Recently there has been discussion of exaggerations and possibly misleading documents. In November RealClimate posted the Copenhagen document for discussion. I raised the following questions, which were posted but got no reply.
Sea level hyperbole Copenhagen report/IPCC
"Sea-level prediction revised: By 2100, global sea-level is likely to rise at least twice as much as projected by Working Group 1 of the IPCC AR4, for unmitigated emissions it may well exceed 1 meter. The upper limit has been estimated as - 2 meters sea-level rise by 2100. Sea-level will continue to rise for centuries after global temperature have been stabilized and several meters of sea level rise must be expected over the next few centuries."
There is nothing I can find in the body of the report that shows a possible 2 meter rise by 2100 (see the table on p. 40). Yet the conclusion states "an upper limit of 2 meters." Why? There are three studies cited on the table. Quoting from one of them:_"Šthis relationship results in a projected sea-level rise in 2100 of 0.5 to 1.4 meters above the 1990 level."_Rahmstorf 2007 http://www.sciencemag.org/cgi/content/abstract/1135456
My understanding is that the current rate of increase is about 30 cm per century.
IPCC 2001 projected a range of 11 - 77 cm increase.
New evidence projects a range of 50 - 140 cm.
(For Americans like myself, that means that the rate of sea level rise is expected to increase from the current 1.2" per decade to somewhere between 2" - 5.5" per decade.)
Is there some evidence that makes the higher range more probable? Where does the "upper limit of 2 meters" come from? Why did the authors put this high number, and indeed one not even presented in the body of the work, in the Summary? Is it simply not sourced (i.e., no reference to the supporting research)? Or is it a case of overstating the scenario?
I would be curious about your views on the likely sea level rise, and about the strength of the underlying evidence.
I freely admit that as a layman, I could be simply misunderstanding the documentation, or misreading the evidence. So I submit this to your expertise!