IPCC Fifth Assessment Report

Alan Whitehead Excerpts

Thursday 20th November 2014 Westminster Hall

[Mr Lilley]

Yes. I normally call myself a lukewarmist. I believe that the climate will warm a bit, which will probably be quite beneficial to parts of our country, although it could pose problems elsewhere. I do not deny that double the amount of CO₂ in the atmosphere will increase the temperature by 1° and a bit, plus or minus any effect due to positive or negative feedbacks. However, I do not think that the evidence shows that the change will be very large. I will come to that.

It is not just climate sceptics and I who have been critical of the IPCC’s tendency to exaggerate. Following the discovery of inaccuracies, use of grey data and so on in AR4, the fourth assessment report, which forecast that all the glaciers in the Himalayas would melt in 35 years rather than 350 years, the InterAcademy Council—the council of all the main scientific academies in the world, including our Royal Society, the US scientific bodies and so on—carried out an investigation of how the IPCC worked. The IAC was critical, particularly of authors who

“reported high confidence in statements for which there is little evidence”.

It is not just fellow sceptics and I saying it; all the scientific academies of the world, which by and large have signed up under some political pressure to rather unscientific statements about global warming, have considered the IPCC report and concluded that some scientists, although not all, tend to report high confidence in statements for which there is little evidence. The IAC therefore recommends:

“Quantitative probabilities (as in the likelihood scale) should be used to describe the probability of well-defined outcomes only when there is sufficient evidence. Authors should indicate the basis for assigning a probability to an outcome or event (e.g., based on measurement, expert judgment, and/or model runs).”

No such basis for assigning enhanced probability was given when the most recent IPCC report came out. Its headline conclusion was that the evidence for human influence has grown since the fourth assessment report, and it went on to attach increased likelihood—categorised on the scale as “extremely likely”, rather than the previous “very likely”—to the possibility that human influence has been the dominant cause of the warming observed since the mid-20th century. That was the overall headline assessment to which the IPCC wanted policy makers to respond. However, it is hard to back up that conclusion from the substance of that report. Since the last report, we know what has happened.

[Dr Alan Whitehead (Southampton, Test) (Lab)]

Will the right hon. Gentleman give way?

[Mr Lilley]

I will make this point, and then I will give way.

Since the last report, the earth’s surface temperature has not warmed further; indeed, it has not warmed during the entire period of the IPCC’s existence, since 1997 or 1998. There has been a hiatus in warming, yet during that period since 1997, one third of all the carbon dioxide ever emitted by mankind has been pumped into the atmosphere. We have had 17 years to test the effect of a third of all the CO₂ we have ever emitted, and there has been no increase in temperature. That does not mean that the global warming thesis is dead or wrong—I believe in it—but it does mean that it is not the dominant factor. It means that during that period, other factors were masking any warming due to the increase in CO₂.

[Dr Whitehead]

I would like to get something clear. Is the right hon. Gentleman suggesting that the issue relates to the difference between “extremely likely” in the fifth assessment report and “very likely” in the fourth assessment report? That is, does he stand by the idea that anthropogenic global warming is very likely, although he might not stand by the idea that it is extremely likely, or is he saying that it was not very likely in the first place?

[Mr Lilley]

I am saying that in its use of those terms, the summary for policy makers has not responded to the recommendations of the InterAcademy Council report.

[Dr Whitehead]

But does the right hon. Gentleman stand by “very likely”?

[Mr Lilley]

I never made that statement. I think that it is uncertain how much of the heating that has occurred since 1950 is due to CO₂. Some of it is; perhaps half of it. I do not know.

It is the word “dominant” of which I am most critical, and the idea that human influence is the dominant factor. During that period, the whole lifetime of the IPCC, there has been no warming, yet a third of the CO₂ ever emitted by man has been put into the atmosphere. That does not seem to be evidence for being more certain; it seems to be evidence for being a little more qualified in stating that CO₂ may be the dominant factor. It clearly was not dominant during that period. By definition, a period with record emissions but no warming cannot provide further evidence that emissions are the dominant cause of warming.

A number of other, quite important factors have simply been omitted from the summary for policy makers. Although the IPCC says that there is increased certainty, it does not tell us, except obliquely in a footnote, that for the first time, the authors of the IPCC report are unable to agree on a best estimate of how sensitive the climate is to increases in CO₂. In previous reports, they have always been able to agree a best estimate, but this time, there has been so much disagreement among them that they have been unable to reach one. When I was a Secretary of State being advised by experts, if there was disagreement among them, I wanted to know about it; I did not want it hidden from me. If the disagreement was new and had not been present in their previous advice, I doubly wanted to know about it. However, that was not mentioned in the summary for policy makers, which is not a good way to ensure that policy makers are well-informed.

Nor does the summary mention that in the body of the report, the IPCC’s medium-term forecast for temperature increases to 2035 is below that given by the climate models. In other words, the experts used their judgment to say that in their opinion, the climate models are wrong. They came up with a forecast below the models, and they explain that the reason is that the models have been overheating. Their forecasts have not conformed to the facts. I would have liked to have that pointed out to me in the summary for policy makers, but it was not. I would also have liked some explanation why, after 2035, the IPCC assumes that the models will be right and will no longer overheat. If they have overheated in the past and are expected to overheat until 2035, why are they expected to be right thereafter?

The overheating is serious, and it is not just during the period of the hiatus. Over the past 35 years, the models studied by the IPCC have collectively run an average of 15% too high. They are significantly in error. That, too, is something that I would have liked pointed out in the summary for policy makers, so that one would know, when talking about model estimates, that they have been consistently and significantly wrong for 35 years. But that was not pointed out.

According to one of our witnesses, the most significant fact in the whole AR5 was the new evidence about the impact of aerosols. We now have evidence from satellite observations that provides more certain estimates of the prevalence of aerosols in the atmosphere and their impact and suggests that they produce less cooling than was previously assumed. However, there was not time to use that information to rerun the model—sometimes the models take months to run—so none of the models takes into account the latest information on aerosols. Had they done so, they would have produced an even higher forecast for future warming, because the future warming forecast involves the warming created by CO₂ less the cooling created by aerosols. If there is less cooling by aerosols, the forecasts would be higher—that is, more wrong—in the past, and probably even more wrong in future.

Indeed, given that we know what the actual amount of warming has been, if that warming—0.8° C since the industrial revolution—is the result of carbon dioxide, the model suggests that if it had been down to CO₂ alone, the warming would have been something like 1.2%. However, because of the old estimates of aerosols, an offset of 0.4% is assumed, which is why we observe the 0.8° C figure. We know the 0.8 figure is true. If we now have better estimates, so that instead of 0.4% the offset is 0.2%, that means that the CO₂ effect should have been forecast as being 1° C rather than 1.2° C or 1.4° C. That is a significant change—new evidence—that should have been brought to the attention of policy makers but was not.

Nor was the fact that most recent empirically based studies of the sensitivity of the climate to CO₂ have come out with lower figures. Indeed, since the report came out, a study of all the estimates of the sensitivity of climate over time has been made—in the form of a chart—and it shows that the estimates are progressively coming down. In other words, the likely feedbacks must be less and less, as estimates become more accurate and indeed the period with no warming extends. Again, I would have liked to know that in the SPM, rather than it being hidden away in a 1,000-page report, which by definition the policy makers are not expected to read.

We know that there has been a pause in global warming since 1997. My hon. Friend the Member for South Suffolk says that is somehow a statistical fabrication. If I want to know how long this table is, having climbed up the steps to get to it, when I get to the level bit, I measure that to see how long the table is; I do not include the rise before and I do not exclude some of the flat bit. The length of a plateau is the length of a plateau, and it is 17 years. That is quite simple.

If over that 17 years, the effect of CO₂ has been offset by other natural factors—I am not denying the effect of CO₂; I am saying it must have been offset by other factors. [Interruption.] Presumably, the hon. Member for Southampton, Test (Dr Whitehead) agrees with me; if he would like to intervene to disagree, he is welcome to.

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[Dr Whitehead]

indicated dissent.

[Mr Lilley]

No. He agrees with me.

[Dr Whitehead]

I merely pointed out—unfortunately, from a sedentary position—that it is a little dangerous to start talking about plateaux in the context of what has been probably several hundred years of anthropogenic effects. Indeed, at any particular stage, it would have been possible during that period to select particular years to make particular points. However, that is not the greater point that needs to be taken into account; that is about looking at the overall effects over a period. The right hon. Gentleman persists in talking about plateaux when, in overall terms, that is what happens on occasions in a much longer period, and it can be easily demonstrated over the period.

[Mr Lilley]

I entirely agree with the hon. Gentleman. There are periods when temperature has been rising and periods when it has been falling, for example from about 1945 to the early 1970s. Then there was a period of about 25 years when it was rising and everyone said, “That 25 years is very good evidence.” They did not say, “25 years is far too short a period.” They said, “Oh, that’s it. That’s going to go on.” The Met Office gave us forecasts for a single decade of how much things were going to change; it was confident that this was a continually rising trend.

However, there is a period when it has been flat. But if the underlying greenhouse effect has been rising, that means that natural factors are of the same magnitude, and those natural factors—over the long term—will cancel out other factors. Therefore, the upswing in natural factors may have been contributing to the warming in the 25 years of warming, and that should have been brought to the attention of policy makers but was not.

The hon. Gentleman says that I go on about flat periods. However, far worse than the SPM is the press release issued by the IPCC itself, which says:

“Warming in the climate system is unequivocal and since 1950 many changes have been observed throughout the climate system that are unprecedented over decades to millennia.”

It goes on to say that the period of

“the last three decades has been successively warmer at the Earth’s surface.”

So it is talking about warming.

The fact is that the warming since 1950 has not been unprecedented; it is almost exactly the same, over exactly the same period, as the warming that occurred from the end of the first world war up to the second world war. How can we explain the fact that there was a similar amount of warming when there was very little emission of CO₂ to a period with an identical amount of warming when there was a lot of CO₂? It must mean that other factors are relevant, and those other factors are of the same order of magnitude in their impact on the climate as CO₂.

All I am saying is that these things should be drawn to the attention of policy makers. Policy makers should not be treated as children; they should not be fed a line; they should not be given a document that purports to be a scientific document, but is actually an act of advocacy, achieving its end by selective use of facts and omission of a lot of the evidence that the experts who produced it took a great deal of time and a thousand pages to assemble. Sadly, that is why the report from our Committee sounded more like cheerleading than holding to account a body that must be held to the highest standards, and not excused if it happens to agree with our own opinions.

[Dr Alan Whitehead (Southampton, Test) (Lab)]

Mr Betts, I also have to apologise to you for my late arrival this afternoon, and in particular for my inability to hear the contribution to the debate of the Chair of our Select Committee. Nevertheless I predict, although not with absolute certainty, with a fairly high level of certainty that I will probably agree with him in what I say.

I was detained in coming to this important debate by a discussion I was having on Japanese knotweed; to be precise, it was a discussion on Radio 2. On arriving here, I was thinking that perhaps Japanese knotweed is not such an awful metaphor for our debate today, inasmuch as it is here, there is a considerable amount of disagreement about its effect and there is a lot of scientific activity going on at the moment to try to clarify and qualify that effect, including studies to see what insects predate on Japanese knotweed. And there is some uncertainty about whether the effects of insects on Japanese knotweed are real, and about whether “urgent” action needs to be taken, or just “reasonably urgent” action, or “not very much action at all”. So there is quite a lot of debate about Japanese knotweed.

However, what we do know, with a reasonably high degree of certainty, is that Japanese knotweed is very invasive; it uproots our houses and properties, and needs to be dealt with. Indeed, if a surveyor came along to me if I was attempting to deal with my house repairs and said, “It’s very likely that Japanese knotweed is undermining the foundations of your house,” I probably would not say, “I’m not going to do anything about this, because I want to wait until I know that it’s extremely likely that it is undermining the foundations of my house. So I will just let the stuff get on with it until I am absolutely certain, on scientific grounds, that it is extremely likely that my house will be done over.” Instead, I would probably say, “Well, ‘very likely’ is pretty much good enough for me. I’m going to do something about this, and get my house sorted out.”

That in particular was why I intervened on the right hon. Member for Hitchin and Harpenden (Mr Lilley) during his contribution, which was about the difference between the fourth assessment report and the fifth assessment report on the degree of likelihood. While it is true that there has been a change between those two reports in what the guide for policy makers is indicating in terms of just how great a degree of emergency we face as far as the effects of anthropogenic global warming are concerned, the assessment has indeed moved from “very likely” to “extremely likely”. As I have underlined, even if someone did not really think that “extremely likely” was absolutely the starting point for taking any further action, they might be rather alarmed by what has happened previously.

What I then worry about is those people who look at the IPCC’s fifth assessment report, just as the Select Committee has done, and who start to raise concerns about it in the way that we have heard today. It is not that those concerns are illegitimate or necessarily entirely out of court, in terms of discussion. However, after that we have to say, “What might some of those concerns amount to, depending on how they are depicted, as important or otherwise, to what is—as IPCC’s fifth assessment report is—a transition of a series of scientific documents, discussions and conclusions, into a document that has some relevance as far as policy makers are concerned?” Indeed, that is precisely the equivalent of a discussion on the science of Japanese knotweed and the surveyor’s report.

[Graham Stringer]

Does my hon. Friend agree that it would be better if scientists summarised the science, not politicians?

[Dr Whitehead]

It is better that a report produced for policy purposes is a synthesis of what scientists and others are saying and concluding. Indeed, that is exactly what our report concluded.

Beyond that, we then come not to the question of what concerns there might be about some of the detail of the fifth assessment report and its policy summary, but to one important element of scientific method. I should say that I am a social scientist, not a scientist scientist, but I certainly would always have regard to scientific method in my researches and thoughts on a matter, and would be pretty much guided by scientific method and principles of probability and various other things such as those. The important element is that there are always outliers in any scientific discussion. How could it be otherwise? That is what science is about. Science is never unanimous. Indeed, the whole of scientific method is to take something that looks unanimous and test it to destruction and see whether a new consensus emerges from that—and that in turn is tested. There are always outliers and always people who are testing science, and always people who will disagree with a conclusion.

In terms of what science does in informing policy makers, the question is how to best get to the best science that there is, currently, to inform something that will not have 100% certainty behind it but which is, as I have described in terms of what people do about their house, an imperative that they may have to act on, without 100% certainty, but with a high degree of probability behind their actions. That is essentially what the IPCC fifth assessment report is about.

[Mr Lilley]

I intervene to offer the hon. Gentleman some advice on surveyors. If a surveyor is asked to do a report, the probability is that he will find some damp, some rot and something to do, because that is his job; he is a professional alarmist. I have a surveyor coming in a week’s time and I am paying him a fee just for the survey, so that he has not got an incentive to create work. In a sense, the IPCC is a bit like that. It is in the job of producing things that show that CO₂ is an alarming proposition.

[Dr Whitehead]

The right hon. Gentleman is exactly right, but I think that perhaps he slightly misunderstood the process that follows that. If people get a surveyor in, it is quite possible that they will find some things wrong with their house. The probability, in terms of that surveyor’s professional background, is that even if the surveyor finds a few things wrong with their house that they do not think are particularly wrong, he is probably right. The question is to what extent they take action following what the surveyor says. The right hon. Gentleman appears to suggest—I would not put words into his mouth—that people can safely say, “This surveyor is just after his own interests in surveying my house, so I can confidently put this in the bin and purchase the house down the road that the surveyor told me is a complete turkey, safe in the knowledge that he is trying to make money. Therefore I can completely disregard what he said. And then, when my house falls down, I will be sorry about it, but I am safe in the knowledge that I wasn’t taken in by that beastly surveyor, who was trying to make some money.” I am not sure that the argument really follows in its fullness. I want to concentrate on that for a few moments in respect of the IPCC report.

One concern about picking small holes in a report and bringing outliers on board in emphasising the size of those holes is that, eventually, people might say, “Perhaps those holes need to be looked at”—indeed, the Committee in its report identified a number of areas in the procedures of the fifth assessment report and the summary following it that did need looking at and action for the future—and they fairly soon elide into talking about conspiracy theories and asking, why would people have falsified data and put things into this report? Or why would scientists from across the world have congregated together to overthrow their own scientific method and start putting bogus material into reports and trying to smuggle such material into summary reports, to falsify those and affect the gravity of action that may be required for policy makers?

The problem then arises of people moving away from citing holes and difficulties to saying that the whole thing is therefore a bunch of falsified bunkum. I have to say that hon. Members contributing to this debate in a contrary position from that of the fifth assessment report and the Committee’s conclusions seem to be sailing rather close to the wind on that. As soon as people get into the area of conspiracy theories, that is the complete overthrow of science. Conspiracy theories and science are mutually self-destructive.

We have to accept, surely, that this IPCC fifth assessment report was carried out by honest scientists from around the world, who honestly put forward what they did because they had found it to be so in their view, and that the collocation of those various views—a difficult process in its own right—was also undertaken by honest people coming to particular conclusions. Unless we think otherwise, we will eventually be in the position of saying, as I have mentioned, not necessarily that it is extremely likely that anthropogenic action on the climate is the cause of global warming, but that it could be “Very likely”, “Maybe”, “Extremely likely”, “Maybe not”, “A bit between the two”, or “Very likely that it is very likely”, and then we are in no man’s land. At that point, people may start saying, “If they are all fabricating these things and the evidence really is a tissue of misrepresentation and lies, then we have no guide at all for policy in future,” which is, after all, what we ought to be discussing in this Chamber.

[Mr Lilley]

Normally, the hon. Gentleman is good, in that he follows the logic of my questions through, sometimes to points that I did not want him to reach, but here he is putting words into my mouth that are the exact opposite of what I said. I did not say anyone had falsified anything; I simply said they had excluded material that was in the main report from the summary for policy makers. I hope he will clarify that. I was not accusing anyone of inventing falsehoods.

[Dr Whitehead]

The right hon. Gentleman is right. He will recall that I said that it sounded to me a little bit like that was the direction in which some of the contributions might be moving. I do not personally accuse the right hon. Gentleman of taking that position. However, a number of other people—not he—have taken and do take that position and it seems to me that they are, as a result, hopelessly adrift in terms of what we might or might not do.

[Graham Stringer]

I hope that my hon. Friend does not mean me. I hope I made it quite clear that, as far as I am concerned, the scientific papers are produced—unless evidence shows they are not—by scientists of integrity. Where the problem lies is that representatives of Governments take a large amount of that science and reach political compromises, which is bad for the production of a document. That should be done by scientists, because they would produce a different document. Because they represent the view of their Government, Government representatives stop information from those scientific papers getting into the report. That is not a conspiracy; that is political process.

[Dr Whitehead]

My hon. Friend sets out a process that seems remarkably similar to every single bit of policy work that ever takes place anywhere in the world on pretty much anything. There is a scientific process and if scientists wish to inform policy makers who are involved in that process, those policy makers will be involved in a process that is less than perfect in relation to what the science says. It is a combination of what is possible, what the policy is that is informed by the scientific process and, most importantly, whether the policy makers should wait for the science to be absolutely perfect before they do anything. My hon. Friend is coming close to saying that unless the science is perfect and scientists can have a sign-off on absolutely everything that goes on to the desk of the last policy maker, we should do nothing.

[Ian Lavery]

I am probably the only person here who is not a scientist. Politicians who, like me, are not scientists rely on evidence from scientists on both sides of the argument, because we, as politicians, make decisions based on what the scientists tell us. Where does that leave me?

[Dr Whitehead]

My hon. Friend is in exactly the position that I have just described. He is a policy maker who has to be advised by the best science. Given the full and informed contributions that he has always made to our Select Committee considerations, he is the complete embodiment of that process. Policy makers have to combine how they see the landscape with what the science is advising about the landscape and make judgments about what should be done in relation to those two facts in their role as policy makers. That is not and should not be a surprise to anybody. There is a real link between what the science is telling us and what we as policy makers have to do about it.

[Graham Stringer]

My hon. Friend is being generous with his time. The British Government do not follow the same process as the IPCC when it comes to scientific advice. The Government have a scientific adviser who gives independent advice to the Cabinet and the Prime Minister. Each Department has a scientific adviser and specialist committees. They do not wait until there is certainty; they produce the best available science at the time and Ministers take decisions on that advice. If the IPCC followed that process, I would be a much happier person, but it does not do that. It introduces politicians into the scientific process. That is where it goes wrong, and that is not describing a conspiracy.

[Dr Whitehead]

My hon. Friend describes the sort of process at an international level that to some extent goes on in Her Majesty’s Government. The document that he refers to, which was referred to by the right hon. Member for Hitchin and Harpenden, is headed, guide for policy makers. It does not purport to be the scientific document. The scientific documents, as we have agreed, are elsewhere.

[Mr Lilley]

It is a “Summary for Policymakers”.

[Dr Whitehead]

It is a summary and a guide for policy makers. If the right hon. Gentleman looks at the document, he will see that that is exactly what it says in those documents. That is how it was announced and how it was reported to the United Nations. Indeed, it is how the United Nations Secretary-General described it. It was specifically set out on the back of the various documents and the detailed material that it was a further document over and above that work, forming a bridge between the scientific material and the guide for policy makers, and that is exactly how it should be seen.

As far as I am concerned as a policy maker, the fact that the IPCC report concluded that the anthropogenic effect on global warming is either “very likely” or “extremely likely” impels me to act, for all the reasons I have described. The Select Committee report was attempting to ascertain the overall veracity of what the IPCC’s fifth assessment report was about, how it translated into policy, possible difficulties and what needs to be done next. That is essentially what our report talks about, and that is good enough for me.

We need to take decisions on how we deal with the decarbonisation of our energy and on limiting as radically as possible the emissions that will add to anthropogenic global warming. Those are the direct policy implications that this House needs to look at closely, and we will unpack that further to say, “We may have disagreements about exactly how we limit the decarbonisation of our energy supply and the many different ways of doing it, but we will have a separate policy makers’ debate”—as my hon. Friend the Member for Wansbeck (Ian Lavery) has alluded to—“on the best method of doing that.” Unless we have an overarching guide where we are clear about what we are doing, most of the rest of that conversation will not make a great deal of sense.

The best endeavours of pretty much all the scientists involved in this area around the world are to get to grips with finding out what is happening, why it is happening and what we should do about it, and we in this Chamber should commend that work and not seek to draw false conclusions from it or pick holes in it that are of no relevance to the overall policy making thrust. I commend what our report says to Government. I hope that they will be able to take on board what is said and ensure that they use it to guide their policy formation, whatever vicissitudes there may be about exactly how we will get there.

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[Dr Whitehead]

It was announced as that.

[Amber Rudd]

Whether in the title of the document or not, it is taken as a guide.