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"All models are wrong but some are useful". I am not against the concept of anthropogenic climate change because climate models may not be strong source of information for climate change. Observation data in the last 30 years or more are enough to prove that human related emissions are affecting the radiative and thermal properties of land, ocean and atmosphere. This question is about climate models which are based on approximations in so many ways. I am deeply concerned that most modelers tune their models for the right or wrong reasons to produce "quality" publications on peer-reviewed journals. They seem to say, "look at my model, it perfectly reproduced what is observed". But we know that, there are so many approximations for turbulence, micro-physics, land surface fluxes, and so forth. The numerical solution approximation by itself imposes serious limit to the accuracy of climate models. Some manuscripts that I found are "too accurate to be true". Then my question is how accurate can a climate model be? Are there methods to check the accuracy of those publications claiming to be true?

Edit: This question is broad and it requires broad answer based on uncertainties imposed on climate models by approximations at each level of the model development and indicate the maximum achievable accuracy level. In my mind something like the following conceptual figure.

Warning: The following figure is not based on any study or realistic data. It is just something I have produced for something the answer to my questions may look like. enter image description here

Gemechu Fanta Garuma
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    It would really be helpful if you pointed out which studies you are dissatisfied with. Most climate model groups use many different emissions scenarios to see which is most accurate. Also, see https://earthscience.stackexchange.com/questions/2162/how-good-were-climate-models-of-the-1990s-at-predicting-the-global-temperature-t?rq=1 – f.thorpe Feb 09 '17 at 00:31
  • @ferrenthorpe Yes, they use emission scenarios, RCP4.5, RCP6.0, RCP8.5. All the scenarios give different results and that's not my point. The point is how accurate should they be given all those approximations involved during the modeling stage? Some seem more accurate to believe in or the uncertainties from such approximations are compensated for by other corrections. Are these corrections right? – Gemechu Fanta Garuma Feb 09 '17 at 01:04
  • I am questioning validation for the current climate and not future projections that use RCP scenarios. – Gemechu Fanta Garuma Feb 09 '17 at 01:13
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    I really think you should point out at least a couple examples of which studies you are concerned with. Otherwise it's just speculation on our part. Models have been tuned more and more as the science advances. Reproducing a global temperature curve is not hard... it's one big average. Though, I've never read a paper that claimed their model was perfect. If you dig in, you will see that those same climate models have difficulty reproducing spatial variability. – f.thorpe Feb 09 '17 at 03:09
  • This question is way too broad at the moment, the answer will be different depending on the variables and the time/space scales. Farrenthorpe's right, some examples would be useful. That said, there are some possibly relevant recent discussion papers in this area: Baumberger et al and Hourdin et al. – Deditos Feb 09 '17 at 14:15
  • @Deditos Thanks for the link to the papers. Baumberger et al. (2017) touches the problem from philosophical perspective and clearly states the problem I have raised above. Hourdin et al. (2017) raised the same concern but suggested tuning the model could be right or wrong but conveyed the message that the modelers should be transparent as to what they do to their models. But modelers keep somethings mysterious. I want somebody to tell how would the mystery behind every data from those models be known. – Gemechu Fanta Garuma Feb 09 '17 at 20:20
  • I want the question as it is. I think, it is not fair to pick one or two study/ies out of a pull of so many that have the same characteristics. – Gemechu Fanta Garuma Feb 09 '17 at 20:21
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    @GFG ok, well, in that case it's too broad. – 410 gone Feb 14 '17 at 08:57
  • @EnergyNumbers Yes, I want a broad answer too, an answer which indicates the uncertainties at each approximation level and the approximate maximum accuracy level that can be achieved by GCMs and RCMs. – Gemechu Fanta Garuma Feb 15 '17 at 02:37
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    A climate modeling expert should be able to answer this question. Some statements in it may need some support but I do not think the question is too broad. The question also hints at confirmation bias, which I know is an existing and insidious problem in Earth sciences (and I assume others too). – milancurcic Feb 15 '17 at 15:15
  • @milancurcic Yes, climate modelers should answer this question. Otherwise, it is quite difficult to rely on most of the studies that have used climate models for adaptation and mitigation policies. The quality of the models should be explicitly quantified based on the underlying approximations and on the basis of the developed physical sciences. – Gemechu Fanta Garuma Feb 21 '17 at 17:50

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