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.