Abstract:

The Working Group III contribution to the Sixth Assessment Report of IPCC emphasizes climate change mitigation. The Chapter Transport has provided an overview-based feasibility assessment of the measures to mitigate transport-related greenhouse gases (GHG) emissions. The transport sector had been growing since 1990 and became the fourth largest source in 2019, only after electricity, industry, and the agriculture, forest and land use (AFOLU) sectors. The report focuses on reduction in traffic demand, decarbonization options for land-based transport, shipping and aviation, aiming to reduce transport-related GHG in developed countries and control its growth in developing countries. The different fuel and power technologies evaluated are at different levels of commercialization, with different application timings and scales in the future. Based on the multi-level perspective (MLP), the strategy of demand reduction and efficiency improvement is at the Meso-regime level and has not yet become mainstream. The strategy of land transportation electrification is shifting from the Meso-regime level to the Marco-landscape level. Alternative fuels for marine and aviation are only at the Micro-niche level, requiring deployment targets, regulatory changes, research and development programs and demonstration trials. For the first time, the IPCC separates the shipping and aviation sectors to discuss their GHG emissions trends and the decarbonization opportunities and challenges they face. In the medium to long term, all sectors need to emphasize the management of demand for transport services and the improvement of transport efficiency. Scenario literature suggests that global warming targets require economy-wide emission reduction measures, and the mitigation potential of transport electrification in particular depends heavily on the decarbonization of the power sector. Compared to 2010, transport-related emissions could increase by 65% in 2050 without mitigation measures while could reduce by 68% if the mitigation strategy is successfully deployed, which is also in line with the 1.5℃temperature rise target. These mitigation measures are of great significance for transportation in China to achieve emission peak and carbon neutrality.

Key words: IPCC AR6, Greenhouse gases (GHG), Mitigation measures, Demand side, Electric mobility, Alternative fuels