Opportunities to Advance Mitigation Ambition in China: Non-CO2 Greenhouse Gas Emissions
Non–carbon dioxide (CO2) greenhouse gas (GHG) emissions are a substantial driver of climate change and have significant negative impacts on air quality, human health, and food production. In 2014, the last year with official data, non-GHG emissions in China were greater than total GHG emissions in Japan or Brazil.
China’s policy development since 2015 has led to a significantly lower non-CO2 GHG emissions trajectory than expected under policies as of 2015. This paper estimates that non-CO2 GHG emissions will grow modestly until 2030 under current policies, remain flat between 2030 and 2040, and then begin a more significant decline.
There is significant potential to further reduce non- CO2 GHG emissions beyond the effects of current policies. With additional actions, China could further mitigate 1.5–3.0 billion tons of carbon dioxide equivalent (Gt CO2e) cumulative emissions between 2020 and 2030. The country’s non-CO2 emissions can stabilize as early as 2020 at a level lower than expected under the current policies trajectory.
Key mitigation prospects include reducing hydrofluorocarbons, methane emissions from coal mines, as well as nitrous oxide from nitric and adipic acid production.
China does not have a quantitative top-line target for non-CO2 GHGs in its nationally determined contribution (NDC). The country should enhance its NDC in 2020 by establishing ambitious and precise targets for non-CO2 GHG reduction and implement actions correspondingly. The country should also identify additional ways to further reduce non-CO2 emissions by 2025.
- Under the Reference Scenario, China’s non-CO2 GHG emissions would grow significantly. Between 2012 and 2030, emissions would increase by around 44 percent, and would continue to grow another 15 percent between 2030 and 2050. Most emissions emanate from industrial processes, given that use of HFCs increases as hydrochlorofluorocarbon (HCFC) consumption and production phases out. Emissions from nitric and adipic acid production are also a significant factor.
- Since 2015 policy development has fundamentally changed the trend of non-CO2 GHG emissions in China. Under the Current Policies Scenario, while emissions will grow modestly between 2020 and 2030, they will remain flat between 2030 and 2040 before a more evident decline after 2040.
- Other actions would further reduce non-CO2 GHG emissions significantly below the trajectories expected under current policies. With strengthened action, China’s non-CO emissions could stabilize as early as 2020, a decade earlier and at a lower level than under the current policies trajectory. Annual non-CO2 GHG emissions could return to the 2012 level as early as 2030.
- Strengthened action would significantly lower cumulative emissions. While current policies will reduce 3.5 Gt CO2e cumulative emissions by 2030 and 17.8 Gt CO2e cumulative emissions by 2050 compared to the Reference Scenario, strengthened actions will further reduce 1.5–3.0 Gt CO2e cumulative emissions by 2030 and 7.9–17.5 Gt CO2e cumulative emissions by 2050.
- China is able to mitigate around 280 Mt CO2e per year from non-CO2 GHGs by 2030 at low cost. With more ambitious yet attainable action, the impact will be almost doubled. Reduction could be achieved from the top seven emission sources, which represent more than 76 percent of non-CO2e emissions in 2030. Figure ES-3 demonstrates the range of mitigation potential for each emission source.
Full executive summary in the paper.