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Post by marchesarosa on Sept 17, 2012 0:42:26 GMT 1
An article on Roger Pielke Sr’s web site states that the draft Summary for Policymakers by UN Intergovernmental Panel on Climate Change (IPCC) has a new definition of climate change. “Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.” The past definition emphasized human caused changes, particularly activities that alter the composition of the atmosphere. Does this mean a greater recognition of human influences that are unrelated to the atmosphere (carbon dioxide) emissions? Recognition of natural causes, instead efforts to dismiss them? At this time one cannot know what will come out in the final reports. Recently, discussion of the Medieval Warm Period and the Little Ice Age has become more prevalent in the literature after being suppressed by the third IPCC Assessment Report in 2001 with its notorious “hockey-stick.” If natural causes become part of the open discussion, it will be interesting to see how government agencies such as the US EPA will handle the possibility that their pronouncements of the science being certain were, actually, uncertain. By Ken Haapala, Executive Vice President, Science and Environmental Policy Project (SEPP)
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Post by marchesarosa on Sept 17, 2012 13:36:42 GMT 1
Roger Tallbloke Tattersall puts it this way tallbloke.wordpress.com/2012/09/17/ipcc-reports-then-and-now/Third Assessment Report: 2003 “Most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”. Fourth Assessment Report: 2007“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.” Fifth Assessment Report: 2012 (draft)“Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.” It seems that the 95% confidence interval associated with the IPCC definition of “very likely” is now worth no more than a toss of the coin. How much have we been paying these people to produce “Well crafted figures and punchy take home messages“?
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Post by marchesarosa on Sept 17, 2012 13:39:46 GMT 1
“We’re 40% certain at least 30% of the weather forecasts will be at least 30% correct.”
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