第七届青年地学论坛

Coal-to-clean energy programs (coal bans) can improve air quality and public health and welfare. However, the field measurements taken in rural areas are still insufficient to evaluate the efficacy of coal bans. In this study, more than three years of observations were made on organic carbon (OC), elemental carbon (EC, also called black carbon, BC) and PM_2.5 at a rural site (Xianghe) in the Beijing-Tianjin-Hebei region (BTH) of China in combination with auxiliary measurements in urban areas (Beijing, Tianjin, Langfang, Baoding and Shijiazhuang). As a result of the coal ban, the annual average PM_2.5 concentrations decrease in rural areas. Accordingly, the annual average concentrations of OC declined from 19.1 to 12.3 μg/m³, while those of EC declined from 4.7 to 3.0 μg/m³. The amplitudes of the decrease of total carbon (the sum of OC and EC) and PM_2.5 in the areas of coal ban were greater than those in the non-coal ban areas. Based on the simulation performed using the Weather Research and Forecasting model coupled with chemistry, the quantitative contributions of coal bans and meteorology are discussed. In contrast to those observed in the winter of 2016/2017, the decline in the observed EC concentration could be attributed to meteorological impacts (45%), changes in other emissions (29%) and coal bans (26%) for the winter of 2017/2018 and 15% from meteorological impacts, 40% from changes in other emissions, and 45% from the coal ban for the winter of 2018/2019. For primary OC and PM_2.5 concentrations, fractional changes of 44% and 33% and 67% and 56% could be attributed to reductions in residential emissions (coal ban) for the winters of 2017/2018 and 2018/2019, respectively. In summary, coal bans should be widely implemented in the BTH region of China if the supply of natural gas and electricity is sufficient and local residents can afford clean energy.

OC; BC(EC); the Beijing-Tianjin-Hebei region; Coal-to-clean energy; residential heating