A worldwide ban on ozone-depleting chemicals in 1987 has averted a climate catastrophe today, scientists say.

The Montreal Protocol on Substances that Deplete the Ozone Layer, banning chemicals such as chlorofluorocarbons, has now simulated our “world avoided”.

Without the treaty, Earth and its flora would have been exposed to far more of the Sun’s ultraviolet (UV) radiation.

Former UN Secretary General Kofi Annan has called it “perhaps the single most successful international agreement”.

Tortured plants

Continued and increased use of chlorofluorocarbons (CFCs) would have contributed to global air temperatures rising by an additional 2.5°C by the end of this century, the international team of scientists found.

Part of that would have been caused directly by CFCs, which are also potent greenhouse gases.

But the damage they cause the ozone layer would also have released additional planet-heating carbon dioxide – currently locked up in vegetation – into the atmosphere.

“In past experiments, people have exposed plants – basically tortured plants – with high levels of UV,” lead researcher Dr Paul Young, of the Lancaster Environment Centre, said.