Reposted from Richard Tol’s blog
I welcome the inquiry by the Select Committee into the Intergovernmental Panel on Climate Change. The focus of the inquiry is on Working Group I of the IPCC and its Fifth Assessment Report, neither of which are in my core areas of experience and expertise. I was a contributing author to IPCC WG1 AR3; I was a lead author in a few reports of WG2 and WG3; I am currently a convening lead author for WG2 AR5. I will therefore address only a few of the issues raised by the Select Committee.
· How effective is AR5 and the summary for policymakers in conveying what is meant by uncertainty in scientific terms ? Would a focus on risk rather than uncertainty be useful?
The agreed distinction between risk and uncertainty goes back to Knight (1921), with risk characterized by known probabilities (the throw of a dice) and uncertainty by unknown probabilities. Climate change is better described by uncertainty than by risk. In other arenas the IPCC has tried to redefine widely accepted concepts (e.g., vulnerability) which has led to endless, fruitless discussions on semantics. It would be regrettable if the IPCC would repeat this mistake with regard to risk and uncertainty.
· Do the AR5 Physical Science Basis report’s conclusions strengthen or weaken the economic case for action to prevent dangerous climate change?
IPCC WG1 AR5 is silent on this matter. The IPCC cannot make a case for action without violating its mandate; and if anything, such a case would follow from an assessment of the material in the reports of all three working groups. The IPCC cannot assess whether climate change is dangerous or not, because “danger” is a value-laden concept that, per Arrow (1962), cannot be defined for a society.
· What implications do the IPCC’s conclusions in the AR5 Physical Science Basis report have for policy making both nationally and internationally?
None. IPCC WG1 AR5 has added little to AR4 that would shift the established positions on climate policy, either nationally or internationally.
· Is the IPCC process an effective mechanism for assessing scientific knowledge? Or has it focussed on providing a justification for political commitment?
Neither. The IPCC process assesses scientific knowledge according to a political time-scale. That implies that parts of the literature are assessed too frequently while other parts of the literature are not assessed frequently enough. Instead of a mega-report every 6-7 years, it would be better to have an IPCC Journal with frequent updates where the literature moves fast and infrequent updates where little new is written.
Political positions are driven by power relations and the views of the electorate. The typical voter does not read the IPCC reports, but only casts a glance at what some journalist made of the IPCC press release.
The IPCC reports do justify the existence of a large bureaucracy which, judging from the lack in progress in reducing greenhouse gas emissions and vulnerability to climate change, seems primarily occupied with maintaining and expanding said bureaucracy.
· Is the rate at which the UK Government intends to cut CO2 emissions appropriate in light of the findings of the IPCC AR5 Physical Science Basis report?
Per Weitzman (1972), the UK should set an appropriate trajectory for a carbon price, rather than for greenhouse gas emissions. If the UK chooses to persist in its mistake of emissions targets, it should inform that decision with an assessment of the reports of all three working groups, and particularly WG3.
· What relevance do the IPCC’s conclusions have in respect of the review of the fourth Carbon Budget?
None. At a stretch, IPCC WG1 AR5 may have something to say about a long-term global carbon budget. However, a decade of British emissions is very small relative to a century of global emissions.
The UK could be a leader in international climate policy if it would demonstrate that greenhouse gas emissions can be cut substantially without causing economic pain. Current UK climate policy shows the opposite: Climate policy can cause real hardship without making a dent in emissions.
Tallbloke's Talkshop 
cagey or what……
Richard,
Thank you for posting this. Your conclusion is clear and rational. Which in this day and age raises the question of how the climatocracy wil respond to you….
The final line is where the rubber meets the road. Large costs for no benefit, even granting the false premise that reducing emissions is desireable.
Why does anyone take this pompous nitwit seriously? He says:
“The UK could be a leader in international climate policy if it would demonstrate that greenhouse gas emissions can be cut substantially without causing economic pain.”
He seems to think that greenhouse gas emissions (darbon dioxide) are a problem. Does he have a shred of evidence to support this assertion?
All the real world proof is hiding at the bottom of the deep, blue, sea. Or SLT.
How convenient of it…..
“All the real world proof is hiding at the bottom of the deep, blue, sea. Or SLT.”
I don’t agree. I very much believe it lies at its surface in plain sight. One just needs to see it. For seeing it one would recommend to download the ARGO Global marine atlas with the data and plot the ocean surface layer temperatures (one can do it in layers of course, the resolution is ~5m). Then one – who is able to realize the ocean is the thing covering the 2/3rds+ of this planet – can see immediately there is no global warming whatsoever since the very beginning of the ARGO era and that the real sea surface layer temperature (unlike the HadSST3 “anomaly”) quite meticulously follows the insolation changes and the layer temperature varies much more, making nice almost sinus curves. It works for the globe, it works for the hemispheres, it works for tropics, moderate zone, high latitudes. It must work when one considers how high are the insolation changes during the year (many dozens of W/m2) there’s really by far nothing else which would supersede this influence. One can also plot the temperature change profiles going deeper and if one knows what one is doing one will discover there is a whole temperature history written in the ocean – at least couple of decades of slowly progressing heatwaves.
For policy makers in the Great Britain and all at the Northern hemisphere the key message from the ARGO is that the ocean at the northern hemisphere (unlike that more insolated at the southern hemisphere) despite huge inflow of warm water from the southern hemisphere (especially at the surface) already managed to cool itself not only in the surface layer but all the way down to the deepest level measured by the ARGO (~2000m) and the reason was, simsalabim: the melted ice there up in the Arctic and all the heat it took. So if one glances at the current level of the solar activity and the predictions of it, there’s no prospect of warming at the Northern hemisphere in sight – at least not for the remaining lifetimes of the current policymakers. But I of course know, that real data, not speaking understanding them, is the last thing the IPCC and the policymakers are interested in, so it will take another years for them to realize they wasted trillions for chasing a phantom.
Jeez Louise. RU really humourlessly so lacking in insight you didn’t get it? I assumed the abbreviation for “Something Like That” would have been enough clue even for those like you.
Oh, well.
Be fair Brian, without prior knowledge of you and your intent it would not be possible to suggest you were writing ‘tongue in cheek’.