An image provided by NOAA shows the hole in the ozone layer in 2015. NOAA scientists now say emissions of one ozone-depleting chemical appear to be rising, even though the chemical has been banned and reported production has essentially been at zero for years.
NOAA via AP
Nitrogen oxide pollution in India and China is offsetting U.S. gains in cutting emissions, researchers say. This photo from October shows road traffic, along with smoke and smog, in front of the landmark India Gate in New Delhi.
Environmental Protection Agency Administrator Gina McCarthy testifies at an oversight hearing of the Senate Environment and Public Works Committee on Capitol Hill in Washington on July 23.
J. Scott Applewhite/AP