Though the press may have framed the Copenhagen climate conference as an unbridled failure which mainly involved delegates being turned away because the conference centre was not large enough to hold them and tedious politicking, the fifteenth Conference of Parties did come to an agreement. You may be worried that no-one is going to sign it on time, or that it lacked substance or indeed any binding commitments at all, but I think it’s worse than that: I think that the negotiating process was undertaken entirely backwards.

The accord drafted at Copenhagen is notably devoid of any numerical emissions targets. This is not just a terrible disappointment for those hoping for action on climate change—it’s also totally irrational.

So what went wrong? Well, first they assigned a target for global average temperature:

We agree that deep cuts in global emissions are required according to science, and as documented by the IPCC Fourth Assessment Report with a view to reduce global emissions so as to hold the increase in global temperature below 2 degrees Celsius, and take action to meet this objective consistent with science and on the basis of equity.

If you made it past the weaselly (and, frankly, barely grammatical) wording without cringing too hard, you’ll see that they’ve deferred to the IPCC recommendation of keeping global mean temperatures no more than 2ºC above pre-industrial levels—we’ll talk about why this might be a good idea in a moment. The totally irrational bit is that the accord doesn’t then skip ahead to the next stage and actually assign a level of global emissions cuts to make sure we hit this target.

This is stupid, because it’s the ‘easy’ part: turning atmospheric greenhouse gas concentrations into a temperature rise is based on cold, hard science. We can’t make predictions with 100% certainty as the climate system is just too complex, but there’s no economics, sociology or psychology to worry about, and so this is the simplest part of the process. If you make a value judgement that 2ºC is where you want to be, climate science can tell you the probability of getting there for a given emissions scenario. Indeed, to stand anything like a decent chance of achieving this aim, it looks like we need to enact those ‘deep cuts in global emissions’ right now—or, to put it a slightly different way, making damned sure that we never burn the trillionth tonne of carbon.

However, this strange emissions omission underlines a much deeper irrationality in the conduct of the recent international climate negotiations. A reduction in greenhouse gas emissions is not ‘required according to science’. Science, in this context, exists to provide the very best possible evidence for the results of a given emissions scenario, whereas the mitigation of and adaptation to climate change are ‘required’ by our morality.

The moral way to respond to climate change is to make our best scientific and ethical assessment of the amount of death and suffering a given level of climate change will cause, the best scientific and policy estimate of what restricting climate change to that level would cost, and to spend the amount which would save and improve the most lives without taking money away from more economic life-saving initiatives. This is also my reading of the ethical rationale behind carbon pricing.

So what is the difference between 1.7 and 1.8 degrees of warming? Letting things slip to 1.8 degrees would save us a packet, but also damage or end a certain number of lives. The strange fact is that no-one has done a full, sliding cost–benefit analysis of tackling global warming to various degrees. However, it’s only with some estimates of these quantities that we can make a value judgement about what to do—and, unless you’ve got a moral objection to evidence, you’ll need some regardless of the specifics of those values.

There are undoubtedly difficult ethical questions at stake in devising policy to tackle climate change: Is a future life worth as much as one today? What is the optimum population of the Earth? What fraction of its cumulative historical emissions should the developed world take responsibility for, given that our current wealth was bought with them?

It strikes me that the best way to answer these questions is in a vacuum, and, having decided what is ‘consistent with science and on the basis of equity’, dole out emissions quotas guided by these principles. The optimal way to do this would be if we could somehow abstract the decision-making from individual nations’ negotiators. For example, you could randomise where the parties ended up—if they didn’t know whether they’d end up in the US or Burkina Faso, it would be in their interest to negotiate the fairest deal possible such that you didn’t get screwed wherever you found yourself. Unfortunately, this is clearly impractical.

Equally clear, however, is that getting the countries of the World around a table and asking them to voluntarily proffer generous emissions cuts will result in an accord rather like the one produced in Copenhagen.

I would dearly love to see a slew of rational, ethics- and evidence-based studies on acceptable future emissions scenarios, followed by a choice of moral framework leading to a universal commitment by nations to take one of the studied paths. The question is how to square this with the petty, noisy, global prisoners’ dilemma of political reality. Suggestions welcome.

andrewsteele.co.uk