Ditch the 2℃ warming goal

摘要

For nearly a decade, international diplomacy has focused on stopping global warming at 2℃ above pre-industrial levels. This goal - bold and easy to grasp - has been accepted uncritically and has proved influential. The emissions-mitigation report of the Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC) is framed to address this aim, as is nearly every policy plan to reduce carbon emissions - from California's to that of the European Union (EU). This month, diplomatic talks will resume to prepare an agreement ahead of a major climate summit in Paris in 2015; again, a 2℃ warming limit is the focus.