Constructing long-term scenarios for land transport’s greenhouse gas emissions

Abstract

For the first time the impact of transportation’s indirect greenhouse gas emissions, notably of ozone and aerosol precursors, will be quantified in the on-going EU project “Quantify” - along with the direct greenhouse gases, of course. Long-term emission scenarios on all continents are a necessary element for global impact estimates, due to the long atmospheric lifetime of climate relevant species and their global mixing. Here we present a pragmatic approach to construct useful scenarios on the potential development of global land transport’s emissions up to and beyond the year 2050. Beyond the technical difficulties we discuss what criteria there are to judge the plausibility of such developments. Vice versa, what guidance is needed for the interpretation of scenarios?