Exploring effective short-lived climate pollutant mitigation scenarios by considering synergies and trade-offs of combinations of air pollutant measures and low carbon measures towards the level of the 2 °C target in Asia

Abstract

This study analyzes emissions pathways and mitigation potentials of greenhouse gases (GHGs), air-pollution and short-lived climate pollutants (SLCPs), while taking mitigation actions for achieving a 2 °C global temperature change limit above pre-industrial levels, so-called “2 °C target.” The study evaluates SLCPs (i.e. BC, CH4, tropospheric O3) mitigation scenarios by considering synergies and tradeoffs of various combinations of low-carbon measures and air pollutants control measures. It was found that, even if CO2 emissions pathways in this study are all similar to achieve the 2 °C target, reaching a carbon price at around 400 US$/tCO2eq. in 2050, SLCPs and air pollutants emissions pathways and mitigation potentials are largely influenced by combinations of some key mitigation measures. The maximum mitigation potential reductions of SLCPs (BC, CH4) and air pollutants (NOx, CO, NMVOC, which are precursors of tropospheric O3) in Asia are 89%, 22%, 67%, 37%, and 11% respectively by 2050 compared to the 2010 levels. After considering both direct SLCP reduction effects (i.e. mitigating BC, CH4) and indirect SLCP reduction effects (i.e. mitigating NOx, CO, NMVOC for reducing tropospheric O3 generation and atmospheric CH4 concentration), it can be adjudged that combinations of widespread promotion of renewable energies, drastic electrification in transport, residential and commercial sectors, high biofuel shares in the transport sector, and a certain level of deployment of removal devices would be effective SLCP mitigation scenarios.