‘Data from observation says global cooling. The physical model says it has to be warming’
'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.'