Wednesday, October 21, 2015

The Extinction of Miami

Fig. 1 IPCC-5th Sea Level Rise
I mentioned yesterday that I had discovered a flaw ("bug") in the future projection of the Dredd Blog sea level change (SLC) software model.

It was doing what all SLC software models do, which is to underestimate sea level rise (SLR).

When I made some modifications (to use the trend line instead of the pattern emulation algorithm), the bug slipped in between two beers.

Anyway, while fixing that, I decided to settle on only two degrees of SLR in the model, instead of five or six.

The two degrees I settled on are the IPCC 5th Assessment (Fig. 1, Fig. 2) for the low side, and the Hansen et al. 2015 (A Paper From Hansen et al. Is Now Open For Discussion) for the high side (Fig. 3).
Fig. 2 IPCC projection

The difference between the two, in terms of how high should the next rain boots you buy be, is: buy hip-waders for the IPCC degree, but buy a boat for the Hansen degree.

Anyway, the extinction of venerable cities along the East Coast of the U.S.A. has been a theme recently, with lots of ("too many") graphs, so cutting it down to two well known varieties will be less tedious for all of us.

Fig. 3
And I can do something else more productive, like work up a post on "the domino theory" as one commenter recently seemed to suggest.

These two graphs (Fig. 1 and Fig. 2) are composed of historical data from the Key West tide gauge station.

Stations a bit closer to Miami have closed down, or do not have sufficient valid historical data to have made it into the Dredd Blog list of PSMSL stations.

Key West is one of the golden 23 tide gauge stations, so you can be sure that they have done a good job, along with the other 489, out of 1417 total PSMSL stations, which Dredd Blog uses for SLC data.

Note that the Hansen et al. theme is that global mean average SLR could reach ten feet (~3m) by 2050, while the IPCC says that global mean average SLR for 2100 will be closer to 4ft.

That is a classic "day and night" difference.

I would lay odds that Hansen and Co. will be closer.

Atlantis Miami

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