Rethinking mitigation of air pollutants by burning nature gas in northern China

Abstract:

Natural gas (NG) is regarded as clean energy, provoking an aggressive coal replacing project by NG to relieve air pollution in northern China since 2018. As an extreme case, NG consumption in Qingdao (a coastal mega city) doubles in 2018 and 2019 than in 2017 in accompany with 2-5% decreases in coal and 1% increase in oil. Here, we used the long-term mass concentrations of air pollutants to estimate their deweathered percentage decreases (DPDs) in Qingdao during heating seasons since 2013, e.g., the season in 2013 started from November 2013 to March 2014. A surprisingly large rebound of CO in DPD, as high as ~20%, occurred in 2018 against 2017 after ~20% DPDs achieved in 2016-2017. ~10% rebound of NO₂ and PM_2.5 in DPDs also occurred in 2018 against in 2017 after 20-40% DPDs achieved since 2014, and the rebound were temporally terminated by COVID-19 pandemic. The largely increased NG combustion deteriorated air quality, which needs urgent investigation.