The Ledger · Entry 20
The world nearly eliminated the chemicals that were destroying the ozone layer
World consumption of ozone-depleting substances (ODP tonnes)
Data: Our World in Data, based on the UN Environment Programme Ozone Secretariat
Scientists discovered that common industrial chemicals, chiefly the CFCs in refrigerators, aerosols, and foams, were tearing a hole in the ozone layer that shields life from ultraviolet radiation. In 1987 the world signed the Montreal Protocol and agreed to phase them out.
The key rows
The phase-out worked. Consumption of these substances collapsed by about ninety-nine percent, drawn here on a log scale so the whole fall fits, and the ozone layer is now slowly healing. The last stretch is not zero: small amounts are still used or reported unevenly, and some replacement gases are potent greenhouse gases now being curbed under a later amendment.
Asked often
Did the Montreal Protocol work?
Yes. It is often called the most successful environmental treaty ever. After it was signed in 1987, world consumption of ozone-depleting substances fell from a peak of 1,662,589 ODP tonnes in 1989 to 16,622 in 2021, a fall of about ninety-nine percent.
Is the ozone layer recovering?
Yes, slowly. With the ozone-depleting chemicals almost entirely phased out, scientific assessments project the ozone layer will return to its earlier state over the coming decades. The recovery lags the phase-out because the chemicals already released persist for a long time.
The world also got better today.
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