a, Emission price trajectories applied to non-CO2 greenhouse gas emissions in the default case and the two sensitivity cases. In line with the scope of emissions covered under the UNFCCC, emissions from aerosol or aerosol precursor species such as black carbon or sulphur dioxide are not explicitly subjected to a carbon price. b–g, Resulting emissions of CO2 and internally consistent evolutions of a selection of non-CO2 emissions. h–j, Effect of non-CO2 sensitivity cases on decadal rate of temperature change in the period 2090–2100. Note that the sensitivity case that assumes zero penalty on non-CO2 emissions is extremely unlikely in light of recent efforts that specifically target reductions in methane and fluorinated gas emissions. Emissions of non-CO2 gases are translated into CO2 equivalence using global warming potentials over a 100-year time horizon as reported in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change74.