia Burkett, who oversees climate science at the US Geological Survey—the feds’ 139-year-old land-use agency—to talk about what more we can expect. Can you point to any local phenomenon as an example of climate change happening right in front of us? Flooding is probably the most obvious. Some places are flooding nearly five times more often today than a half century ago, and on the waterfront in the District, especially, what’s known as nuisance flooding is a growing problem. Several Metro stations already flood regularly. With more heavy rainfall events, that’s going to get worse. So rain is the biggest problem? It’s a combination of heavy rainfall events and human development—all the asphalt and other building we do, rerouting streams. The land around the Chesapeake and near DC is also sinking. Wait—sinking? It’s called subsidence, caused by natural changes in the earth’s surface as the ice sheets melt and by groundwater withdrawal—pumping water out of wells. The rate of subsidence ranges around DC from about 1.5 to 2.5 millimeters per year. It’s higher in the bay. In the lower bay region, it’s been half a centimeter a year since the 1940s. Half of that is from subsidence. To a layperson, a couple of millimeters doesn’t sound like much. It’s not much, but over 10 or 50 years, it adds up. You can see it in the way some islands in the Chesapeake have been inundated. There’s been a dramatic loss of wetlands in the Blackwater National Wildlife Refuge on the Eastern Shore—more than 5,000 acres are gone since the 1940s due to subsidence and sea-level rise. Water levels in the Potomac and Anacostia rivers have risen roughly 11 inches in the past century. In the climate maps that the US Global Change Research Program puts out, Virginia is assigned to the southeast region and DC and Maryland are in the northeast. Are there appreciable differences in how the two halves of Washington will experience climate change?