So far, climate change mitigation pathways focus mostly on CO2 and a limited number of climate targets. Comprehensive studies of emission implications have been hindered by the absence of a flexible method to generate multi-gas emissions pathways, user-definable in shape and the climate target. The presented method ŒEqual Quantile Walk¹ (EQW) is intended to fill this gap, building upon and complementing existing multi-gas emission scenarios. The EQW method generates new mitigation pathways by Œwalking along equal quantile paths¹ of the emission distributions derived from existing multi-gas IPCC baseline and stabilization scenarios. Considered emissions include those of CO2 and all other major radiative forcing agents (greenhouse gases, ozone precursors and sulphur aerosols). Sample EQW pathways are derived for stabilization at 350ppm to 750ppm CO2 concentrations and compared to WRE profiles. Furthermore, the ability of the method to analyze emission implications in a probabilistic multi-gas framework is demonstrated. The risk of overshooting a 2°C climate target is derived by using different sets of EQW radiative forcing peaking pathways.
If the risk shall not be increased above 30%, it seems necessary to peak CO2 equivalence concentrations around 475ppm and return to lower levels after peaking (below 400ppm). EQW emissions pathways can be applied in studies relating to Article 2 of the UNFCCC, for the analysis of climate impacts, adaptation and emission control implications associated with certain climate targets. EQW data and software are available at http://www.simcap.org.

FIACC - Future International Action on Climate Change Network
The purpose of this website is to provide an interactive international platform for discussion on future international action on climate change, including approaches of a post-2012 commitment regime under the UNFCCC and the Kyoto Protocol.

European Commission DG Environment Future Action
Communication and Working papers on future action