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.

Keywords: 2 °C target; Air pollutants; Electrification; Energy shift; Removal technologies; SLCPs.