Ozone layer could recover within four decades, UN-backed report finds

Imagery showing the hole in the ozone layer which is shrinking  (NASA Goddard Space Flight Center)
Imagery showing the hole in the ozone layer which is shrinking (NASA Goddard Space Flight Center)

The ozone layer is set to recover within four decades because of a global phaseout of chemicals, a UN-backed report has found.

A scientific panel said the phaseout of nearly 99% of banned ozone-damaging substances has succeeded in safeguarding the layer.

The Montreal Protocol in 1989 committed countries to banning ozone-damaging chemicals after scientists raised the alarm over a "hole" or decrease in the Earth’s ozone layer which protects humans against harmful ultraviolet rays.

If current policies remain in place, the ozone layer is expected to recover to 1980 levels - before the appearance of the hole - by around 2066 over the Antarctic, by 2045 over the Arctic, and by 2040 for the rest of the world.

The hole has been slowly improving in area and depth since 2000, the report said.

The assessment says that action under the Montreal Protocol is also having a beneficial impact on efforts to curb global warming.

An update to the Montreal Protocol in 2016, known as the Kigali amendment, saw countries agree to phase down the production and consumption of some hydrofluorocarbons or HFCs.

These do not directly deplete ozone but they can have a powerful global warming effect.

The new assessment said the Kigali amendment is estimated to avoid 0.3C to 0.5C of global warming by 2100.

Meg Seki, executive secretary of the United Nations Environment Programme’s ozone secretariat, said: “That ozone recovery is on track according to the latest quadrennial report is fantastic news.

“The impact the Montreal Protocol has had on climate change mitigation cannot be overstressed.

“Over the last 35 years, the protocol has become a true champion for the environment."

World Meteorological Organisation secretary general Professor Petteri Taalas said: “Ozone action sets a precedent for climate action.

“Our success in phasing out ozone-eating chemicals shows us what can and must be done - as a matter of urgency - to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase."