> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Alberto Monteiro > Sent: Friday, May 04, 2007 1:57 PM > To: Killer Bs Discussion > Subject: RE: Re Cost of conservation > > Dan Minette wrote: > > > > I don't see any real evidence for that. The global warming will > > just continue...allowing for mass migrations to take place over > > decades instead of months. > > > You mean, because of rising sea levels? Can someone explain to me > _why_ the sea levels would increase, if the evidence is that only > the arctic ice will melt, and other ices (Antarctica, for example) > will grow due to increasing snowing? If I can do the math, > this means that sea levels will _decrease_.
The evidence for this is rather mixed....and since I'm arguing that the negative effects of global warming are not as great as the cost of full mediation, I try to use the 1-sigma high data. The effects on sea level are complex. First, there is the expansion of the seas due to the higher sea temperatures. That's the basis of the rise of 10 cm or by 2100 given in earlier estimates. This assumes that the effects on land ice masses are minimal. There have been measurements over a span of years that indicated that Antarctic ice was thickening. More recent data indicates thinning. To first order, this should be taken as neutral data, in the composite. Greenland data indicates that the movement of the glaciers may be increasing in speed. If this proves out to be a long term trend, there could be a rise of 1-2 meters in sea level by 2100. We'll have a better estimate in a few years. Finally, I wasn't thinking of sea level rise as much as changes in rainfall patterns causing changes in the regions favorable for crops...as the source for mass migration. Canada and Siberia look to be opened up, while dryer regions, e.g. immediately below the Sahara, might see less rainfall. This would promote migrations. Dan M. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
