The Guardian view on climate change: good news – but not yet good enough

The Montreal protocol is the most successful environmental treaty in history, and arguably one of the most successful of any international pact.

It phased out the gases that were destroying the ozone layer, averting potential catastrophe and healing the hole that human activities had opened in our protective layer. Unfortunately, it had a side-effect overlooked when it was signed in the 1980s: some of the chemicals substituted for the ozone-destroyers had an effect on the climate thousands of times higher than carbon dioxide. This month, world governments agreed to address that by eliminating the substitute chemicals – called HFCs – potentially reducing rising temperatures by as much as 0.5C in a relatively short time. Scientists put the safe limit on future rises at 2C above pre-industrial levels by the middle of this century: beyond that, catastrophic and irreversible climate changes are judged likely. So the reduction agreed under the Montreal protocol could have an enormous, and swift, impact.

Read The Guardian’s editorial about climate change - “The Guardian view on climate change: good news – but not yet good enough.”