A pause in progress on air pollution

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Science  18 May 2018:
Vol. 360, Issue 6390, pp. 749-750
DOI: 10.1126/science.360.6390.749-f

Air pollution regulations in the United States have led to dramatic improvements in air quality over the past several decades. It therefore is discouraging to learn, as Jiang et al. report, that the reduction of nitrogen oxide and carbon monoxide emissions slowed sharply between 2011 and 2015. This is important because controlling these species is necessary for reducing tropospheric ozone pollution. A variety of factors likely caused this slowing of pollution reduction, including growing industrial contributions and a variety of vehicle-related trends. Improved satellite and model inversion technologies would help monitor changes in pollutant emissions and more precisely identify their sources.

Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1801191115 (2018).

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