On Mon, 10 Sep 2007, Fergus wrote: > I get the impression that the line tends to be: 'look, we told you > this would happen if AGW kicks in...' , which sets up the sea ice > decline as an indicator of the credibility of the hypothesis and a > verification of model projections (but as you note...)
sure. in which case the models have failed, as the obs are outside their range :-) or does only predicting too little count? > The problem I have is working out how we get from the 'what' to the > 'why'. In one sense, it really is self-evident; warmer water, less > ice. It seems to make the Polar amplification idea look fairly solid, > too. But there must be a way of applying some kind of statistical tool > to the numbers to work out the significance of the change. There > should also be a way of calculating the ration of feedback to forcing, > with the information that is now available. you can do sig tests to show that the change is not likely due to chance (cue JA...). at which point you know immeadiately its due to... solar variation! -w. > I know what you mean, though. > > > On 10 Sep, 13:32, William M Connolley <[EMAIL PROTECTED]> wrote: >> On Mon, 10 Sep 2007, Fergus wrote: >>> Things have moved fast since then, in terms of the rate of summer >>> decline. Has the process gone far enough yet for us to say, >>> definitively, that this must be an effect of AGW? Is there a numerical/ >>> statistical analysis which places recent losses beyond the possible >>> bounds of natural variability + error? >> >> Quite a few people seem to be pushing "the ice has declined faster than the >> models predict" line. So that would appear to rule out anthropogenic factors >> as >> the cause :-) >> >> More seriously, I don't think "attribution" of ice decline is done in the way >> that T changes are done. It seems to be more of the "look at this and look at >> what we predicted" kind of thing. >> >> -W. >> >> William M Connolley | [EMAIL PROTECTED] |http://www.antarctica.ac.uk/met/wmc/ >> Climate Modeller, British Antarctic Survey |07985 935400 >> >> -- >> 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. > > > > William M Connolley | [EMAIL PROTECTED] | http://www.antarctica.ac.uk/met/wmc/ Climate Modeller, British Antarctic Survey | 07985 935400 -- 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 -~----------~----~----~----~------~----~------~--~---
