n May 2013 we learned that the daily value of carbon dioxide in the atmosphere had exceeded 400 parts per million (400 ppm). The observation was reported by the monitoring station for atmospheric carbon at Mauna Loa in Hawaii, erected by the American geochemist Charles David Keeling during the International Geophysical Year in 1957-58. The now famous Keeling Curve of rising atmospheric carbon concentrations represents an iconic symbol of anthropogenic climate change as we have been taught to understand it – a global collective action problem caused by excessive greenhouse gas emission to the atmosphere.

What does this finding imply for the politics of climate change? Ever since the international community agreed to prevent ‘dangerous anthropogenic interference with the climate system’ in Rio de Janeiro in 1992 (UN 1992 Article 2), the Keeling Curve has captured the political imagination and represented the benchmark against which responsible climate action is measured and accounted for. Through standardized monitoring and reporting procedures for national sources and sinks of greenhouse gases, states have since the mid-1990s kept track of their national carbon footprints and used them as the basis for allocating targets and timetables for emission reductions. The Kyoto Protocol is a manifestation of this particular political imaginary and represents a distinct era in climate policy-making marked by strong intergovernmental coordination around legally binding rules and standardized carbon accounting procedures developed to ensure international comparability and compliance. The Kyoto era is also signified by the adoption of a global temperature target set at 2 degrees above pre-industrial levels. In its fourth assessment report from 2007, the Intergovernmental Panel on Climate Change (IPCC) indicated that achieving this target will mean stabilizing atmospheric CO2 at maximum 400 ppm (IPCC, 2007).

Against this background, it may appear surprising that the 400 ppm event did not gain more resonance in public discourse. In an effort to raise awareness, the secretary general of the United Nations Framework Convention on Climate Change (UNFCCC) in May this year released a press statement proclaiming that ‘we have crossed an historic threshold and entered a new danger zone (…) In the face of clear and present danger, we need a policy response which truly rises to the challenge’ (UNFCCC 2013). Nonetheless, there are today few who expect the Kyoto blueprint to deliver such a response. The politics of carbon accounting, whether measured in tonnes or in ppm, has failed to incentivize climate action. In the lingering UN climate negotiations, political agreement on new targets and timetables for emission reductions seems more distant than ever, and global carbon emissions are rising rather than decreasing. In 2011 Pricewaterhouse Coopers’ Low Carbon Economy Index reported that the decarbonization rate of the world economy (i.e. carbon dioxide equivalents per units of GDP) also is decreasing. Compared to the 5,1% estimated to be required in order to achieve a 450 ppm stabilization by 2050 (Pielke, 2010), the decarbonization rate in 2011 reached a poor 0,7% (PWC 2012).

Towards a new politics of climate

In the year of 400 ppm, the politics of carbon accounting seem to have reached a dead end. However, rather than interpreting this historical juncture as the failure of climate politics, we may use it to foster more productive political imaginaries. Planetary limits and dangerous natural thresholds may appeal to media and work to mobilize science, but has proved less successful in generating profound political and societal change. More promising are recent efforts to rethink climate change as cultural and social phenomenon. Rather than adopting the powerful symbolism of the Keeling Curve, an increasing number of scholars today insist that climate change is better understood as ‘problem complex’ tied to questions such as development, energy security, water access, environmental solidarity and justice (Jasanoff, 2010; Rayner, 2010; Roman et al. 2012). As we have passed 400 ppm, the study of climate politics is experiencing a promising shift away from an imaginary tied to detached carbon targets, to one which places human experiences, local engagements and a diversity of development priorities at the centre. If we accept that concepts have the power to transform how we think about and ultimately engage with the world, we may expect political practice to follow. 


IPCC 2007 Climate Change 2007 Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (IPCC, Geneva). http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-spm.pdf
Jasanoff S 2010 A new climate for society. Theory, Culture and Society 27(2-3): 233-253.
Pielke R 2010 The Climate Fix: What Scientist and Politicians Won’t Tell You about Global Warming.Philadelphia: Basic Books.
PwC 2012 Too Late for Two Degrees? Low Carbon Economy Index 2012 (PricewaterhouseCoopers LLP)http://www.pwc.com/en_GX/gx/sustainability/publications/low-carbon-economy-index/assets/pwc-low-carbon-economy-index-2012.pdf.
Rayner S 2010 How to eat an elephant: a bottom up approach to climate policy. Climate Policy 10(2): 615-621.
Román M, B-O Linnér, and P Mickwitz 2012 Development policies as a vehicle for addressing climate change. Climate and Development 4(3): 251-260.
UN 1992 United Nations Framework Convention on Climate Change. Available for download at:http://unfccc.int/resource/docs/convkp/conveng.pdf.
UNFCCC 2013 Statement by UNFCCC Executive Secretary on Crossing of 400 ppm CO2 Threshold,Available for download at: http://unfccc.int/press/items/2794.php.

Eva Lövbrand is an Associate Professor in the Department of Thematic Studies (Enviornmental Change) and the Centre for Climate Science and Policy Research at Linköping University, Sweden.

Björn-Ola Linnér is Professor in Environmental Change at the Centre for Climate Science and Policy Research at Linköping University, Sweden, where he was the previous director (2006-2010). He is also associate research fellow at the Institute for Science, Innovation, and Society (InSIS) at Oxford University.