The analysis of current national emissions targets from the Copenhagen Accord has found that the present pledges are likely to lead to a world with global emissions of 47.9 gigatonnes to 53.6 gigatonnes of carbon dioxide equivalents (GtCO2-eq) per year by 2020. This is like racing towards a cliff and hoping to brake just before the edge. The current pledges mean a greater than 50% chance that warming will exceed 3oC by 2100. Even if emissions are halved by mid-century, this will still leave the planet with, at best, a flip-of-the-coin chance of meeting the 2°C goal. The analysis found that the only way to achieve the 2oC limit, or even the 1.5oC which more than 100 nations demand, is to increase the level of emission reductions before and by 2020 as well as to set long-term targets that are in line with achieving these goals.
Article: Rogelj, J. et al. (2010). Copenhagen Accord pledges are paltry. Nature 464, 1126–1128, DOI: 10.1038/4641126a