The full text of the IPCC’s Fifth Assessment Report has been out for less than 24 hours and the tales of malfeasance are flowing already. Steve McIntyre has already blogged about some misleading behaviour by senior scientists involved in the review, but his post this morning is amazing, revealing how the discrepancy between climate models and observations was systematically hidden between the final review of the draft and the report issued to the public. --Andrew Montford,
Bishop Hill, 1 October 2013
For the envelopes from the first three IPCC assessments, although they cite the same sources as the predecessor Second Draft Figure 1.4, the earlier projections have been shifted downwards relative to observations, so that the observations are now within the earlier projection envelopes. You can see this relatively clearly with the Second Assessment Report envelope: compare the two versions. At present, I have no idea how they purport to justify this. None of this portion of the IPCC assessment is drawn from peer-reviewed material. Nor is it consistent with the documents sent to external reviewers. --Steve McIntyre,
Climate Audit, 30 September 2013
Since 1997, there has been no significant increase in global average surface temperature, and some areas — notably the Northern Hemisphere — have actually cooled. The U.N.’s Intergovernmental Panel on Climate Change (IPCC) has limited the hiatus to 10-15 years. Anastasios Tsonis, distinguished professor at the University of Wisconsin – Milwaukee, believes the pause will last much longer than that. He points to repeated periods of warming and cooling in the 20th century. “Each one of those regimes lasts about 30 years … I would assume something like another 15 years of leveling off or cooling,” he told Fox News. --John Roberts,
Fox News, 30 September 2013
[At the Stockholm IPCC meeting] participants debated extensively the SPM text dealing with simulated and observed trends in global mean surface temperature in the long and short term. Co-Chair Stocker emphasized the need to address discussions currently taking place among policy makers regarding the past 10-15 years and said that “now is the time for the IPCC to make a statement to the outside world.” The US said that a period of 10-15 years is too short for model evaluation. The most contentious point concerned differences between simulated and observed short-term trends. The US, Austria, Saudi Arabia, the Russian Federation, Germany, Belgium and others supported reference to 10-15-year periods in general. China maintained that reference should only be made to the past 15 years. On the explanation of the observed reduction in the surface warming trend over the period 1998-2012, Saudi Arabia strongly urged incorporating language from the Technical Summary on models overestimating the warming trend. The CLAs advised against including this statement in the SPM, noting that: the research is currently inconclusive; overestimation of the models is too small to explain the overall effect and not statistically significant; and it is difficult to pinpoint the role of changes in radiative forcing in causing the reduced warming trend, with Co-Chair Stocker referring to this issue as an “emerging science topic.” --
Earth Negotiations Bulletin, 29 September 2013
