Energy Policy, Vol.38, No.6, 2964-2975, 2010
Keeping warming within the 2 degrees C limit after Copenhagen
The object of the United Nations Climate Change Conference in Copenhagen in December 2009 was to reach an agreement on a new international legal architecture for addressing anthropogenic climate change post-2012. It failed in this endeavour, producing a political agreement in the form of the Copenhagen Accord. The Accord sets an ambitious goal of holding the increase in the global average surface temperature to below 2 degrees C. This paper describes 45 COP-only mitigation scenarios that provide an indication of what would need to be done to stay within the 2 degrees C limit if the international climate negotiations stay on their current path. The results suggest that if developed countries adopt a combined target for 2020 of <= 20% below 1990 levels, global CO2 emissions would probably have to be reduced by >= 5%/yr, and possibly >= 10%/yr. post-2030 (after a decade transitional period) in order to keep warming to 2 degrees C. If aggressive abatement commitments for 2020 are not forthcoming from all the major emitting countries, the likelihood of warming being kept within the 2 degrees C limit is diminutive. (C) 2010 Elsevier Ltd. All rights reserved.