Polycyclic Aromatic Hydrocarbons in China: Will Decoupling of Their Emissions and Socioeconomic Growth Emerge?

Polycyclic aromatic hydrocarbons (PAHs) are emitted into the environment by daily anthropogenic activities and they potentially threaten human health. Over the past 40 years, the coupling between PAHs emissions driven by energy transition and socioeconomic factors has yet to be determined, and future trends between the two parameters are unclear. In China, the emissions of PAHs increased from 1980 to 2016, and the average annual variation rate was 3.5%. After 2016, PAHs emissions were decoupled from socioeconomic growth. PAHs emissions exhibited a change from a developed region (eastern region) to an undeveloped region (central region and western region). The emissions of PAHs, if only driven by energy transition, will reach a peak in 2035 under the shared economic pathways (SSP1, SSP2, SSP4, and SSP5), which are defined to assess sustainable development. The emissions of PAHs will continuously increase by +9.8% under SSP3 during 2020-2050. Comparing these five socioeconomic pathways, SSP1 is the possible choice to achieve the sustainable decoupling of the emissions of PAHs and socioeconomic growth by transforming the drivers of economic growth, thereby optimizing the energy system and cultivating environmentally friendly behaviors.