More on IPCC Predictions

[IanC]

from the AR5 SOD-As discussed in 11.3.1, most of the projections presented in 11.3.2–11.3.4 are based on the RCP4.5 scenario and rely on the spread amongst the CMIP5 ensemble of opportunity as an ad-hoc measure of uncertainty. It is possible that the real world might follow a path outside (above or below) the range projected by the CMIP5 models. Such an eventuality could arise if there are processes operating in the real world that are missing from, or inadequately represented in, the models. Two main possibilities must be considered: 1) Future radiative and other forcings may diverge from the RCP4.5 scenario and, more generally, could fall outside the range of all the RCP scenarios; 2) The response of the real climate system to radiative and other forcing may differ from that projected by the CMIP5 models. A third possibility is that internal fluctuations in the real climate system are inadequately simulated in the models.

The fact of the matter is that when you adjust a model and as a consequence one part becomes more accurate and another part becomes less accurate (as did happen with their initialization techniques) that is compelling evidence that the model is suffering from exactly such problems. This is evidence that there are factors in the real world that are improperly modeled or missing entirely from the models. Given that in the same chapter the IPCC is admitting that they probably got the physics of solar variation wrong first by ignoring it entirely when they should not have, and then by including it but getting the sign of the effect completely backwards, that seems like a pretty obvious conclusion. In fact, Chapter 11 also suggests that the models are having a tough time with aerosols, Atlantic Multidecadal Variability, Pacific Decadal Variability, Interdecadal Pacific Oscillation and Walker Circulation.

In brief, the evidence that the models are getting the right answers for the wrong reasons is staring them in the face. The models can sort of kind of get the climatology right, but only for the years we already have data for. In brief, they can use 1960 data to get 2012 right, but only because we already know what the answer for 2012 should be, and the adjustments deliver it. When those same models try and make projections into the future, and then we wait a few years for the future to arrive (AR4 projections from 2007 for example are already looking way off for 2012) the matter becomes readily apparent. AR4 suggested that if no warming showed up for 15 years, the models were probably wrong. AR5 seems to provide even better evidence that they are, in fact, wrong, surrounding their projections with so many caveats that anything short of an ice age or spontaneous combustion could be said to fit within their error range.

how can anybody with an inkling of statistics and science believe that climate model projections are able to skilfully predict anything in the future?

http://wattsupwiththat.com/2012/12/23/ipcc-chapter-11-bankruptcy-protection/

 

[daveman]

You hush. We're all going to die unless we embrace world socialism.

 

[IanC]

You hush. We're all going to die unless we embrace world socialism.

we used to scoff at the USSR back in the 70's. now we seem to embrace the groupthink of failing govt policies.

 

[daveman]

You hush. We're all going to die unless we embrace world socialism.

we used to scoff at the USSR back in the 70's. now we seem to embrace the groupthink of failing govt policies.

Indeed. Progressives want the US to "progress" to the condition of the Soviet Union circa 1958 -- minus the strong military, of course.

Those who fail to learn from history are doomed to vote Democrat.

 

[skookerasbil]

WHen they can tell me exactly where a hurricane or tornado is going, then they can talk tome about temperature predictions 100 years from now. Otherwise, its BS.