Substantial progress has already been made to curb GHG emissions from fossil-fuel combustion in a number of countries, including large emitters like the People’s Republic of China,1 the European Union or the United States. Current efforts are, however, unlikely to be enough to avoid average temperatures increasing by 4°C above pre-industrial levels by 2100. The IPCC’s latest assessment finds, for example, that scenarios in which the average temperature increases by less than 2°C over the 21st century involve global GHG emission reductions between 40% and 70% by 2050 compared with 2010 levels (IPCC, 2014).