On Apr 16, 8:01 pm, Robert I Ellison <[email protected]> wrote: > But are tipping points predictable?
Some are and some are not. Something that varies can have both predictable and unpredictable tipping points and everything in between. Tipping points can be unpredictable due to chaotic processes or due to mere randomness. I am arguing that you need to use scientific definitions, not metaphors or the everyday meanings of terms. There are 2 different things: 1. Chaotic processes 2. Tipping points You are probably understating the importance of tipping points by confusing them with chaotic processes. > Chaos theory is a simply a > metatheory of change in complex systems and a climate 'tipping point' > is merely an example of chaotic bifurcation in a complex and dynamical > system. Not true. > Small initial changes lead to a change in one component which > drives change in another etc. A 'cascade of powerful mechanisms' > leading to a nonlinear climate response. Abrupt climate change, > tipping points, chaotic bifurcation and sensitive dependence all have > the same meaning. Not true. > > I think climate is chaotic at all time scales - in the multidecadal > timescale as > inhttps://pantherfile.uwm.edu/kravtsov/www/downloads/GRL-Tsonis.pdf There do seem to be multidecadal chaotic processes. We don't have much evidence on longer time scales. *All* time scales? Kinda a broad claim. Of course you are right that the idea of climate being the average of the weather must be bunk or an approximation of limited applicability at best. The climate parameters do keep changing on all time scales till there is no climate. > > Major climate shifts around 1910, the mid 1940's, the late 1970's and, > in a later paper(Has climate recently shifted? Swanson and Tsonis > 2009), 1998/2001. And please note that changes are evident in real > world data and are extensively documented in scientific literature. > Climate is not chaotic only in the short term - as in weather - but at > every scale from ENSO to decades, ice ages and beyond. > > Climate models are themselves chaotic > -http://www.pnas.org/content/104/21/8709.full.pdf > - suffering not only from 'sensitive dependence' but from 'structural > instability'. The latter involves chaotic bifurcation as a result of > small changes (well within the limits of quantification) of boundary > conditions. Can you give an example? I think you are confusing chaotic processes with processes that are difficult to predict because we have low accuracy of the initial conditions, but I am not sure. > There is thus no unique solution to the climate problem > within the constraints of present day understanding. Isn't that true for plenty of non-chaotic processes? > Modellers pick > their best run subjectively and send it to the IPCC where it is > graphed along with a number of other subjectively selected > 'solutions'. Very average indeed. > > So we are 'predicting' a chaotic system by means of another, and > different, chaotic system? Give me a break. 'The science' has got it > wrong at the level of underlying assumptions - mindless repetition of > the error leads us nowhere. -- 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
