These are comments from people who's opinions on the subject should be considered. collected from WUWT
Marcel Crok: AR5 gives no best estimate for climate sensitivity; breaks with a long tradition; good news is hidden from policy makers
One of the most surprising things in the just released SPM is the absence of a best estimate for climate sensitivity. The SPM now says this:
The equilibrium climate sensitivity quantifies the response of the climate system to constant radiative forcing on multi-century time scales. It is
defined as the change in global mean surface temperature at equilibrium that is caused by a doubling of the atmospheric CO2 concentration. Equilibrium
climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence), extremely unlikely less than 1°C (high confidence), and very unlikely
greater than 6°C (medium confidence)16. The lower temperature limit of the assessed likely range is thus less than the 2°C in the AR4, but the upper
limit is the same. This assessment reflects improved understanding, the extended temperature record in the atmosphere and ocean, and new estimates of
radiative forcing. [TFE6.1, Figure 1; Box 12.2]
16 No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines of evidence
Andrew Montford at Bishop Hill:
Ducking, diving, bobbing and weaving are the general themes of the Summary for Policymakers, just released this morning.
You would imagine that the document would review what was said last time round and how things have changed since that time, but you’d be wrong. This
is, after all, the bureaucracy at work: difficulties have to be brushed under carpets and stones left unturned.
…The general theme of obscurantism runs across the document. Whereas in previous years the temperature records have been shown unadulterated, now we
have presentation of a single figure for each decade; surely an attempt to mislead rather than inform. And the pause is only addressed with handwaving
arguments and vague allusions to ocean heat.www.bishop-hill.net...
9,000 Nobel Pretenders | NoFrakkingConsensus
The unadorned truth was door number one. Cringe-worthy exaggeration was door number two. The IPCC made the wrong call.
Bob Tisdale at WUWT:
Regarding the cause of the warming, still living in fantasy world, they write:
Greenhouse gases contributed a global mean surface warming likely to be in the range of 0.5°C to 1.3°C over the period 1951−2010, with the
contributions from other anthropogenic forcings, including the cooling effect of aerosols, likely to be in the range of −0.6°C to 0.1°C. The
contribution from natural forcings is likely to be in the range of −0.1°C to 0.1°C, and from internal variability is likely to be in the range of
−0.1°C to 0.1°C. Together these assessed contributions are consistent with the observed warming of approximately 0.6°C to 0.7°C over this
They’re still misleading the public. Everyone knows (well, many of us know) their models can’t simulate the natural processes that cause surface
temperatures to warm over multidecadal timeframes, yet they insist on continuing this myth.
Apart from the usual climate-fixated organs of the MSM, it’s being barely reported. Looks like a dead cat bounce to me …
September 27, 2013 at 4:31 am
We can’t explain the increase in Antarctic sea ice extent. We have improved models that predict a decrease in extent. We don’t really know why but
we will simulate it and create a scary scenario anyway.
D.1 Evaluation of Climate Models
Climate models have improved since the AR4…………..
Most models simulate a small downward trend in Antarctic sea ice extent, albeit with large inter-model spread, in contrast to the small upward trend
There is low confidence in the scientific understanding of the small observed increase in Antarctic sea ice extent due to the incomplete and competing
scientific explanations for the causes of change and low confidence in estimates of internal variability in that region
Let’s all hope this is the last IPCC report. There is nothing useful here.
Dr. Judith Curry:
The IPCC has officially (and anti-climactically) issued the AR5 WG1 Summary for Policy Makers. I haven’t had time to go through the report in
detail, I mainly looked for these two statements. Note the changes in these two statements from the final draft discussed last week:
“Models do not generally reproduce the observed reduction in surface warming trend over the last 10 –15 years.”
“It is extremely likely that human influence on climate caused more than half of the observed increase in global average surface temperature from
These changes as a result of the ‘conclave’ this week totally dissonates my cognitives. Well, IPCC has thrown down the gauntlet – if the pause
continues beyond 15 years (well it already has), they are toast. Even though they still use the word ‘most’ in the attribution statement, they go
all out and pretty much say it is all AGW: ”The best estimate of the human induced contribution to warming is similar to the observed warming over
In case you haven’t been paying attention, ‘extremely likely‘ in the attribution statement implies 95% confidence. Exactly what does 95%
confidence mean in this context?
Douglas Fischer – The Daily Climate What we’re seeing now: Climate scientists get Swift-boated
Six years after the IPCC’s massive Fourth Assessment Report was excoriated for a handful of errors, four years after the uproar over leaked emails
put scientists on the defensive, the climate denial camp still controls the message.
Patrick J. Michaels and Paul C. “Chip” Knappenberger – Band-aids Can’t Fix the New IPCC Report
The U.N.’s Intergovernmental Panel on Climate Change (IPCC) today released the Summary for Policymakers (SPM) of the physical science volume of its
Fifth Assessment Report. The SPM is the most widely-read section of the IPCC reports and purports to summarize and highlight the contents of the
thousand-odd pages of the full report. The SPM is agreed to word by word by the international attendees of the IPCC’s final editorial meeting which
concluded as the SPM was released.
The Humpty Dumpty-esque report once claiming to represent the “consensus of scientists” has fallen from its exalted wall and cracked to pieces
under the burdensome weight of its own cumbersome and self-serving processes, which is why all the governments’ scientists and all the
governments’ men cannot put the IPCC report together again.