Environment

Growing Use of Chemical Harming Ozone Layer

Emissions of a neglected class of ozone-destroying chemicals not controlled by a U.N. treaty to protect the ozone layer are on the rise, according to new warnings from researchers.

While the “very short-lived substances” (VSLS) have only a brief influence on stratospheric ozone, their soaring emissions are causing concern.

In particular, emissions of dichloromethane, a manmade VSLS used in industry, can cause ozone depletion that is almost four times more efficient at influencing climate than longer-lived gases such as CFCs (chlorofluorocarbons).

Computer models suggest, compared with the better-known CFCs, dichloromethane emissions reduce the ozone layer by less than 1 percent.

But Leeds University researcher Ryan Hossaini says: “At some locations, its atmospheric concentration has doubled since the late 1990s.”