What ‘unstoppable’ Antarctic ice melt means for Western cities

Krista Langlois

Save for a freak May snowstorm, the other day started off normally. I woke up, made a giant mug of coffee and walked to work. But May 12 was no ordinary Monday.  “Today,” said Eric Rignot, a glaciologist at the University of California, Irvine, “we present observational evidence that a large sector of the West Antarctic Ice Sheet has gone into irreversible retreat. It has passed the point of no return.”

Language that strong isn’t often tossed about at NASA news conferences, and the world took notice. Climate change advocate Protect Our Winters called it “the day that all climate scientists feared.” Mother Jones coined it a “holy shit moment for global warming.” The well-known Canadian environmental writer Chris Turner tweeted that it’s “the most important news story you’ll see this week, by a wide margin.”

So what’s all the fuss about – and why should you care? In the most basic terms, two separate scientific studies, using two different models and released by two reputable scientific journals, both came to the same conclusion: Glaciers on the West Antarctic Ice Sheet are melting more rapidly than expected and have begun a domino effect that’s virtually unstoppable, even if we cut off greenhouse gas emissions today. Over the course of hundreds of years, the melting glaciers will boost ocean levels by 4 to 16 feet, changing the geography of the world as we know it.

Previous models, of course, have also predicted sea level rise, and West Coast cities have begun preparing by relocating threatened structures, moving drinking water supplies and modifying construction permits. But no previous study has been this conclusive or concrete in its modeling, nor taken into account the degree of Antarctic melt now considered inevitable. The Intergovernmental Panel on Climate Change (IPCC) warned earlier this year that global sea level could rise between four inches and three feet by 2100, but the new findings make such predictions seem almost quaint. Penn State University geoscientist Sridhar Anandakrishnan told NBC News that future IPCC estimates “will almost certainly be revised” upwards as a result of the new studies.

What could rising seas actually look like for the West Coast? Andrew David Thaler, a deep-sea ecologist, posed that question to his Twitter followers last fall, and the response was tremendous: Requests poured in from around the world asking Thaler to virtually inundate their hometowns under the hashtag #DrownYourTown. #DrownYourTown has now been tweeted millions of times, and Thaler has perfected a real-time, interactive GIS modeling technique that allows him – or anyone with basic technology skills – to visualize what coastal cities might look like with varying amounts of sea level rise.

Thaler warns that the images aren’t exact and shouldn’t be used to make real estate decisions. But with once-theoretical sea level rises now a looming reality, these images make the future of the West Coast graspable. Here are a few we found particularly unsettling. (Click images to enlarge.)

If the West Antarctic Ice Sheet completely melted into the Amundsen Sea – as the new studies from NASA, UC Irvine and the University of Washington predict will eventually happen – the resulting 16 feet of sea level rise would look like this:

Marin City
Marin City, California 

 

Here’s downtown San Francisco with 22 feet, the rise that would occur if the entire Greenland Ice Sheet melted (a scenario not part of the new studies):

San Francisco 1

 

San Francisco 2

And, just for kicks, a couple of cities with 32 feet sea rise

Vancouver, British Columbia
Vancouver, British Columbia
San Diego
San Diego, California 

 

Yeah, yeah, you’re saying. My great-grandkids won’t even be alive for that. How about something more immediate?

The new studies don’t make predictions for specific years, so the best we can do for the end of this century – the year 2100 – is the IPCC’s latest estimate of about 4 feet sea level rise. Keep in mind that figure may be conservative, as scientists now say the IPCC estimates will likely increase in light of to this new information. Either way, here are a couple non-Western spots with about 3 feet sea level rise:

Key West, Florida
Key West, Florida

 

 

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