Thursday, February 24, 2011

Should targets be targets?

The Cancun agreements set a precedent by recognising the need to limit average temperature change to 2oC above pre-industrial levels in order to avoid dangerous climate change. The agreement also “recognises the need to consider... strengthening the long-term global goal on the basis of the best available scientific knowledge, including to a global average temperature rise of 1.5oC.” In light of this, we met in our first discussion group to examine the trajectories of these two temperature targets, and the effectiveness of temperature targets as compared to emotional negotiating for reducing greenhouse gas emissions.

Both the 2oC and 1.5oC targets have long histories within the United Nations Framework Convention on Climate Change (UNFCCC) process. The UNFCCC has aimed to prevent ‘dangerous climate change’ for a long time. The Second Assessment Report of the IPCC identified potentially serious changes resulting from an average increase in global temperatures of 2 degrees. From then on, dangerous climate change was associated with 2oC of warming. There are several reasons to question the assimilation of dangerous climate change with 2oC of warming, or in fact any specific temperature increases (for more see here, here and here). Firstly, a rise of 2oC would pose a threat to many people and places: dangerous depends a lot on the scale, or resolution (e.g. at the household or global scale?) at which one is willing to consider these effects. There is no individual number that could denote at what point changing temperatures become dangerous; 2oC and dangerous are arbitrary stipulations.

Finally, on a more theoretical level, there is in fact an epistemological – that is, in our way of knowing the world – flaw in the logic of assigning a limit to temperature increases (see this interesting article). Although there have been great gains in Global Climate Models (GCMs) which can predict climate change, its effects and its causes, the world is still a surprising place (or in scientific terms, the world is uncertain). These GCMs only denote probabilities of limiting increasing temperatures given certain concentrations: we can never know for sure what will happen at a given concentration. More importantly, given feedbacks that exist in biophysical systems – such as melting tundra and sea ice – there is no way of knowing that we are capable of sticking to a target anyway: targets and timetables are inherently uncertain. Assigning a temperature target and expecting to get there requires being able to predict the future; perhaps putting our faith in these targets and their models is also dangerous?

Nonetheless, as an alternative to the 2oC target, the 1.5oC target was proposed by the AOSIS coalition during the Copenhagen COP. In particular, the small island state of Tuvalu spearheaded a proposal to make the Copenhagen agreements legally binding, and to restrict warming to 1.5oC. Other atoll countries, such as the Republic of Kiribati and the Maldives agreed to abandon their commitment to the 1.5oC proposal in exchange for climate change adaptation funding from the Government of Australia. Tuvalu, however, refused to ratify a treaty that did not commit to limiting global temperature increases to 1.5oC and organised a ‘walk-out’ from the negotiations. This push from Tuvalu was recognised and support by many; in particular journalists and civil-society-organisations. In Cancun some of this effort was recognised: the Accord noted that a target of 1.5oC should at least be investigated.

In the midst of formal, scientific discussions (including which temperature targets would be more appropriated) the frustrations of the Tuvaluan delegation overflowed. As well as staging a ‘walk-out’ of the negotiations, their frustrations manifested in one of the Tuvaluan negotiators weeping whilst making a statement (for more details see here). This has led some social scientists to question whether emotions might allow for unexpected and reformist opportunities and results in negotiations. The weeping in question briefly destabilised the rationality, formality and scientific focus of the meeting. This analysis raises interesting questions about the role of emotions amongst negotiators. For example: can a negotiator ever be unemotional or disinterested; which emotions are, or should be allowed and who’s; would a female weeping be treated the same as a male?

Importantly, examining emotions shines a critical light on the focus, or even obsession, of temperature targets. Whilst one may doubt the potential success of negotiating through emotions (how do you decide what is a legitimate emotion; would this lead to more or fewer positions or agreement), we also have doubts about temperature targets, some of which were mentioned above.

Temperature targets are also subject to some very basic, practical limitations. Current atmospheric concentrations of CO2 are above 390ppm. A 2oC target broadly suggests the need to stabilise these concentrations at about 450ppm with a peak between 2010 and 2015. Thus, limiting temperature increases to 2oC requires serious action, and soon (some think we have even missed this opportunity).

Yet, all these numbers (concentrations and temperature targets) are only probabilities – ‘best estimates’. In fact, accuracy is lost when temperature targets are converted from greenhouse gas concentrations. GCMs, very basically, work from GHG concentrations to forcing to temperatures (see here). Going backwards through this system, from temperatures to forcing to concentrations is difficult as the boundary conditions, or assumptions, are lost. In other words, trying to specify greenhouse gas concentration targets from temperature targets is a bit like trying to understand the characteristics of a person based on their footprints in the sand. And it is the concentration that causes the temperature increases, and which is therefore important.

But perhaps the temperature target is more of a rhetorical rather than a scientific tool. A temperature target is more visceral than a concentration target; people can relate to and comprehend temperature increases. Furthermore, as targets go, perhaps temperature is not such a bad one: after all, it’s SMART (specific, measureable, achievable, relevant and time based)!

In the end, whatever the best indicator – temperature rise, or atmospheric concentrations, or sea level rise, or people displaced – none of these indicators help to reduce greenhouse gas emissions. A target doesn’t force any or every specific country to commit to greenhouse gas emission reductions: it is currently non-binding. Further, targets encourage quibbling about the exact temperature we are willing to accept, rather than focusing on how we are going to get there. Our basic conclusion is this: 2oC or 1.5oC is an important distinction in outcome; but at the moment it is distracting from what is most important– we need to reduce emissions.


  1. Interesting post. A few comments:

    - The link in "(see this interesting article)" isn't working for me.
    - As a follow up, you might consider the "trillionth tonne" or "350" ppm alternative targets, especially in light of some of your valid criticisms of temperature targets.
    - I'm not sure that I would agree that the label of "dangerous" is arbitrary, so much as it needs to be defined in a non-scientific basis, using agreed upon normative values.

    Looking forward to your future posts!

  2. Interesting stuff - a good first post. I wrote about how the concept of targets goes over a few years ago here

    I don't think I still agree with all of what I wrote, but it's an interesting area for reflection.

    Also looking forward to more posts. Good work.