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.

IPCC report

weird how you can view the rise in CO2 to possible levels >500 ppm without any doubts...@>500 ppm the ice sheets will melt and clathrate CH4 release will occur and create a feed back loop....the 500 ppm threshold will definitely sign of any hold back on emmissions...and the experiment will give us all a result...

Lack of sensitivity

"No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines of evidence and studies." IPCC WG1 SPM-11

agreement on PPM CO2

...whatever is put forward as an alternative to Global Warming there is one data point that is agreed....CO2 >500 ppm = no ice at the poles....this is the findings of so many studies and if you want to check then he most consolidated evidence and references is to be found in Dr William Ruddimans books...nothing can be said with any authority if this CO2 >500 ppm marker is not considered...and there is no doubt in my mind that the Earth will see CO2>500 ppm before there will be a way or the other.

Not really

Your assertion that an atmospheric CO2 level of 500ppm is sufficient to remove all ice from the poles is not correct. Earth has had ice on the antarctic continent for around 25 million years, and on Greenland for nearly that long. During that time CO2 levels have made excursions above 450-500ppm and the ice remained intact. Simply jacking up atmospheric CO2 levels is not a sufficient condition to melt the polar ice. Even the IPCC admits that, under its worst temperature scenarios, it would take thousands of years to melt the ice on Greenland. Antarctica, which is thermally isolated from more tropical latitudes by the circumpolar circulation, would take much longer. In short, even if such an increase of atmospheric carbon dioxide takes place, you will be long dead before the ice melts away.

Moreover, there is no reason to think that artificially elevated CO2 levels will cause a commensurate amount of temperature rise as compared with the paleoclimate record. In a study of Paleocene temperatures and CO2 levels, which were higher than current levels, Royer et al. stated what most scientific studies have discovered: “These results suggest that factors in addition to CO2 are required to explain these past intervals of global warmth.” Even the “sudden” temperature rise (~6°C) during the PETM—a period where CO2 levels went significantly higher than 500ppm (1500-2000ppm)—took 10,000 years to occur and lasted for 100,000 years. This was perhaps the last time there was no polar ice. Sluijs et al. also found that CO2 on its own is insufficient:

Increasing temperature and sea level match expectations based on palaeoclimate model simulations, but the absolute polar temperatures that we derive before, during and after the event are more than 10 °C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds or hurricane-induced ocean mixing—to amplify early Palaeogene polar temperatures.

My next blog post will expand on why rising carbon dioxide levels alone are not sufficient to recreate climate conditions from the past, even the geologically recent past. The IPCC based their whole case for anthropogenic global warming leading to catastrophic change on CO2 levels. There is mounting evidence that this view is wrong. The truth is we do not know what an artificially induced rise in atmospheric CO2 will do. To say otherwise is foolish in the extreme.

the 500 ppm marker

I can also say that perhaps the whole CO2 criteria might be explained by the production of CO2 from the ocean as it heats up due to other leading factors (solar irradiance , milankovitch cycles etc etc) but my point is that 500 ppm will be reached within our life time...the experiment with the climate presently working in the middle east and the emissions are unrestricted...have been to China ...emmissions unrestricted...the futile attempts by the US EU IPCC etc etc are a bit like bringing a dust pan and brush to an earthquake....totally ineffective (and very expensive also) one really cares unless you have votes involved and even then... jobs and cheap fuel are what people want both in the West as well as in the developing world (where poverty drives all environmental concerns completely out the window). Crossing the 500 ppm parameter the Climate goes in the direction of Cretacous and PETM event when and where this will one knows exactly of course...but "something" will happen...My opinion is that the planet has two vital processes...Emmission and Absorption..of gasses, liquids, vapours and solids....Emmissions give us energy and Absorption gives us food and forests...clearly we are erring on the side of emmissions...and if you look at the benefits of Absorption reminds me of the tale of the goose that laid the Golden eggs...keep Emmitting pollutants and you will get the immediate benefits but later on the system gets choked..(check out Lagos or Cairo or Beijing)...but if we make a war effort to encourage Absorbtion processes...we will get golden eggs forever ...look at the fisheries and forests that are being promoted and preserved..and that is my stance on this subject having seen it from both sides in my work and travels (as much as my job as a Geologist)


I think you need to pay closer attention to facts. Rain forests are on the rebound, due mostly to the increase of CO2, not idiotic gov't regulation. To use the term 'pollutant' when referring to CO2 is to turn your otherwise thoughtful comments into mush. To confound what happens in cities (some) with the ecology of the planet is to muddy the waters.

It would seem to me that the only thing the Green movement and the AGW Alarmists are out to protect is the property values of the 1%. The fact that all their 'solutions' bring crushing poverty to many or leave many in that state seems totally irrelevant to them. If the gamble is for clean water today or what might happen in 100 years, I'll take the clean water today with prosperity and count on technological advances to solve the technical problems and stop politicians and elites from making money by using tax payer dollars to subsidize schemes that wouldn't stand a chance without coercion.

500 ppm

yes..Rain Forests , fisheries, coral rees and many other absorption processes will work to balance the emmissions sent out by volcanoes, facotories , power stations etc and that is just what you expect as stated and the green movement (as said by no less a person than the co founder of green peace who has now resigned in disgust) ...that "refugees from the old communist ideology are flocking to the environmental movement" BUT my point is that 500 ppm CO2 is unchartered territory and so long as the proverbial bus is not going to run us overtomorrow...we will see it...any arguement for and against emmissions is just meaningless because we will see a result...and then we will know what this crazy experiment in jacking up the CO2 levels actually does...because no one is going to stop the big burn

Floods and drought

From AR5, Observations of Water Cycle Change:

The most recent and most comprehensive analyses of river runoff do not support the AR4 conclusion that global runoff has increased during the 20th century. New results also indicate that the AR4 conclusions regarding global increasing trends in droughts since the 1970s are no longer supported.

So much for claims of increased flooding and droughts. Even the IPCC denies it!


Very ordinary science "fiction" that's about all <:o)