Why COP 28 is destined to disappoint

From Climate Scepticism

BY JOHN RIDGWAY

Following the spectacle and theatre of COP 28, I thought it might be a good idea to remind ourselves of the rationale behind the targets upon which its deliberations were founded. After all, we all thought we knew that a two degree Celsius increase in temperature would spell disaster. Now we all presume to know that one and a half degrees will do the trick. But what exactly is the strength of the science behind the determination of such thresholds?

The COP 28 delegates will tell you that they don’t care anymore, because this is a matter of settled science, and that is all you need to know. Short shrift would be given to any suggestion that there is still debate to be had concerning the scientific basis. As for any suggestion that the specification of the targets was actually a political manoeuvre … well, that is to laugh. Except it’s true, and I’m not even joking.

That values ascribed to safety targets owe more to politics than science should not strike you as controversial, but I am prepared to bet that it will, at least where climate change safety targets are concerned. This is because, whereas safety professionals are quite aware of the arbitrariness that often accompanies the quantification of targets, climate policy-makers wouldn’t dream of conceding an inch on the mantra of ‘following the science’. For them, two degrees increase doesn’t just provide a simply understood framework within which to work, it represents a consensus arrived at by thousands of scientists objectively beavering away in the way that scientists always do. It’s as if the 40 mph speed limit that suddenly appeared on your commute to work was the result of endless studies of accident statistics, combined with consideration of the local road conditions as related to accident causation, rather than an arbitrary gesture in response to a general road safety campaign (which is actually the much more likely scenario). I’m sure a set of consultants would have been employed to validate the choice of speed limit, but rest assured that their recommendations were provided only to help push through the ‘correct’ policy. Speaking as a former traffic control systems safety analyst, I have to hope that you can just take my word that this is how these things generally go down.

But climate science is different, I hear you say. Well, let us look at the evidence for that. What exactly is the history behind the setting of the current climate change speed limit?

It’s politics, stupid

It is generally accepted that the first person to mention a two degree Celsius limit was Nobel economist William Nordhaus, back in the 1970s. As he put it:

“As a first approximation, it seems reasonable to argue that the climatic effects of carbon dioxide should be kept within the normal range of long-term climatic variation. According to most sources the range of variation between distinct climatic regimes is in the order of ±5°C, and at the present time the global climate is at the high end of this range. If there were global temperatures more than 2° or 3° above the current average temperature, this would take the climate outside of the range of observations which have been made over the last several hundred thousand years.”

The first thing to note here is the range of uncertainty, i.e. ‘2° or 3°’. The second is how weak the argument is for this ‘first approximation’. It doesn’t involve a detailed scientific assessment of the impacts of warming, it merely makes the ‘reasonable’ assumption that we might not wish to invite an unfamiliar scenario. As such, it is essentially precautionary in its nature. Furthermore, no data or citations were offered at the time by Nordhaus to back up his claims regarding the Earth’s temperature record.

Be that as it may, there were many who were later willing to back Nordhaus’s intuitions. In particular, the WMO/ICSU/UNEP Advisory Group on Greenhouse Gases produced a report in 1990 that re-iterated the significance of a 2° limit (the lower of the two figures proposed by Nordhaus), this time by arguing for the likelihood of non-linear, catastrophic impacts beyond that threshold. The baton was also picked up by the German Advisory Council for Global Change (WBGU) in the 1990s. It was the WBGU, under chairman Hans Joachim Schellnhuber, that convinced Angela Merkel of the 2°C target, thereby starting a political process that ultimately led to the adoption of the 2°C target by organisations such as the G8, the Major Economies Forum, and the Conference of the Parties held in 2010 in Copenhagen. It was also largely through the exhortations of Schellnhuber (a member of the Club of Rome advocating for a ‘move towards more equitable economic, financial, and socio-political models’) that the target was later to be reduced to 1.5°C. Again, such arguments were ostensibly motivated by the desire to avoid tipping points that could not be proven but were deemed sufficiently plausible to invoke the precautionary principle.

I would not wish to give the idea that there was no science behind the proposal of the 2°C target, or indeed its subsequent reduction to 1.5°C. However, it would be naïve to suggest that the values chosen arose from any detailed calculations corroborated by multiple groups of scientists working independently. The history of the limit owes a lot more to the scientific hand-waving of small but influential bodies who have furnished their political overlords with suitably rounded numbers that can function as a focal point in the climate policy arena. In that respect, the analogy with traffic speed limits is most apt. The science might suggest a speed limit of 37 mph, and even that different limits apply for differently experienced drivers. It is fortunate, however, that speed limits are not set by scientists but set by politicians who understand that focal points are important for success, and simplicity is important for focal points. Richard Betts of the Met Office puts it this way:

“The level of danger at any particular speed depends on many factors… It would be too complicated and unworkable to set individual speed limits for individual circumstances taking into account all these factors, so clear and simple general speed limits are set using judgement and experience to try to get an overall balance between advantages and disadvantages of higher speeds for the community of road users as a whole.”

So 40 mph it is for everyone. Similarly, 1.5°C is chosen not so much for its scientific accuracy but for its political expediency. After all, it is supposed to equate to an acceptable level of risk, and questions of acceptability are political rather than scientific.

Build it and they will come

And that would be the end of my story were it not for one more important detail. If 1.5°C is just a number plucked out of the air because it sets a good target, then why is it that so many scientific studies have subsequently appeared to verify its critical importance? How come that a figure that arose from years of intuitions, guesses and vaguely applied scientific insights has proven to be bang on the money, according to the current crop of peer-reviewed articles published in prestigious journals.

To understand this apparent coincidence, one has to appreciate just how a politically established focal point serves to guide the direction taken by scientific study. Furthermore, one has to drop the naïve view, often expressed, that the scientific method and the competitive nature of the scientific enterprise ensure that any suspect propositions will be challenged and ultimately overturned. The main problem with this naïve view is that it ignores the social feedback that occurs once a particular view has gained dominance. In an ideal world, such dominance should not interfere with the objectivity of decisions taken, but in the real world there are positive feedbacks that tend to reinforce popularity at the expense of veracity. Put another way, once an authoritative position has been established, credence can no longer be purely evidence-driven. One example of this phenomenon is the Matthew Effect as it applies to the establishment of a dominance of citations for particular researchers. Unfortunately, however, because science is a social undertaking, such feedbacks are a lot more pervasive than citation bias alone might suggest, since they also bear upon the popularity of research undertaken, methods adopted, the conclusions to be drawn and the chances of gaining publication. None of the above are free decisions to be undertaken, since they will all be marshalled by a guiding social hand that reinforces with agency that has no need of conspiracy.

Occasionally, though rarely, the reality of social feedback within the scientific domain will be highlighted by those who operate within it. The message is rarely welcomed, however, since it undermines the whole idea that scientific authority can always be trusted to inform political decision-making. The suggestion that science has a propensity to provide politically correct answers does not go down well with those who have been brought up to believe in an unchallengeable scientific integrity. And so the social sanctions for those who speak out can be severe, as exemplified by the recent experience of climate scientist Patrick T. Brown when he detailed how these mechanisms operate within climate science. To him there is no surprise that research vindicating the 1.5°C target hugely dominates within the prestigious journals, any more than I wasn’t surprised to see safety analyses that conveniently validated traffic speed limits that had been the result of politically taken decisions.

But does any of it matter?

One of the most interesting features of limits and targets is the alacrity with which they are set and the facility with which they are ignored. There are laws of physics that should be borne in mind when determining whether a proposed action or current situation can be deemed sufficiently safe. But the law that states ‘thou shalt not exceed 1.5°C warming’ is of quite a different stripe. It was readily conceived with the minimum of required science, and has been subsequently ‘validated’ with more science than can be decently applied. Since COP 15, such limits have been treated with a dread reverence that looks increasingly melodramatic when one considers how much reality and rhetoric have diverged. It is no wonder, therefore, that each successive COP declaration has been heralded with unprecedented hope, only to be reviewed with unprecedented despair. I guess there is only so much one can achieve by setting limits when everyone knows that they are just symbolic focal points.