There is little doubt that the WAIS and Greenland will melt eventually unless CO2 concentrations are actually made to retreat. The only question is the time scale. Since Gore did not specify the time scale, he is strictly speaking correct.
On the other hand, the viewer of AIT was left with the impression that such rises were imminent. This is fair grounds for criticism of the presentation, and indeed it was the first thing that left my lips on leaving the movie. That is not generally considered likely. There are outliers though, notably James Hansen who believes several meters in the current century under business-as-usual is to be expected. If you listen to what Gore says in detail, he merely says it is plausible. That is a defensible position. However, people respond to symbols rather than words. It may be argued that the constraints on what Gore says are distinct from those on what a scientist should say. See http://pubs.acs.org/subscribe/journals/esthag/41/i21/html/110107viewpoint_fischhoff.html A decade ago we believed that ice sheets retreat mostly by melting. This turns out to be false; land ice can simply fall into the ocean by mechanical processes with weakened ice. So recently the trend among informed opinion has been to greatly increased concern about this. The likely mechanism for retreat of the WAIS in particular is not well-constrained as to time scale. Several meters in the present century is outside the consensus expectation but within the realm of plausibility. mt --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
