There was recently a Grist article about Andrew Thaler’s easy technique to visualize sea level rise.  His maps show the near complete loss of some cities with the worst-case 80m sea level rise.  This is roughly the level at which the Greenland and Antarctic ice sheets have completely melted, along with the world’s glaciers. I’m not a climate scientist, but WUnderground has a good description of the current (3.1mm/yr) and predicted future sea level rise.  They describe the IPCC’s prediction for “most likely” rises of 0.8 to 2 m by 2100.  I include this to say the 80m level is a long, long time from now and only if things go terribly wrong.  But for entertainment purposes, here is Seattle at 80m sea rise, with more after the jump:

Boeing Field no longer looks like the best use of land.

Here’s the logical location of our new downtown, on Cap Hill Island:

And the beautiful beach front property at Kerry Park:

30 Replies to “Seattle with an 80m Sea Level Rise”

  1. Let me see if I got the subtext right. If I don’t give up my car and move downtown and exclusively take public transit, the global warming I am currently contributing to will eventually murder millions of people?

    BTW, anyone else notice the sea level rise fills in exactly those areas carved out by previous glacial periods?

    1. Lots of things contribute to carbon emissions and climate change. It’s a collective problem that requires collective action. The movement of any one person “to downtown” is mostly meaningless — instead, the way we’ve built and changed our cities in the last 90 years or so, primarily and sometimes exclusively around automotive access, must be reversed.

      1. There’s a difference between an event taking a reallly looonnngggg time (10,000 years+) and an event that takes 150-200 years to happen.

    2. Yikes – better pick the right part of downtown.

      I hope the folks running the Underground Tour invest in some submarines. I don’t think this is going to be a flash flood so people will get out of town fast enough.

      (To be nitpicky – not “murder” – that’s the premeditated killing of one human by another. They’d have to show intent.)

      Any parts of this underwater that would have been above the line prior to the regrade?

    3. Yes, Sam, now you’re getting something. And lower your electricity use by 90%.

      Obviously in any scenario that makes Capitol Hill an island, the whole notion of jobs and offices and commuting would be radically changed. People would be busy installing rooftop gardens and ensuring adequate housing, not pushing papers in offices. And if they can’t run the lighting and HVAC in the highrise and midrise buildings, they may not be usable anyway.

  2. What do you mean by “terribly wrong”? How much CO2 do we have to pump into the atmosphere to get to this level?

    1. As I said, I’m not a climate scientist. My understanding is that there are quite a few positive feedback loops involved that could make warming accelerate. One simple example is snow – melt that shiny white stuff and expose dark rock, and there’s less sunlight reflected to space. Another is methane trapped under our oceans, which is a strong greenhouse gas and which will be released as temperatures increase (this has already started to happen “at a rate more than twice what scientific models had previously anticipated”) – I’d guess this is a much tougher problem to predict than the snow melt issue, as we don’t really know how much methane is under the oceans or how much will be released.

      I’ve searched the Internet a bit for predictions of past 100 years, and can’t find anyone credible to make any prediction.

  3. Clearly, if we have to push the slider up so high to put Cap Hill on an island, sea level rise in Seattle is not the biggest problem we’ll see here from climate change. Flatter coastal cities have it much worse. But disruptions to the economy and food production are a big deal for every city.

    1. Several states on the East coast would be completely submerged by this point. I can’t imagine any part of Florida being above sea level at that point for one…

      1. Precisely. As ever increasing storm surge related events drain resources away from the west coast, we are left to our own to provide for anything new (rail, bus, roads). We’re seeing trends in that direction today after Katrina and Sandy, and that’s with less than a foot of sea-level rise since 1900. Most models point to 6 feet rise by 2100.
        How many times a year can you flush the NY Subways with sea water before they crumble?

      2. Florida goes first, and actually in all reputable predictions, even the best-case predictions, we lose everything south of Orlando.

        It’s a waste to build *anything* in Miami.

      3. Oh — and unlike some low-lying coastal cities which are built on rock, you can’t save Miami even with seawalls. The ground is porous and the water will come right up from underneath — which is *already happening* in some people’s yards. (Florida is basically a giant river delta.)

  4. Yes well, that NY subway thing is a joke! Why don’t they raise the land around the entrances by 3 to 5 feet, to stop water from entering.
    And, at 80 feet, Manhattan will be almost totally submerged.

  5. At 560 ft on Kent East Hill, I’d be living in a beach town!

    So, let ‘er rip, global warming!

      1. The return of the mosquito fleet….

        What we don’t see here are the successive sea walls we are likely to have built to attempt to mitigate the coming waters before they became too high to overcome with mere walls.

        It depends on how quickly the water level ascends though…

  6. Looks like this will help cut KCM bus service by the requisite 17% or so. But it likely would prevent PT and CT from expanding.

  7. Very nice geoimaging, Matt. But you should have wiped out the snow on Mount Baker….. If there are no glaciers in Antarctica, there sure as hell won’t be any on Mount Baker.

    1. That’s, um, the attempt to reverse global warming we try out in 2250 by painting all of our mountains white. Sadly the fumes from the paint are found to emit a greenhouse gas in their manufacturing process…

  8. A simpler online version of this using Google Maps is still available at:

    This version has preset flood heights and makes some odd jumps—every meter from 1 to 7, then it skips to 9 meters, 13 meters, then every 10 meters from 20 to 60—but still will let you quickly see how things could change sooner than we’d reach the 80-meter level.

    (The default setting for the site is the United Kingdom at 7 meters; here’s a direct link to the Seattle area, set at 0 meters:,-122.3261&zoom=10&m=0 )

    1. Excellent. It seems like SoDo is in trouble right from the first meter. By 13 meters there are surprising areas that are flooded – coming in at Marysville and extending past Duvall. Both Redmond and Renton are trouble. At first I thought we could just build the locks higher to protect Redmond, but then we’re stuck actively pumping the below-sea-level lake out continuously. Even at 13 meters most of downtown Seattle hangs on.

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