
Interagency observations and analyses show that emissions of the second-most important ozone-depleting substance are back on the decline after a recent surge.
Atmospheric measurements show that concentrations of ozone-depleting gases are declining in response to global controls on their production and use enacted under the Montreal Protocol of 1987 and its amendments. The decline since the early 1990s in the atmospheric concentration of trichlorofluoromethane (CFC-11), once widely used as a foaming agent and refrigerant, has been an important component of ozone layer...