The ozone layer is on track to recover within decades as harmful chemicals are phased out, scientists report | CNN

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CNN

The rare good news for the planet is that Earth’s ozone layer is on track to fully recover within decades as ozone-depleting chemicals are phased out around the world, according to a new United Nations-backed assessment.

The ozone layer protects the planet from harmful ultraviolet rays. But since the late 1980s, scientists have been sounding the alarm about a hole in this shield caused by substances that deplete the ozone layer, including hydrochlorofluorocarbons, also known as CFCs, commonly found in refrigerators, aerosol cans and solvents.

International cooperation helped limit the damage. The use of CFCs has declined by 99% since the Montreal Protocol came into effect in 1989, which began the phase-out of those and other ozone-damaging chemicals, according to the assessment of a panel of experts published Monday.

If global policies continue, the ozone layer is expected to recover to 1980 levels for most of the world by 2040, the assessment found. For polar regions, the time frame for recovery is longer: 2045 over the North Pole and 2066 over Antarctica.

“Ozone action sets a precedent for climate action. Our success in phasing out ozone-depleting chemicals shows us what can and must be done – urgently – to move away from fossil fuels, reduce greenhouse gas emissions and thus limit the rise in temperature,” said Secretary-General of the World Meteorological Organization Petteri. language axis.

Ozone-depleting gases are also potent greenhouse gases, and without a ban, the world could have experienced an additional warming of up to 1 degree Celsius, according to a 2021 study in the journal Nature. Since the industrial revolution, the planet has already warmed by about 1.2 degrees and scientists have warned that that temperature must be limited to 1.5 degrees to avoid the worst consequences of the climate crisis. A warming of more than 1.5 degrees would dramatically increase the risk of extreme drought, wildfires, floods and food shortages, scientists have reported.

For the first time in this assessment, which is published every four years, scientists also looked at the prospect of solar geoengineering: the attempt to reduce global warming through measures such as spraying aerosols into the stratosphere to absorb sunlight. reflected from the Earth’s atmosphere.

They found that injection with a stratospheric aerosol could help reduce climate warming, but warned there could be unintended consequences. Deployment of the technology “could also impact stratosphere temperature, circulation, and ozone production, destruction, and transport rates,” said the report, which is published every four years.



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