The 2 degrees Celsius target

In 1992 the great Rio meeting adopted the United Nations Framework Convention on Climate Change, and ever since, ‘combatting global warming’ and, when warming paused, ‘combatting climate change’ became the name of the game for the Greens, internationalists and the worried. We’ve had conference after conference about how to create a comprehensive global treaty that would see greenhouse gas emissions greatly reduced. It looks to me as far away as ever.

The current hope of the worried  is that this will be done by 2015, and come into force in 2020. I think this is quite unlikely. Since 1992 carbon dioxide accumulations in the atmosphere have increased by a third, while temperature has not risen much at all. Nonetheless, the cry has been to limit the global temperature increase to 2 degrees Celsius, which is thought to prevent our crossing the threshold into dangerous ‘climate change’.

Where did this 2 degree figure come from? It was not formally adopted until 2010 at the Cancun conference, but had been about for years before that. I think the simplest answer is that was agreed by those present at Cancun to be simple, easy to remember and apparently possible. A German policy analyst, Oliver Geden, has now written a long and interesting paper to brush the 2 degrees figure aside, arguing that ‘this goal is patently unrealistic. And since a target that is obviously unattainable cannot fulfill either a positive symbolic function or a productive governance function, the primary target of international climate policy will have to be modified’.

Geden says that instead of wasting our time worrying about how not to cross the threshold we should think about how to modify it. Doing so pragmatically carries risks, especially for the EU, which pushed the 2 degrees target for years before it was adopted. But there is no Plan B, he says. And policymakers can’t just say ‘Oh well…’, because the target is thought to be based on the  (settled) science. Given the pause, and the continued accumulation of carbon dioxide, a crunch is coming, and quickly.

The truth is that the 2 degrees target was political, not scientific. ‘Members of the climate policy community often emphasize that the 2°C target is a figure derived from scientific research. Scientists themselves, however, are generally well aware that this target is more political in nature—another target could have been set just as easily.’ Geden’s essay reminded me that the IPCC reports have never adopted the 2 degrees target, though he expects that the Fifth Report, out in a few days, will discuss it.

The problem with the target is that the EU and some other countries have built it into their energy policies, and the target embodies therefore what are in anyone’s terms drastic cuts in emissions, which are not sustainable in terms of the countries’ own economies. This is Geden’s position too. So what is his proposed Plan B?

Well, the EU could seek to modify the target date (2015), or do without such a date. Or it could go hard for ‘negative emissions’ — much faster reforestation and biomass production. Or it could accept that temperatures might overshoot in the short run, if it could be confident that the overshoot were temporary. It could look for a benchmark of some kind instead of a strict upper limit on temperature. Or it could reject the top-down, global, grand solution altogether, and accept that all countries would do the best they could.

The trouble with each of these options is that each of them moves away from the symbolic target of 2 degrees that was simple and urgent. I think he wants to have his cake and eat it too, for he seems to believe, along with the UN Environmental Program  ‘that current climate policy will be able to prevent a marked increase in global emissions, which over the long term will have the effect of raising temperatures on the order of 3.5°C.’ It’s hard to know how long ‘the longer term’ is, so I’ll let that one go through to the keeper.

In passing, he says of the UNEP’s Emission Gap Report, that  it ‘is written largely by distinguished scientists and in past issues has contained both dismal climate change scenarios and optimistic policy forecasts, a combination that is typical of the climate discourse in general’. I liked that one.

Where does all that get us, here in Australia? His conclusion is that the target has to change, and when it does, the role of ‘climate science’ will change also, if only because the 2 degrees target is supposed to be based on the best scientific advice. Two comments of his are directly relevant to us.

‘The impending necessity to reinterpret or even revise the 2°C target primarily marks a fundamental failure of international climate policy. But it also highlights the failure of scientific policy advice.’

and

‘To remain relevant, scientific policy advisors will have to cease to issue absolute demands as if these were the only alternatives available to policy makers.’

And how far away are we from ‘crossing the threshold’? Heaven knows. If the current pause continues, a very long time.