On Jan 30, 7:54 am, Alastair <[email protected]> wrote: > On Jan 29, 5:39 am, Robert Indigo Ellison
> > By definition, abrupt climate change will happen without warning. > > Cheers, Alastair. Alastair, It is very difficult to forecast abrupt climate change and there are no precise techniques. But there are equilibria – states that tend to last for 20 to 30 years - or interannual shifts such as ENSO. Thus it can be said that the current ‘cool planet’ phase might last another decade or 2. It is a matter of assuming that the next climate shift will occur with a quasi regularity. There are repeated challenges in this forum to identify scientific departures from the so called ‘consensus’. There is a whole field of science that says that climate is dynamic and nonlinear – classically ‘chaotic’ – rather than simply driven by ordered forcing. Have a look at the Rind (1999) article ‘Climate and Complexity’ I have linked to on the site: http://pubs.giss.nasa.gov/docs/1999/1999_Rind_1.pdf “Is the climate system “complex,” and does it matter for long-range (decadal-scale) climate forecasts? The answer to the first question is definitely “yes”; the very concept of complexity originally arose in concert with atmospheric processes. To the second question, we have to answer “we don’t know.” If it is important, it will just make predictions of the anticipated climate change of the next century that much more difficult. Questions concerning the future climate in general will probably continue to be dominated by uncertainties in the radiative feedbacks. These feedbacks may be influenced by the system’s nonlinearities and the future patterns of variability, but we do not know by how much. On the regional scale, the nonlinearities might play a larger role; they also might be extremely difficult to forecast. Climate, like weather, will likely always be complex: determinism in the midst of chaos, unpredictability in the midst of understanding.” In 2010 some of us know the answer to the second question. Cheers Robert -- 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
