Several Studies on Errors Possible in the GCM Models

The most importance is that there is little usable or in depth error analyses on the errors possible in these models.  One is from a Prod at Stanford Linear Accelerator Lab, Dr Franks dated JUl 2016.    This is best seen in the video below.   This work has been dismissed by others although not refuted.   Dr Brown also from Stanford, but the climate group took issue with the time step accumulation of error.   As a numerical simulation experienced engineer, i find this critique is unfounded and invalid. 


Dr Frank points to one of the weaknesses of the GCM models, and that is one that IPCC admits in its earlier reports that clouds remain the largest difficulty for the models. 


Although IPCC states that the GCM models are accurate to within +/- 1.64 sigma, there is no good data to support that claim.  This appears to be what one would call the precision of the models and may or may not relate to the accuracy, which simply means how close to reality is it expected to be?   Dr Franks attempts to answer this question.  It is worth noting that the IPCC in the AR5 increased its confidence in the model predictions while lowering its temperature max. 

Dr Franks uses a simple model to simulate the temperature effects as a function of the GHG forcing.   Although the basic construct is not accepted by the editors of this site, the error calculation Dr Franks preforms gives us insight.  As a simple statement of that error, he finds because of the uncertainty and therefore error in cloud formation, he finds that the error from clouds as computed is larger than the amount of total GHG forcing for the same time period.


Using his model the annual increase in forcing for the change in CO2 is +/-35 milli-W/m2 as opposed to that for clouds which is +/- 4W/m2, or 140 times larger.   So the error bars accumulate rapidly.   So the GCM cannot predict accurately even 1 year out, for the error possible is larger than that for the temp increase for the entire century.




There are other claims about the validity of this process, in essence challenging the idea of having errors accumulate with each time step.    See the comments made on these claims at this link


Section for a video or follow-on comment

We should revisit occasionally what the proper role of government is.   As the constitution was a good sense of direction, we need a core set of principles to add in order to deal with the future.


So many want to engineer society, remove risk, assist certain groups, rather than let individuals thrive and raise communities.  Why?


Is Democracy where we all "get it good and hard" or is it the best means to a free society?


Should we roll with the special interests, or make the government achieve its proper role, what is that role, and how to do this?


When do deficits and governments become too large?


Government is becoming more elitist while trying to sell corrections to problems it created, what makes this possible?


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