The climate views of an independent physicist

This results in part from the ambiguity inherent with asking scientists to express themselves consensually on what they think is the best message. There is a need to produce a scientific summary addressed to scientists and giving an objective picture of our knowledge and ignorance in climate science, with emphasis on the issues that are less well understood and what it implies to clarify them. 

 

Such a summary should pay particular attention to a number of contentious issues that have been identified by a number of climate scientists who do not share the alarmist interpretation of the science. 

 

In the short term, the IPCC report weakens the case for taking urgent action. In the long term, it supports the importance of taking global warming as an important factor in decisions affecting the future of the planet, together with energy policy, management of natural resources, social, financial, economic and geopolitical considerations.

 

1.              Late September the IPCC published Climate Change 2013: the Physical Science Basis, a document of over 2200 pages, which will be read by very few people, and an accompanying “Summary for Policymakers” (SPM) of 36 pages, which will be the document that is generally read by politicians, officials and the media. In my opinion the main point to appreciate is that as it has the purpose of addressing policy makers, the SPM can not be a scientific document. When writing the SPM, the authors are facing a dilemma: either they speak as scientists and must therefore recognize that there are too many unknowns to make reliable predictions, both in the mechanisms at play and in the available data; or they try to convey what they “consensually” think is the right message but at the price of giving up scientific rigour. They deliberately chose the latter option. The result is they have distorted the scientific message into an alarmist message asking for urgent reaction, which is quite contrary to what the scientific message conveys.

2.              Most scientists who contribute to the IPCC work enjoy the intellectual integrity that is supposed to be inherent to scientific ethic. They are well aware of the high degree of uncertainty that is attached to their predictions. However, one should not have asked them to state what they think is the right message; or at least, one should not have asked them, as scientists, to do so. Doing so is a highly subjective exercise that depends heavily on the weight that one is prepared to give to the principle of precaution. Anyone who has responsibility understands that the principle of precaution is a good thing if it is used wisely. It is not surprising that most IPCC contributors prefer to stay away from the political debate, with which they do not feel at ease; it is natural that they think “I have done my job as a scientist, it is not up to me to take political decisions, but if you really insist, I prefer to be on the safe side because I do not think that it can harm to reduce our C02 emissions, while I cannot exclude that it may harm to increase them to some high level”. Of course, they think as scientists and are miles away from realizing that in fact it does harm when it leads to wasting enormous amounts of resources by taking wrong decisions, such as investing billions of dollar in electric cars or in large windmill farms, to quote just two examples. But these are problems of economics, which they consider not to be their business. Professor Judith Curry is rightly critical of the misleading impact of the concept of consensus the way it has been used by the SPM2.

 

3.              What we are witnessing are successive distortions of the scientific message of the AR5 report on the Physical Science Basis: first from the report to the SPM by those who wrote and/or amended the SPM, then from the SPM to the press by those who speak in the name of the IPCC (including the IPCC chairman) then from the press to the general public by green activists who too often behave irresponsibly in misrepresenting the findings of the work.

 

4.               It is wise to pay attention to the possible damage that anthropogenic C02 emissions may imply for humanity. We have become conscious over half a century of the fragility of the planetary equilibrium that is necessary for our survival. Actions that may be necessary cannot be decided in an atmosphere of panic and under the pressure of urgency. They require deep thinking and take time. In particular, they are strongly interconnected with other important issues of relevance, such as energy policy at the planetary scale and economic, financial, social and geopolitical considerations that are in constant evolution.

 

5.              It is sensible to ask for a scientific summary of the IPCC work, not addressing policy makers but as objective as possible a summary of the present status of our knowledge and ignorance about climate science. Such a report must refrain from ignoring basic scientific practices, as the SPM authors blatantly do when claiming to be able to quantify with high precision their confidence in the impact of anthropogenic C02 emissions on global warming. Statistical uncertainties, inasmuch as they are normally distributed, can be quantified with precision and it can make sense to distinguish between a 90{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} and a 95{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} probability, for example in calculating the probability of getting more than ten aces when throwing a die more than 10 times. In most physical problems, however, and particularly in climate science, statistical uncertainties are largely irrelevant. What matters are systematic uncertainties that result in a large part from our lack of understanding of the mechanisms at play, and also in part from the lack of relevant data. In quantifying such ignorance the way they have done it, the SPM authors have lost credibility with many scientists. Such behaviour is unacceptable. A proper scientific summary must rephrase the main SPM conclusions in a way that describes properly the factors that contribute to the uncertainties attached to such conclusions.

 

6.              The issue of the 15 or so year pause in global temperature has not been properly addressed. Even if it is true that we are experiencing a simple hiatus, that more heat has been stored in the oceans than expected but will some day be released, that on a long time scale this will only be seen as a fluctuation, we have no serious basis for the argument. It is undeniable that the pause has come as a surprise in a context where anthropogenic C02 emissions keep increasing. It has obvious implications on factors that are not properly taken into account in the climate models. As such, it deserves a very critical study aiming at a proper evaluation of the uncertainties attached to predictions. This is what should be expected from a serious scientific approach. An indirect consequence may be that the warming which occurred in the latter part of the twentieth century is only partly the result of anthropogenic C02 emissions. If such were the case, it would affect the models in a way that has not been properly taken into account by the IPCC report. Moreover, the pause indicates that one should take one’s time before deciding on irreversible actions; should keep one’s head cool rather than panicking; and use the time efficiently to improve the models that are not consistent with observations.

 

7.               As a neutral scientist observing the climate debate, I  regret the harm that it does to the image of science with the general public. I recognise the existence of a significant number of competent and knowledgeable climate scientists, who refuse to have their results misused by irrational propaganda. I note that they mostly express themselves with integrity and have to face unacceptable aggressiveness, including insults and ad hominem attacks, by those who consider that they know better than them what the right message should be. While being by conviction a supporter of the precautionary principle and a defender of the preservation of the environment of the planet, I am shocked by the unscientific attitude that prevails in green interpretations of the IPCC work. In such a context, I consider that the IPCC scientists should feel morally compelled to produce a scientific summary of their work while refraining from giving the world a message. They should feel morally compelled to answer the legitimate objections that have been voiced by people such as Professor Curry, in particular in her April 2013 testimony to the US House of Representatives, or Professor Richard Lindzen of MIT4, to quote only two of the most emblematic figures. Specifically, the 2013 Report of the Nongovernmental International Panel on Climate Change: Climate Change Reconsidered II: Physical Science, while intentionally written as a provocation, lists a number of questions, which IPCC should consider it a duty to answer scientifically, without using arguments of authority. The main points of contention might be, for example:-

•              that climate models predict warming that has not occurred at all: atmospheric (>0. 3° over the past 15 years), oceanic (>0.2° since 2000), tropospheric (hot spot) and south-polar in the late twentieth century

•              that they assume a sensitivity of 3° for a doubling of CO, above pre-industrial values while at most 1o is observed

•              that they underestimate by a factor of 3 surface evaporation caused  by increased temperature

•              that they wrongly assume the whole temperature rise since the beginning of the industrial revolution to have resulted from human CO2 emissions

•              that they ignore internal oceanic climate oscillations such as the Atlantic Multi-decadal Oscillation and Pacific Decadal Oscillation (El Nif\o/La Nina)

•              that they ignore the incidence of the solar cycle on the cosmic ray flux and the resulting formation of clouds

•              that they inadequately model cloud formation and aerosol induced changes. Now to answer specifically the questions the Committee:-

How robust are the conclusions in the AR5 Physical Science Basis report?

Have the IPCC adequately addressed criticisms of previous reports? How much scope is there to question of the report’s conclusions?

The AR5 report reviews a large amount of valuable work, including a significant part of which has been produced after the publication of the 2007 AR4 report. Its conclusions, as expressed in the Summary for Policy Makers (SPM), -are far from robust; address only partly criticisms of previous reports; and give a distorted view of the full report itself.

 

To what extent does AR5 reflect the range of views among climate scientists? While it is easy to find a vast majority of scientists who consider that evaluating the potential danger of an excessive (whatever it means) emission of C02 is of utmost importance, they will usually recognize that our current knowledge prevents making reliable predictions and they will not see it as urgent to take decisions. 

 

However, in most cases, on the basis of their relying on the precautionary principle, they would mostly be for considering seriously ways to limit in the long term, our C02 emissions. They will agree that no decision should be taken under pressure, but should take due consideration for economic, financial, social and geopolitical considerations for which they do not claim particular competence (other than as ordinary citizens).

 

Can any of the areas of the science now be considered settled as a result of AR5’s publication, if so which? What areas need further effort to reduce the levels of uncertainty? A scientist will never claim that issues are definitely settled. However, it seems that issues concerning the dynamics of oceans and the complex roles of clouds are in the forefront of matters that need to be researched.

 

Understanding better the north-south asymmetry or the so-called hot spot seem also issues requiring much immediate attention. Not being a climate scientist, however, I cannot give much weight to my assessment of the situation in this respect.

 

 How effective is AR5 and the summary for polfcymakers in conveying what is meant by uncertainty in scientific terms? Would a focus on risk rather than uncertainty be useful? The way the SPM deals with uncertainties (e.g. claiming something is 95{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} certain) is shocking and deeply unscientific. For a scientist, this simple fact is sufficient to throw discredit on the whole summary. The SPM gives the wrong idea that one can quantify precisely our confidence in the model predictions, which is far from being the case.

 

Does the AR5 address the reliability of climate models? Even if it does it in several places in the report, it lacks too often the critical attitude that should be expected, sometimes eluding rather than facing embarrassing questions. The SPM does not address in a proper way the issue of the reliability of the climate models.

 

Has AR5 sufficiently explained the reasons behind the widely reported hiatus in the global surface temperature record? Of course not, how could it? One can only suggest hypotheses. The coming decade should help us with understanding much better what is most relevant.

 

Do the AR5 Physical Science Basis report’s conclusions strengthen or weaken the economic case for action to prevent dangerous climate change?

 

In the short term, it weakens the case for taking urgent action. In the long term, it supports the importance of taking global warming as an important factor in decisions affecting the. future of the planet, together with energy policy, management of natural resources, social, financial, economic and geopolitical considerations.

 

What implications do the IPCC’s conclusions in the AR5 Physical Science Basis report have for policy making both nationally and internationally? I  am not competent to answer this question (other than repeating what I  have already said).

 

Is the IPCC process an effective mechanism for assessing scientific knowledge? Or has it focussed on providing a justification for political commitment? The mission given to the IPCC of addressing policy makers rather than scientists has contributed to the deterioration of the quality of the climate debate up to a point that may well now be no return. One may claim today that it was predictable, but I do not think that one could have predicted that it could reach such a depressingly aggressive and irrational level.

 

To what extent did political intervention influence the final conclusions of the AR5 Physical Science Basis summary? I have no competence to comment on this point.

 

Is the rate at which the UK Government intends to cut C02 emissions appropriate in light of the findings of the IPCC AR5 Physical Science Basis report? I have no competence to comment on this point.

 

What relevance do the IPCC’s conclusions have in respect of the review of the fourth Carbon Budget? I  have no competence to comment on that point.

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Professor Pierre Darriulat, a physicist who served as Director of Research at CERN , has an illustrious scientific career and has lecture in prestigious universities, such as Harvard and Cambridge.

The above is a summary of Professor Darriulat’s submission (December, 2013) to the UK Parliament’s Energy and Climate Change Committee’s inquiry about the latest conclusions of the IPCC’s Fifth Assessment Review (AR5)