Offering frequent news and analysis from the majestic Evergreen State and beyond, The Cascadia Advocate is the Northwest Progressive Institute's unconventional perspective on world, national, and local politics.

Wednesday, December 23, 2009

What does sea level rise mean for Washington?

Last week I wrote about the irony of what the climate crisis is going to do to Florida when sea levels rise, given that George W. Bush's brother played no small part in W himself becoming President. Given that the Copenhagen climate talks (or as some have dubbed them, the "Nopenhagen" talks) have ended with a pathetically watered-down set of agreements, let's take a look at what happens here in Washington, on the opposite corner of the continental United States.

See for yourself at this interactive sea-level map.

Many areas of our state will be impacted by that one-meter sea level rise that is present in even the most optimistic climate change forecasts. Here are the highlights for our state:

Columbia river basin: the sea reaches inland as far as Longview / Kelso, almost to where I-5 meets that north-flowing leg of the Columbia river. Expect storm surges and tidal forces to further ravage this roughly 50 mile stretch of river. Salt water intrusion is certain to mess up a whole lot of sensitive wetlands habitat along that stretch of river, too.

Long Beach / Ocean Park: expect serious beach erosion and property damage to tourist and resort areas here. Sections of Highway 101 and SR401, the only overland routes into this area, will have to be rebuilt or elevated to maintain access.

Hoquiem / Aberdeen: Parts of the waterfronts of these cities will be underwater, with larger areas of those cities becoming uninhabitable due to tides and storm surges. The river basin area around Chehalis will likewise become a saltwater marsh.

Port Angeles loses parts of its waterfront, and its coast guard air station will be underwater.

Sequim loses the Dungeness Spit, which currently shelters Dungeness Bay from the broader Strait of Juan de Fuca. The Old Town area of Sequim suffers substantial damage. The Spit can probably be raised, but building a seawall around Old Town is likely to be a much less feasible proposition.

Hood Canal: Ouch. Look for shoreline erosion and damage along the entire length of the canal. Flooding of low-lying areas will reach between 1 and 5 miles inland at Dabob Bay, Quilcene, and Belfair. The Skokomish Indian Reservation is particularly hard-hit, losing somewhere around one quarter to one third of its land.

The San Juan Islands: in terms of area, the San Juans get off relatively lightly because many of those islands have steep slopes leading down to the water. However, steep slopes indicate that the land is prone to vertical shearing as the ocean erodes it at the base, so we can expect a lot of landslides and cliff-face collapses. Sell your cliff-side vacation properties now before they fall into the sea.

Puget Sound: The sea crosses Interstate 5 between Fort Lewis and Lacey. At the Port of Tacoma, flooding extends inland up into Fife. The Port of Seattle Harbor Island area is similarly inundated, with flooding up the Duwamish river delta reaching as far as King County International Airport (a.k.a. Boeing Field).

Seattle metropolitan area: Seattle's waterfront is already well elevated in most places, although some low-lying areas such as Pioneer Square could see damage. The Ballard Locks will likely have to be re-enforced both to avoid property damage in Lake Union and Portage Bay, as well as to keep the sea out of Lake Washington. Or, we could fill in the Montlake Cut and restore Lake Washington's original outlet through the Duwamish River. That would work too.

Everett / Snohomish: Perhaps hardest hit of any heavily developed area in the state, this area stands to lose enormous amounts of land in the Snohomish River basin. The one-meter flood map of this area is particularly stark.

Skagit County: The areas around Skagit Bay and Padilla Bay--Stanwood, Milltown, LaConner, Whitney, and Edison--will be completely flooded out. The flood map here is no pretty picture either.

This is bad enough. One meter of sea level is no joking matter. But remember, this is presently the best case outcome. One meter is about what we're stuck with, so say the researchers, if we cut greenhouse gas emissions both quickly and aggressively. The best case, had Copenhagen produced a robust, worldwide binding agreement on emissions. Which it didn't.

Worst-case estimates are more like 10 meters--more than thirty feet--of sea level rise. And believe me, you don't want to see those maps. Seaside property in Vancouver, WA, anyone?


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