'The one thing that they do not want to have to admit is that they exaggerate the amount that the earth’s average temperature will increase as a result of human greenhouse gas emissions. If the models are overheated, then so too are all the projected impacts that derive from the model projections—and that would be a disaster for all those pushing for regulations limiting our use of fossil fuels for energy.
It is clearly not a good situation for climate models when even a sustained temperature rise equal to the fastest yet observed (Scenario 3) still leads to complete model failure within two decades.'
'The magnitude and sign of the future carbon balance of the Arctic are highly uncertain...some models showing Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral.'
'We have been building models and there are now robust contradictions,' says Liu, a professor in the UW-Madison Center for Climatic Research.
Proceedings of the National Academy of Sciences: '....describe[s] a consistent global warming trend over the course of the Holocene, our current geological epoch, counter to a study published last year that described a period of global cooling before human influence. The scientists call this problem the Holocene temperature conundrum. It has important implications for understanding climate change and evaluating climate models, as well as for the benchmarks used to create climate models for the future.'