Ozone hole gradually closing, UN report says

Metro Manila (CNN Philippines, November 7) — The hole in the Earth's ozone layer -- the layer of the atmosphere which protects life from harmful ultraviolet radiation -- is gradually healing, according to a new United Nations (UN) report.

Updated projections by climate change experts said the Antarctic ozone hole is expected to close, with column ozone values returning to 80s levels by about 2060.

Ozone levels in the Northern Hemisphere will also return to 80s values by 2030, while the Southern Hemispheres sees its ozone levels to normalize by 2050.

The ozone holes were first discovered in the 80s, and scientists have pointed to chlorofluorocarbons (CFCs) as the main culprit. In 1987, the UN Environment Programme adopted the Montreal Protocol which bans the use of ozone-depleting substances such as CFCs.

CFCs are found in cooling and refrigeration systems, aerosols. The CFCs destroy the ozone in the atmosphere, allowing UV radiation to get through.

Erik Solheim, head of UN Environment said the Montreal Protocol, is "one of the most successful multilateral agreements in history."

"The careful mix of authoritative science and collaborative action that has defined the Protocol for more than 30 years and was set to heal our ozone layer is precisely why the Kigali Amendment holds such promise for climate action in future," it said.

The Kigali Amendment is set to revise targets under the Montreal Protocol, and will mandate the search for alternatives to hydrofluorocarbons (HFCs). Hydrofluorocarbons (HFCs) present in refrigerants and cooling appliances are a form of greenhouse gas that trap sunlight in the earth's atmosphere.

If this is ratified by 2019, the Earth may avoid a 0.2 to 0.4°C increase. This is in line with the Paris Agreement's plan to limit global temperatures to 1.5°C.