[... continued]
Unfortunately, humans are on a path to blow past 550 ppm and hit 800 to 1,000 ppm this century. The key point the anti-science crowd seems unaware of is that, as a
2009 NOAA-led study explained, impacts like sea level rise (and Dust-Bowlification) would be “largely irreversible for 1,000 years”:
Quote: …the climate change that is taking place because of increases in carbon dioxide concentration is largely irreversible for 1,000 years after emissions stop … Among illustrative irreversible impacts that should be expected if atmospheric carbon dioxide concentrations increase from current levels near 385 parts per million by volume (ppmv) to a peak of 450-600 ppmv over the coming century are irreversible dry-season rainfall reductions in several regions comparable to those of the ”dust bowl” era and inexorable sea level rise.
Lomborg’s idea of a “sensible” discussion may be one that ignores the science, but the fact is that the NOAA analysis gives the lie to the notion that it is a moral choice not to do everything humanly possible to prevent this tragedy, a lie to the notion that we can “adapt” to climate change — unless by “adapt” you mean “force the next 50 generations to endure endless misery because we were too damn greedy to give up
0.1% of our GDP each year.”
How fast can sea levels rise? That obviously depends on just how hot it gets. A
stunning 2011 paper in Science concluded that paleoclimate data suggest CO2 “may have at least twice the effect on global temperatures than currently projected by computer models.” It found that on our current emissions path, CO2 levels in the air in 2100 will hit levels last seen when the Earth was 29°F (16°C) hotter — and remember, we’d expect polar regions to see a temperature rise of 50 percent to 100 percent higher than the global average.
There is evidence that seas can rise as fast as two inches per year for decades (see
here and
here). But there may not be any true paleoclimate analog to what is projected to happen in the next century alone — temperature rise in the Arctic may well exceed 20°F by a great deal. On top of that, the West Antarctic ice sheet is grounded below sea level and considered to be unstable (see
here).
Both
ice sheet loss and sea level rise are accelerating. And analyses suggest that sea level rise could hit four to six feet by 2100 on our current emissions path. After that, sea level could continue rising five to ten feet (or more) a century until all the ice melts. And even if it takes two millennia or longer for the ice to go, we may pass the tipping point at which a total melt-out is essentially unstoppable by 2100.
For those who are unconcerned about our impact on humans living in the year 3000 and beyond, consider this. How precisely would our children and grandchildren adapt in the second half of this century to sea level rise, knowing that seas are projected to rise, say, six to 12 inches a decade for a long, long, long time? How do you build ports and coastal defenses in such a world? How do you even decide how much to spend to protect cities on the East Coast at that time, knowing the inexorable sea level rise — and ever worsening storm surges — that they face?
Hal Wanless, chair of the geological sciences department at University of Miami,
tells Nat Geo:
Quote: “I cannot envision southeastern Florida having many people at the end of this century.”
Here is a close-up of the East Coast once
Homo sapiens sapiens gets through with it:
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The West Coast is in slightly better shape but as Nat Geo explains, “In California, San Francisco’s hills would become a cluster of islands and the Central Valley a giant bay. The Gulf of California would spread north past the latitude of San Diego — not that there’d be a San Diego.”
If we let this happen, we definitely need to come up with a name to replace
Homo sapiens sapiens. I’d vote provisionally for
Homo “sapiens” sapiens, but we might consider
Fervens tardius amentes Rana, which is the best internet translation into Latin I could get for
slowly boiling brainless frog.”