Effect of strengthened standards on Chinese ironmaking and steelmaking emissions

China has produced roughly half of the world's steel in recent years, but the country's iron and steel industry is a major source of air pollutants, especially particulate matter, SO2 and NOx emissions. To reduce such emissions, China imposed new emission standards in 2015 and promoted ultralow emission standards in 2019. Here we use measurements from China's continuous emissions monitoring systems (covering 69-91% of national iron and steel production) to develop hourly, facility-level emissions estimates for China's iron and steel industry. In turn, we use this data to evaluate the emission reductions related to China's increasingly stringent policies. We find steady declines in emission concentrations at iron- and steelmaking plants since the 2015 standards were implemented. From 2014 to 2018, particulate matter and SO2 emissions fell by 47% and 42%, respectively, and NOx increased by 3%, even as the production increased by 14%. Moreover, we estimate that if all facilities achieve the ultralow emission standards, particulate matter, SO2 and NOx emissions will drop by a further 50%, 37% and 58%, respectively. Our results thus reveal the substantial benefits of the Chinese government's interventions to curb emissions from iron and steel production and emphasize the promise of ongoing ultralow emission renovations. The Chinese government's interventions to curb emissions from iron and steel production have not been evaluated. This study develops hourly, facility-level emissions estimates to assess the effects of strengthened emissions standards on pollution from China's iron and steel industry.

Automated summary

The emissions concentrations at iron- and steelmaking plants in China have decreased since the implementation of stricter standards in 2015, with particulate matter and SO2 emissions significantly reduced and NOx emissions slightly increased despite an increase in production. If all facilities meet the ultralow emission standards, emissions of particulate matter, SO2, and NOx are expected to decrease further.