The IPCC and the Conservatism of Consensus

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By Ian Angus

Climate change deniers frequently argue that the Intergovernmental Panel on Climate Change represents extreme voices with a vested interested in overstating the problem of global warming. A recent National Post editorial said the IPCC is “as alarmist as any scientific committee could be.” (March 22) This week, another editorial in the same paper referred to “the United Nations’ sensation-mongering panels on climate change.” (April 3)

Even writers who are more sympathetic to the IPCC often assume that the forecasts offered in the Summary for Policy Makers in February by IPCC Working Group I (SPM-1) are outside limits — that the Panel’s high end estimates of temperature increase and sea level rise are worst case scenarios, that “realistic” estimates are much lower.

They couldn’t be more wrong. The IPCC is a conservative body, and the Summary is a conservative document that doesn’t come close to describing how serious global warming might be.

The issue of rising ocean levels, discussed here earlier (Part One, Part Two) illustrates the point clearly. A table in SPM-1 shows a minimum rise of 18 centimetres, and a maximum of 59 centimetres by the end of this century. That table has been widely cited as showing the best and worst cases.

In fact, elsewhere in the report the IPCC notes that the actual worst case figure might be 10 or 20 centimetres more, and that “larger values cannot be excluded.”

That takes the maximum to 79 centimetres or more — but even that is not the outside limit. Before the SPM-1 was released, meteorologist Bob Correll, chair of the Arctic Climate Impact Assessment said that any prediction of less than a metre would “not be a fair reflection of what we know.” One of the world’s most respected climatologists, James Hansen of the NASA Goddard Institute for Space Studies, wrote last week that

“it is impossible to accurately predict sea level change on a specific date … [but] as a physicist I find it almost inconceivable that BAU [Business As Usual] climate change would not yield a sea level change measured in meters on the century time scale.” (“Scientific reticence and sea level rise”)

Unlike the National Post’s editors, many writers who actually know something about science believe that the IPCC has understated the problem.

  • New Scientist, Feb. 9, 2007: “the IPCC’s review process was so rigorous that research deemed controversial, not fully quantified or not yet incorporated into climate models was excluded. The benefit — that there is now little room left for sceptics — comes at what many see as a dangerous cost: many legitimate findings have been frozen out.”
  • Scientific American, April 2007: “By excluding statements that provoked disagreement and adhering strictly to data published in peer-reviewed journals, the IPCC has generated a conservative document that may underestimate the changes that will result from a warming world, much as its 2001 report did.”

Is the IPCC Corrupt?

Some green activists attribute the IPCC’s conservatism to political interference in the scientific process. David Wasdell, Director of the Meridian Programme at the UK-based Unit for Research into Changing Institutions, argued this position in a report published two weeks after SPM-1 was released.

In “Political Corruption of the IPCC Report?” Wasdell carefully compares the published Working Group I Summary for Policymakers to a previous draft. He argues that the final editing process watered down the draft. In particular, “any reference to possible acceleration of climate change [was] consistently removed.” He identifies 11 areas in which the published SPM-1 is less clear, less forceful, and less specific about the dangers of climate change.

Wasdell says that after the IPCC’s previous report was published in 2001, “the fossil-fuel industry recognised that the scientific information presented by the IPCC posed a massive threat to its future profitability and steps were taken to gain control of its process and agenda.” The Bush administration proceeded to replace two prominent U.S. representatives on the IPCC and “several other leading authors and review editors” with people who were “acceptable to the Washington Administration.”

As a result, the final version of SPM-1 was “consensually agreed line by line by governmental agents.” They produced a document that was “immediately welcomed and affirmed as acceptable to the Washington Administration.”

“The outcome is a document which lays a necessary but far from sufficient basis for the formulation of strategic policy. Despite the best efforts of the global scientific community, pursuit of goals based upon this Report may contribute to the sustained profitability of the hydro-carbon-based industries, but they do not get to first base in the task of preventing catastrophic climate change.”

Not Convincing

Anyone familiar with Washington’s well-documented history of political interference in climate science will realize that Wasdell’s charges are credible. There is no doubt that Bush gang prefers to downplay (or deny) the problem of greenhouse gas emissions and it is very likely that they tried to influence the IPCC process in a conservative direction.

But credibility isn’t enough – it’s necessary to prove the case, and Wasdell hasn’t done that. His argument that the changes made between a draft and the final version result from political corruption is unconvincing.

In the first place, the document is a summary of a much longer report – so the real question is whether the summary represented the conclusions of that report more or less accurately than the draft. Wasdell doesn’t discuss that.

More seriously, his evidence for “political corruption” amounts to no more than the far-from-surprising fact that the Republican administration replaced Democratic appointees with its own when it took office in 2001.

Many scientists agree that SPM-1 is too conservative, but the charge that the process was “corrupted” by U.S. political interference has won no support from anyone who is actually knowledgeable about the process.

Twenty Coordinating Lead Authors of the Summary, scientists from eight countries, have replied to Wasdell’s charges, saying that he “appears to be ill-informed about the processes involved in drafting this report.”

“Any draft versions of the chapters or the Summary for Policymakers (SPM) were just that, documents in which inconsistencies were rectified, gaps were closed, and complicated matters were explained more clearly and in more accessible terms….“[Wasdell mistakenly claims] that the Summary for Policymakers was written by and for the government delegations and changes were made to the scientific conclusions before and during the Paris plenary for political purposes. In fact, the Summary for Policymakers was written by the scientists who also wrote the underlying chapters….

“Those of us also involved in previous assessments were pleasantly surprised that there were far fewer alterations made to the text at this final meeting, and that there were very few attempts at political interference.”

The Lead Authors don’t say what those “very few attempts” were, but a published account of the debates preceding publication says that, “fears that the US delegation might try to veto the scientists’ findings proved unfounded.” Rather, the Chinese delegates proved to be the most determined advocates of softening the draft, and only one of their proposed changes was approved –

“after a 10-hour debate on the relative influences of solar and human activity, an exasperated meeting agreed to remove a sentence saying that the change in radiative forcing – the heat entering the system – that is attributable to human activities was ‘likely’ to have been at least five times greater than that due to changes in solar activity. The Chinese argued that the influence of the sun could be greater.”

If that’s the extent of political corruption of SPM-1, we don’t have much to worry about!

Scientific Reticence

An alternative and more plausible explanation has been advanced for the IPCC’s conservatism that has important implications for future research efforts. Climatologist James Hansen of the NASA Goddard Institute for Space Studies suggests the IPCC’s tendency to understate the extent and danger of global warming flows from the nature of the scientific method..

“I suggest that ‘scientific reticence’, in some cases, hinders communication with the public about dangers of global warming. If I am right, it is important that policy-makers recognize the potential influence of this phenomenon.“Scientific reticence may be a consequence of the scientific method. Success in science depends on objective scepticism. Caution, if not reticence, has its merits. However, in a case such as ice sheet instability and sea level rise, there is a danger in excessive caution. We may rue reticence, if it serves to lock in future disasters. …”(“Scientific reticence and sea level rise”)

Stefan Rahmstorf of Germany’s Potsdam Institute for Climate Impact Research and a member of the German delegation to the IPCC, reinforces Hansen’s insight:

“I fully agree with what he writes about “scientific reticence.” His words echo my own experience very well. In many IPCC discussions I have noticed a strange asymmetry: people were very concerned about possibly erring on the high side (e.g., the upper bound of sea level rise possibly being criticised as “alarmist”), and not very concerned about erring on the low side (or some even regarding this as a virtue of being “cautious”). …

“Giving a low value is considered “safe”, it requires no courage for sticking your neck out, while giving a high number is considered risky and alarmist. I don’t think we are doing our job properly if we apply double standards to “low” and “high” estimates in this way. We need to dispassionately look at all the evidence, regardless of what is politically convenient or risky.” (RealClimate, March 28, 2007)

Conservative Consensus

Reluctance to declare big conclusions until every doubt is eliminated is a normal part of scientific investigation, and it undoubtedly plays a role in “moderating” the IPCC’s reports. But there is more going on in this case: the IPCC process itself, the rules of the game, reinforce and amplify scientific reticence.

It’s important to understand that the IPCC itself does not “do science.” Its mandate is to assess and report on the current state of scientific knowledge about climate change. In “taking decisions, and approving, adopting and accepting reports,” the IPCC itself, and all of its working groups, are required to “use all best endeavours to reach consensus.” (“Principles Governing IPCC Work”)

Back in the 1960s, I had the frustrating experience of participating in meetings and conferences of the Canadian wing of Friends of SNCC. (SNCC – the Student Non-Violent Coordinating Committee – was then the most radical wing of the Civil Rights Movement in the southern United States.) For reasons that were never explained to me, the group operated by consensus – every decision had to be unanimous. The potential for a hostile individual or group to block all decisions was obvious, but because the participants actually wanted Friends of SNCC to succeed, anyone making a motion or proposal tried to frame it in a way that would be supported by everyone present. If that effort failed, long and tedious discussions usually produced the desired result – a lowest-common-denominator decision that everyone accepted.

The IPCC’s rules allow for the publication of dissenting views when consensus cannot be reached – but the Summary for Policy Makers includes no such dissents. Clearly the commitment to consensus was very strong and very effective.

The fact that consensus on such a complex subject was reached relatively easily shows that the authors of the initial drafts did just what members of Friends of SNCC did in Toronto decades ago. They limited themselves to matters on which there would likely be unanimous agreement among thousands of scientists from 113 countries, including the most conservative individuals and delegations. And they succeeded.

None of this should be taken as criticism of the IPCC. It has a specific job to do, and it has done it remarkably well. In Hansen’s words:

“IPCC reports may contain a reticence in the sense of being extremely careful about making attributions. This characteristic is appropriately recognized as an asset that makes IPCC conclusions authoritative and widely accepted. It is probably a necessary characteristic, given that the IPCC document is produced as a consensus among most nations in the world and represents the views of thousands of scientists.” (“Scientific reticence and sea level rise”)

A Parable

A repairman told a customer that his brakes urgently needed work, but the man didn’t want to spend the money.“Sir,” said the repairman, “if you don’t get these brakes fixed now, you may be in a fatal accident some time soon.”“But am I certain to be killed?” the car owner asked.“Obviously I can’t say that, but it could happen.”

“Well I’m not going to throw away good money fixing those brakes if there’s any chance at all that I might survive.”

Everyone would agree that the car-owner is acting irrationally: the possibility of brake failure is enough to justify the repair. But the response of many capitalist politicians and propagandist to the IPCC reports has been equally irrational. The outcomes forecast by the Panel are only “likely” or “very likely” – that means they aren’t certain, so there is no need to act now.

What’s worse, they use the IPCC’s “very likely” conclusions as a weapon to discredit conclusions that are less certain but still possible. The National Post, for example:

“Mr. Gore claims sea levels will rise by as much as six metres in the coming decades due to planetary meltdown, when, in fact, even the United Nations’ global warming committee … predicts the rise will be no more than 40 centimetres.” (March 22, 2007)

In reality, if global warming continues unchecked, it’s 100% certain that the Greenland and Antarctic ice will melt and the oceans will rise even more than six metres. The only uncertainty is how quickly it might happen.

The IPCC’s very high standard for including scientific results makes it a highly credible scientific resource. But that same high standard weakens it as a guide for policy and action. If there is any chance that my brakes might fail, I want to know so that I can get them fixed. Similarly, just the possibility that inaction will produce an ecological catastrophe in this century is grounds for immediate radical change – and the people of the world need to know that so they can act.

But it will take a different kind of organization than the IPCC to spread that news.

Scientists and Marxists

Despite its conservativism, Working Group I’s Summary for Policy Makers has radical implications. Although it repeatedly hedges its statements with cautionary words such as “likely” and “probable,” SPM-1 clearly states that global warming is real, that it is primarily caused by human-produced greenhouse gases. Those vital points directly challenge the Business-As-Usual climate agenda of the Bush administration and its allies in Canada, Australia and elsewhere, so the suggestion that it was corrupted to promote the oil industry’s priorities makes little sense.

This doesn’t mean that capitalist governments, including the Bush gang, didn’t want to or didn’t try to influence the process. It simply means that so far as outside observers can tell, the scientists involved – including the U.S. delegates – worked honestly and with a high degree of integrity to produce a document that accurately reflects the consensus of scientific opinion today.

But precisely because it is a consensus document, it does not include outcomes and trends that some climate scientists view as “possible,” but on which there is not yet widespread agreement.

In particular, SPM-1 (presumably following the still-unpublished report it summarizes) generally assumes that climate change will occur in a straightforward linear fashion. It does not incorporate recent research that suggests the possibility of “abrupt” or “non-linear” changes that could rapidly accelerate global warming or even produce unstoppable runaway increases in greenhouse gas emissions and icecap melting.

As Marxists, we’re not surprised to see scientific results that predict sudden transformations where “quantity turns into quality,” and we may even be predisposed to think such dialectical outcomes are probable. But it isn’t appropriate for us as Marxists (except for any of us who are also climate scientists) to take sides in scientific debates – or to prefer some particular scientific opinion because it appears to correspond with our political/philosophical outlook. The ecosocialist movement must be informed by the best current scientific knowledge, but being socialists doesn’t qualify us to judge the probable accuracy of a specific scientific forecast.

The IPCC’s reports contain a wealth of data and analysis that every ecosocialist should be familiar with and publicize. But we shouldn’t limit ourselves to the IPCC consensus. It’s very important to break through the myth that the IPCC reports include the worst-case scenario. We must constantly stress that the IPCC’s projections are conservative, that far worse outcomes are possible.

To do this, we should publicize the work of scientists whose work is not yet part of the consensus, but which provides more insight into the range of possible outcomes of global warming.

And we should support and encourage those scientists to make their views and conclusions part of the public policy debate. James Hansen is one scientist who is attempting to do this:

“The broader picture gives strong indication that ice sheets will, and are already beginning to, respond in a nonlinear fashion to global warming. There is enough information now, in my opinion, to make it a near certainty that IPCC BAU climate forcing scenarios would lead to disastrous multi-meter sea level rise on the century time scale.“There is, in my opinion, a huge gap between what is understood about human-made global warming and its consequences, and what is known by the people who most need to know, the public and policy makers. IPCC is doing a commendable job, but we need something more. Given the reticence that IPCC necessarily exhibits, there need to be supplementary mechanisms. The onus, it seems to me, falls on us scientists as a community.” (“Scientific reticence and sea level rise”)

Hansen has proposed that the U.S. National Academy of Sciences report “publicly, and in plain language” on “the threat to the great ice sheets posed by human-made climate change.” Such a report would be a powerful tool for green and socialist activists, and we should support his proposal.

The IPCC is what it is. It isn’t an activist organization, and it doesn’t include the full range of climate change possibilities in its reports. It produces summaries of the scientific consensus about global warming – and it is a profound commentary on how badly capitalism has damaged our world that the IPCC’s conservative statements of fact constitute a powerful indictment of the capitalist system.

For that reason alone, ecosocialists should publicize its work as widely as possible – and make up for its shortcomings through our own efforts.

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