I can't find the exact reason why the range is large. I'm guessing it just has to do with a general idea of the model's precision or the range given by the different runs besides "best-fit" that they did. Could even just be eye-balled. Here's all they really have about it in the text:
"For the best-fit run, transition to the large Eurasian ice sheet occurs shortly after the present (Fig. 5a). Our results therefore suggest that the actual climate system may have been geologically close (10^4–10^5 yr) to the final phase of a 50-Myr evolution from bipolar warm climates to permanent bipolar glaciation." Fig 5a shows the modeled sea-level given by the model for millions of years in the past and in the future, with an abrupt change happening not too long in the future on the timescale involved. Jason On Thu, Nov 13, 2008 at 4:36 PM, William Connolley <[EMAIL PROTECTED]> wrote: > "10,000 to 100,000 years" is an awfully big range. I thought the answer was > 50kyr, which happens to be in the middle of the range, so I'm not sure if > there is anything very new here. Anyone actually read the paper? -W > > On 13/11/2008, Eric Swanson <[EMAIL PROTECTED]> wrote: >> >> Also note the comment in the article: >> >> "In the model runs best resembling actual climate history, the switch >> to a long-lasting ice age happened as early as 10,000 to 100,000 years >> from now. However, Crowley stresses that not too much confidence can >> be placed on the results of single runs out of many." >> >> The CO2 which is now being dumped into the atmosphere would likely be >> taken up by the oceans long before the 10,000 year beginning of this >> postulated next ice age. As things are going, most of the fossil >> fuels will be burnt before the end of this century. >> >> I'm sorry to say, I think there's still a lot to learn about climate. >> And, the focus should really be on the next couple of centuries, not >> 10,000 year runs with a simplified model. >> >> E. S. >> ------------------- >> >> Alexandre wrote: >> > "Humans may have prevented super ice age" is the title of an article >> > from New Scientist. According to this article, some researchers argue >> > that "(b)efore we started pumping massive amounts of carbon dioxide >> > into the atmosphere, the planet was on the brink of entering a semi- >> > permanent ice age". Our CO2 emissions may have preventeda long lasting >> > ice age. The article states that "none of the researchers contacted by >> > New Scientist thought the model's predictions are worth taking >> > seriously". However, the idea that something like this might have >> > happened is interesting. >> > >> > http://www.newscientist.com/article/dn16026-humans-may-have-prevented-super-ice-age.html >> > Alexandre Couto de Andrade >> >> >> > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
