Time to ditch the 2 degree warming goal?

2 March 2015


Reported by James Hynard, CSaP Researcher

In the first of the Climate and Sustainability in Multiple Dimensions seminar series, an enthusiastic audience gathered to hear Professor Charlie Kennel discuss whether we should ditch the 2 degree warming goal, an issue that he originally raised in a controversial Nature commentary.

Click on the image below to hear the recording of the event.

“Temperature has been a poor measure of climate risk”

Professor Kennel spoke about the unsuitability of the 2 degree warming goal for addressing the challenges of climate change. It is not feasible, it is not meaningful, and it hinders effective political action. Whilst the goal appears attractive and it is technically possible to meet the 2 degree goal, such models require heroic assumptions.

Global temperature increases also fail to accurately indicate the true stress put upon our environment. For example, the recent hiatus in increasing average global temperature hides the fact that the ocean has been absorbing a large amount of energy in that time, with a 30-40% decrease in sea ice over the period of the hiatus. Furthermore, temperature goals do not easily translate into discrete political actions: it is not clear what individual nations must do to achieve only 2 degree warming. As such, the two degree goal hinders effective political action.

“Optimistic views tend to be silent on power and include several ‘musts’: for every ‘must’, there should be a plausible mechanism.”

Professor Susan Owens responded to Charlie’s talk with an analysis of the controversy which his original Nature article provoked. She pointed out that the 2 degree goal was perceived in several different ways which tended to inform people’s reaction; as a long-term scientifically-based goal; as a value-laden goal driven by political reality; and as a hard fought victory which acts as a simple focal point for UN climate negotiations. Susan also reinforced Charlie’s questioning of the feasibility of the target when she noted that optimistic views tended to include the need for extreme actions, without a plausible mechanism for their execution.

Susan finished by listing three false models which she would like to see 'ditched' from public discourse on climate change; the first of political actors as unintelligent and incapable of understanding complexity; the second of technical potential hindered only by social barriers, rather than the more accurate and nuanced reality of joint techno-socio complex development; and finally, the separation of science and politics in the climate change arena. The deep uncertainty, political values, and economic impacts of climate change mean that science and politics are inextricably intertwined.

Upcoming seminars in the series include discussions on the role of finance in tackling climate change, reflections on a recent multi-disciplinary conference in the Vatican, and an exploration of the differing reactions of local communities to climate change. Please see here for more details and to register your attendance.

Banner image from Dave Murphy via Flickr

Professor Charles Kennel

University of California San Diego

Professor Susan Owens

Department of Geography, University of Cambridge