Fifth IPCC Climate Change Report Released
The long awaited full text report is finally available. The Final Draft Report, dated 7 June 2013, of the Working Group I contribution to the IPCC Fifth Assessment Report Climate Change 2013: The Physical Science Basis was accepted but not approved in detail by the Twelfth Session of Working Group I and the Thirty-Sixth Session of the IPCC on 26 September 2013 in Stockholm, Sweden. This report consists of the full scientific and technical assessment undertaken by Working Group I. While the final draft of the underlying Working Group I report is still subject to copy-editing and corrections in proof as normally applied to scientific reports the fundamental tone and content of the report has been set. No screaming warnings; no predictions of impending doom. The most shocking thing is that our knowledge of climate change has not advanced in almost a decade. Simply put, climate scientists are puzzled by the way nature is acting.
The Final Draft Report has to be read in conjunction with the document entitled “Climate Change 2013: The Physical Science Basis. Working Group I Contribution to the IPCC 5th Assessment Report – Changes to the Underlying Scientific/Technical Assessment” to ensure consistency with the approved Summary for Policymakers (IPCC-XXVI/Doc.4) and presented to the Panel at its Thirty-Sixth Session. This document lists the changes necessary to ensure consistency between the full Report and the Summary for Policymakers, which was approved line-by-line by Working Group I and accepted by the Panel at the above-mentioned Sessions. You can find the full PDF (166MB) online or go to the IPCC website.
The report does its best to put a brave face on an uneventful climate. For example, consider this statement from the Summary for Policy Makers (SPM):
Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.
Obviously, the measurement period has been expanded in an attempt to hide the 15 year plateau in global temperatures. Some of the verbiage has been softened between the many drafts and the final release. Bob Tisdale has a nice comparison between some of the different versions on his website. Even so, leaked or released versions of the SPM contain a number of nuggets, like:
- No increase in hurricanes (tropical cyclones) and drought: “Low confidence” in both a “human contribution to observed changes” and “likelihood of future changes.”
- “There may also be ... an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing”
- “Due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends”
- “Models do not generally reproduce the observed reduction in surface warming trend over the last 10–15 years.”
More will be revealed as the body of the report is examined in detail. In the meanwhile, warmists are spinning like mad, claiming the new report does not back down from the conclusions of the previous AR4. Even if that were so, it would mean that the IPCC has not advanced in seven years, despite the efforts of thousands of scientists and the spending of billions of dollars. During that time the climate science community's main product has been a constant stream of propaganda aimed at frightening the public.
Naturally, global warming skeptics are having a field-day with the new reports. “Unless global temperature will begin to rise again in the next few years, the IPCC is very likely going to suffer an existential blow to its credibility,” said Benny Peiser, director of the Global Warming Policy Foundation.
Judith Curry, professor and chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, was even blunter: “IPCC has thrown down the gauntlet – if the pause continues beyond 15 years (well it already has), they are toast.”
The main take home point seems to be that the core scientific understanding remains unchanged. Roger Pielke Jr., professor of environmental studies at the Center for Science and Technology Policy Research at the University of Colorado, details this and a number of other interesting observations on his website under the title “Five Points on the IPCC Report.” As Dr. Pielke put it: “The release of the IPCC's Fifth Assessment Report should give anyone following the climate issue a deep sense of deja vu, if not a full-on case of Groundhog Day syndrome. We have seen this all before.”
What are those humans on about?
All scientific double speak and political spin aside, there is no way to describe the latest report as anything but a backing down from the previous climate catastrophist position. In short: they overestimated the importance of CO2; there is no increase in storms or drought; trends have been estimated from measurements taken over too short a period of time; and the computer models do not work.
Be safe, enjoy the interglacial and stay skeptical.
If anyone doubts that the presentation of information in AR5 has been skewed, consider the figure below that did not appear in the final report. The figure makes it painfully obvious that the IPCC's model predictions, even for the most modest scenarios, are wrong. The comments provided are from Steve McIntyre at Climate Audit.
AR5 Second Order Draft (SOD) Figures 1.4 and 1.5 showed the discrepancy between observations and projections from previous assessment reports. SOD Figure 1.5 (see below as annotated) directly showed the discrepancy for AR4 without additional clutter from earlier assessment reports. Even though AR4 was the most recent and most relevant assessment report, SOD Figure 1.5 was simply deleted from the report.
The figure clearly shows that the recent temperature trend has been below the lower confidence interval for all the AR4 scenario predictions. Calling this report disingenuous would be a kind understatement, calling it perfidious warmist propaganda would be more accurate. For a detailed explanation see Steve's blog post.