New paper finds climate models exaggerate projected warming

Discussion in 'Environment' started by SSDD, Dec 30, 2012.

  1. SSDD
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    SSDD Gold Member

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    In response to the barrage of recent posts by a certain member of this board, the vast majority of which reflect, and discuss nothing more than the output of computer models, I am going to post some recently published papers based on actual observation. The contrast is remarkable.

    Temperature dependent climate projection deficiencies in CMIP5 models

    This paper, published in Geophysical Research Letters finds that climate models suffer from temperature dependent biases and these biases nearly univerally result in overestimations of projections of regional temperatures.
     
  2. Old Rocks
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    Old Rocks Diamond Member

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    This does not state at all what you suggest. A 10% to 20% error, given our present lack of knowledge in feedbacks is not at all bad. Then there is the matter of the fact that the sensitivity to the warming that we are getting seems to be far greater than predicted. Arctic ice meltback where it was predicted to be 50 years from now, same for extreme weather events.

    Next time you make a conclusion from the abstract of a peer reviewed scientific article, I suggest that you post the abstract.


    Temperature dependent climate projection deficiencies in CMIP5 models

    Key Points•GCMs suffer from temperature-dependent biases
    •This leads to an overestimation of projections of regional temperatures
    •We estimate that 10-20% of projected warming is due to model deficiencies

    Jens H. Christensen

    Danish Climate Centre, Danish Meteorological Institute, Copenhagen, Denmark

    Fredrik Boberg

    Danish Climate Centre, Danish Meteorological Institute, Copenhagen, Denmark


    Monthly mean temperatures for 34 GCMs available from the CMIP5 project are compared with observations from CRU for 26 different land regions covering all major land areas in the world for the period 1961–2000 by means of quantile-quantile (q-q) diagrams. A warm period positive temperature dependent bias is identified for many of the models within many of the chosen climate regions. However, the exact temperature dependence varies considerably between the models. We analyse the role of this difference as a contributing factor for some models to project stronger regional warming than others by looking at the entire ensemble rather than individual models. RCP4.5 temperature projections from all GCMs for two time periods (2021–2050 and 2071–2100) are compared against a linear fit to the 50% warmest months from the respective q-q plot for each model and region. Taken together, we find that in general models with a positive temperature dependent bias tend to have a large projected temperature change, and these tendencies increase with increasing global warming level. We argue that this appears to be linked with the ability of models to capture complex feedbacks accurately. In particular land-surface atmosphere interactions are treated differently and with different degree of realism between models.

    Temperature dependent climate projection deficiencies in CMIP5 models
     
  3. Mad Scientist
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    Mad Scientist Deplorable Gold Supporting Member Supporting Member

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    Even Obama admits it's all an Economy Crushing Scam!

    Suck it Warmist Nutters! :lol:
     
  4. Old Rocks
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    Old Rocks Diamond Member

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    My, another peer level poster for Crudader Frank.
     

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