blimey, bust the answer already...
costing more than the combined losses in the credit crash and the Euro crisis while actual measured figures are within normal parameters is not a rational reaction. Of course without actually about an 80% drop in industrialisation nothing noticeable would be achieved, (as if that was a good thing), so you would basically wreck the quality of life for everyone for some imaginary threat.
http://ate.entrewave....pproject/pproject.htm
Here is a complete list of figures for around the last 200 years. OK, I know they don't give their sources, but the actual figures are familiar to me so better to be all on one page than loads of links.
Glad to say my sea level diagrams are pretty universally used outside Steven Goddard's site and found them on Wikipedia, again nicely presented on one page.
http://en.wikipedia.org/wiki/Sea_level_rise
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So just staying in the present (I know it's hard but hang in there), after a 50% rise in CO2 the fairly steady rise in temperature and sea level would give about a 10 inch rise and 1C rise by 2100. Now I have no computer running, or even a pen and paper- I was able to do that in my head.
The Greenpeace (not IPCC, they are far more reasonable) and Monbiot scenarios are a 6-10C rise with a corresponding 1-5M sea level rise.
That would require an exponential rise in temperature (from a linear rise in CO2 which has continued from 300-390ppm on a pretty straight angle appearing to remain there or thereabouts on existing known trends) and possibly an exponential rise in CO2 to kick in to help it.
As yet neither have happened, and without at least a small beginning of a rising slope (above 45') for even one parameter then my figures based solely on a linear relationship are the betting man's choice for 2100. Anything else is on the edge and would be in the hundreds to one scenario. Probably millions actually but unless we're all here in 2100 we'll never have a clue.