Gareth wrote: > On Feb 9, 3:17 pm, James Annan <[EMAIL PROTECTED]> wrote: > >> Crops are grown on an annual cycle, >> machinery only last a few years (in fact astonishingly little time on >> efficient agribusiness, as reliability and peak performance are critical >> factors). > > True for some crops, but not for tree and vine crops. A vineyard costs > a lot to establish (posts, wire, irrigation) and takes 5 years to > reach full production, 10 years to optimum quality.
Granted. Perhaps my UK bias is showing, as there isn't much of either there. I suppose there are some currently marginal areas of the UK where vines could plausibly be planted now in anticipation of increased warmth, but I suspect it is a rather marginal effect. >> [To be clear, I'm talking not about pushing seasonal forecasting up to >> the 5 year time scale, but more like interpolating the 100 year climate >> change scenarios down to perhaps 20 years.] > > I think money spent on multi-year to decadal forecasting would be > extremely well spent. Only if it gives better skill than climatological persistence! > >> The papers I alluded to earlier present 90% confidence intervals of >> 0.3-1.3C and 0.5-1.1C over the 30 year interval 1990s-2020s. That is, >> they are centred on 0.8C in 30 years, which I (and indeed the IPCC) >> think is unreasonably high > > Wasn't there a recent paper suggesting that warming & sea level rise > was actually tracking the high end of IPCC projections? Rahmsdorf? > Can't find the reference, and I'm supposed to be doing something > else... That'll be this: http://www.sciencemag.org/cgi/content/abstract/1136843v1 which claims a temperature trend of ~0.21C/decade since 1990, but arguably this is slightly cherry-picked due to the inclusion of Pinatubo near the start of this interval. (Just to be clear: I'm not saying what they did was unreasonable, but an analysis that compensated for the a priori random but a posteriori identifiable effect of Pinatubo would have indicated a lower anthropogenically-forced trend.) Even so, significant acceleration is necessary to reach 0.8C over a 30 year interval - especially noting that we are already part-way through it. Possible? Sure. 50% probability? I wouldn't say so. Here is something I plotted earlier, which has some relevance: http://julesandjames.blogspot.com/2005/06/predicting-climate-change-2.html James --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
