I pointed out in a Dredd Blog series that there is no denying the threat of nuclear war as a means of human extinction (Civilization Is Now On Suicide Watch - 2).
It was also pointed out in that post that those who inhabit the home of climate change deniers, the GOP, agree with that assessment of nuclear war (ibid).
Today, I want to argue the case that sea level rise (SLR) is the greatest threat to civilization at this time, even though it is not the greatest threat to human species extinction at this time (Civilization ≠ human species).
The graphic and link under the graphic captures the concept, because it shows a city abandoned because SLR has reached a level causing it to have to be abandoned, and the people that once thrived there have had to move inland.
They are not yet extinct.
The sea being an equal opportunity sub-merger will have done the same thing to thousands of cities around the globe, destroying civilization as we know it (see e.g. Will This Float Your Boat - 10, Will This Float Your Boat - 9, The Question Is: How Much Acceleration Is Involved In SLR? - 4).
Very Little More Will Cause This To Happen
To illustrate this point, how big a deal is 3 ft / 1 m. of SLR, let's calculate the percentage
| Image may be NSFW. Clik here to view.  |
| Fig. 1USGS (click to enlarge) |
At those hot spots (see Fig. 1), let's do a conversion to percentage (3 ft. / 263.5 ft. = 0.011385199) = 1.14%.
How little it will take can also easily be seen by a statement from a scientist who is studying those locations closely and regularly:
"One of them, Totten glacier, holds the equivalent of seven metres of global sea level."(Dr. Rignot East Antarctica glaciers, cf. Totten Glacier Melting). The percentage of that one glacier which needs to melt to cause 3 ft. / 1 m. of SLR is (1÷7 = 0.142857143) ~14%.
When fourteen percent of just one glacier, the Totten Glacier, melts or flows to the sea, or when 1.14% of all the world's ice melts or flows to the sea, civilization as we know it goes lights out, and a different civilization emerges:
The harms associated with climate change are serious and well recognized. The Government’s own objective assessment of the relevant science and a strong consensus among qualified experts indicate that global warming threatens, inter alia, a precipitate rise in sea levels, severe and irreversible changes to natural ecosystems, a significant reduction in winter snowpack with direct and important economic consequences, and increases in the spread of disease and the ferocity of weather events. [quoting U.S. Supreme Court](Will This Float Your Boat - 10). If you are having a difficult time wrapping your mind around this, look at the depiction of New York harbor at the top of the post, and ask yourself how all those container ships can come into that place to load or unload their cargo.
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"By volume, more than 95 percent of U.S. international trade moves through the nation's ports and harbors, with about 50 percent of these goods being hazardous materials." [quoting NOAA 'Ports']
The roads are closed, the power is off, everyone is gone inland to camps, and it is that way at every port.
Food, clothing, oil, coal, and other goods cannot go back and forth in the manner of Current Civilization's established international intercourse.
This is a game changer we are talking about, and it could happen far more quickly than you have yet heard.
If "the dam breaks" at Greenland or Antarctica, lights-out will happen before governments and their citizens can prepare for what is to come quickly.
Nations will become isolated, and will have to rely on themselves more than they have (Will This Float Your Boat - 9).
HBO Vice: Our Rising Oceans with Dr. Eric Rignot:
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2:43 - One meter [SLR] would be a global catastrophic event, 3 meters would remap the world as we know it?
2:50 - Yes, absolutely.