Bishop Hill A mysterious change of tune
Dec 10, 2013 Climate: sensitivity 
Over at Climate Audit, Nic Lewis examines the strange divergence between observational and climate-model-based estimates of transient climate response. There's lots to enjoy, particularly for the more technically minded among us. But there's also something of a mystery:
So, in their capacity as authors of Otto et al. (2013), we have fourteen lead or coordinating lead authors of the WG1 chapters relevant to climate sensitivity stating that the most reliable data and methodology give ‘likely’ and 5–95% ranges for TCR of 1.1–1.7°C and 0.9–2.0°C, respectively. They go on to suggest that some CMIP5 models have TCRs that are too high to be consistent with recent observations. On the other hand, we have Chapter 12, Box 12.2, stating that the ranges of TCR estimated from the observed warming and from AOGCMs agree well. Were the Chapter 10 and 12 authors misled by the flawed TCR estimates included in Figure 10.20a? Or, given the key role of the CMIP5 models in AR5, did the IPCC process offer the authors little choice but to endorse the CMIP5 models’ range of TCR values?
Why would all these IPCC bigwigs say one thing in the primary literature and something completely different in the IPCC report?
I just can't imagine.
Reader Comments (10)
The IPPC is primarily a political organisation with an agenda. That answers your question.
I have long since noticed that what the IPCC pundits say, and what the science in their report says, are often at odds.
But they know that 97% of the people won't take the time to read for themselves, or Think about it. (One such person told me that hundreds of peer-reviewed papers on the MWP were 'outliers').
SC, too true or put another way, IPCC reports on the science of climate change are devoid of scientific findings.
It’s the dreaded Precautionary Principle again. They assume it’s better to lean on the side of caution and keep the foot pressed on the AGW panic pedal. They’re anxious to avoid appearing uncertain because they think the public might mistake it for ignorance. Of course for practical purposes uncertainty is very similar to ignorance. Only in areas with much more data to work with is there a reasonable difference.
If sensitivity is at the low end then the public are going to be very angry because they never hear about the alternative view of the future.
The IPCC was set up by the UN specifically to use the "alleged" CO2 GHG driven global warming crisis as a vehicle for the redistribution of wealth from the industrialised countries to the developing ones.
The "science" provides the motivation for politicians and governments to sign up to the UN global initiatives. At its height of influence, the UN tried to create a global governing body to oversee compulsory climate change taxation but this failed.
The IPCC is not some free thinking, objective scientific body. It's terms of reference focus on carbon dioxide driven climate change and the resulting environmental impact. It has no interest in other climate drivers and has no purpose if climate sensitivity to CO2 is low.
Cherry-pickers.
It will be interesting to see how the "scientists" working within the IPCC manage to explain their position with the changing story as the CAGW meme collapses.
I wonder whether the BBC should bring back Jackanory and allow these people a chance to entertain the public who have been paying for their comfortable life as they have been contributing to the increse in fuel poverty.
"It will be interesting to see how the "scientists" working within the IPCC manage to explain their position with the changing story as the CAGW meme collapses."
That may well be the point of these kind of statements. I envisage a, “I was only following orders" defence for many scientists in the coming years. It's been noticeable that there has been quite a lot of hedging in the actual literature in the last few years with the policy and PR summaries being noticeably more alarmist.
I suspect that there will be more of this stuff to come. It's the kind of thing the BBC does, by producing one outlier or heretical programme on the subject that it has a devout belief in (immigration, EU, economic policy, business etc) in the case that the evidence goes against their religious fervour in a way that cannot be ignored or brushed under the carpet.
They then wheel out the program in question and say, “look! We did this program back in 2004. We are not prejudiced at all". Typical bureaucratic ass-covering technique.
Although I would describe myself as a sceptic, where climate science is concerned,
I have become more cynical than sceptical.
Why would all these IPCC bigwigs say one thing in the primary literature and something completely different in the IPCC report?
Because they make it up as they go along.