2005-2016 trends of formaldehyde columns over China observed by satellites: increasing anthropogenic emissions of volatile organic compounds and decreasing agricultural fire emissions

We use 2005–2016 observations of formaldehyde (HCHO) columns over China from the OMI,GOME‐2, and SCIAMACHY satellite instruments to evaluate long‐term trends in emission inventories of volatile organic compounds (VOCs) that affect air quality. The observations show large increases over2005–2016 in the North China Plain (+1.1 ± 0.5% a−1relative to 2005) and the Yangtze River Delta region(+1.5 ± 0.4% a−1relative to 2005), consistent with the trend of anthropogenic VOC emissions in theMulti‐resolution Emission Inventory for China (MEIC). Unlike other pollutants, VOC emissions have not been decreasing in recent years. An exception is the Huai River Basin in rural eastern China where the satellite data show rapidly decreasing VOC emissions since the early 2010s that appear to reflect bans on agricultural fires