My guess is that part of the problem is that there haven't been any physical examples to compare models to until now. In other words, if the task is to predict the dynamics of large melting ice sheets, it's a lot easier if you've got the past behavior of large melting ice sheets to study.
But since the last time any of these ice sheets were melting like they are now is thousands (or hundred thousands) of years ago, we haven't had any good past behavior to check models against. Of course, we're getting lots of good info now... On 2/7/07, William M Connolley <[EMAIL PROTECTED]> wrote: > > > > On Wed, 7 Feb 2007, [EMAIL PROTECTED] wrote: > > If sea level rise is the major concern, and the big uncertainty is ice > > sheet dynamics, I wonder why so little seems to be getting done to > > resolve the uncertainty. Presumably, there's value in knowing whether > > Give us more money! > > > sea level will rise by 5 m in 50 years starting in 2030, or whether > > it'll only rise by 40 cm by 2100? Why isn't more research focused on > > ice sheet dynamics, if we believe (do we?) that they are the key > > uncertainty for sea level rise, and that sea level rise is the key > > danger? > > Or, more seriously, yes people are working on the ice dynamics. > > You could probably make a case for the idea that SLR from thermal > expansion is > boring and bound to be fairly small, although not negligible. By contrast, > SLR > from ice sheets is far less well determined. It could be tiny (or even > negative) > but potentially might be much bigger than the thermal exp component. > > > And, a phrase like "ice sheet dynamics are poorly understood" does not > > communicate to me whether Greenland's ice sheet could literally slide > > into the sea within a few hours, once some tipping point is reached, > > or whether the disintegration must at the very least take decades. If > > it's the latter, why exactly? > > People seem to have shifted their ideas a bit on what holds ice streams > back; > and the chances of them moving faster seem to have increased. But (having > talked > at cross-purposes with glacios a few times) they don't seem to be able to > give > useful timescales. > > -W. > > William M Connolley | [EMAIL PROTECTED] | http://www.antarctica.ac.uk/met/wmc/ > Climate Modeller, British Antarctic Survey | (01223) 221479 > > -- > This message (and any attachments) is for the recipient only. NERC is > subject > to the Freedom of Information Act 2000 and the contents of this email and > any > reply you make may be disclosed by NERC unless it is exempt from release > under > the Act. Any material supplied to NERC may be stored in an electronic > records management system. > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
