A risk hedging strategy for the 2°C target and the Copenhagen Accord

This report presents the results from a research project ”Long term impact of the Copenhagen accord regarding the 2 degree target”, done at VTT Technical Research Centre of Finland during autumn 2010 and winter 2011 for the Nordic Ad Hoc Group on Global Climate Negotiations (NOAK). The report portrays greenhouse gas emission pathways that would minimize the costs of reaching the 2oC target, while simultaneously taking into account the uncertainty of and future learning on climate sensitivity. Using these scenarios, we argue that the emission level resulting from the Copenhagen Accord would be at least 5 Gt CO2 eq higher than the cost-effective level in 2020. Therefore future climate negotiations should aim for more ambitious emission reductions, both in and after 2020.