Full-volatility emission framework corrects missing and underestimated secondary organic aerosol sources

Organic aerosol (OA) is the largest and most complicated component of aerosols that greatly affect human health and global climate. However, widely used models cannot reproduce primary and secondary OA concentrations, and thus the source contributions of OA remain elusive. This is largely caused by the oversimplification of traditional organic emission inventories. Here, we develop an emission framework that achieves a full volatility coverage in both the gas and particle phases with a high chemical and volatility resolution. The new inventory fills a gap of 3,382 kt/y semi-and intermediate-volatility organic emissions and 59% ambient secondary OA (SOA) concentrations in China 2017, resulting in a significantly improved model-measurement agreement. Volatile chemical products, domestic combustion, and biomass open burning, with their SOA contributions increased by a factor of two to nine, turn out to be three leading sources of SOA. Future control policies must focus more on these previously underestimated sources.