Environmental and economic effects of the Copenhagen pledges and more ambitious emission reduction targets

Global carbon dioxide emissions need to be reduced by at least 50 to 85 % in 2050 com-pared to 2000 levels to limit global surface temperature increase to 2°C compared to pre-industrial levels (IPCC 2007). As an intermediate greenhouse gas emission reduction target for industrialized countries in 2020 the IPCC (2007) confirmed a range of 25 % to 40 % com-pared to 1990, together with a substantial deviation from baseline in some developing re-gions, which was quantified as reductions in the range of 15 % to 30 % below baseline (den Elzen and Höhne 2008). While the climate summit in Copenhagen (COP 15) failed to come up with an international agreement involving binding greenhouse gas emissions reduction targets, under the Copenhagen Accord (UNFCCC 2009) most Annex I countries pledged quantifiable emission reductions. Similarly, several developing countries submitted nationally appropriate mitigation actions (NAMAs).