Scientists predict the hole in the ozone layer will close in the next 50 years

Earth’s ozone layer protects all life on Earth from the sun’s harmful radiation.

But in the late 20th century, human emissions of certain damaging chemicals began to affect the number of ozone molecules in the atmosphere. This has resulted in a dramatic hole opening up over Antarctica every year caused by complex meteorological and chemical processes.

In 1987, just seven years after scientists discovered man-made chemicals were damaging the ozone layer, the Montreal Protocol was signed to try and curb the amount of harmful chemicals in the atmosphere.

Previously found in refrigerators, air conditioners, hair spray and industrial cleaning products these chemicals started to be phased out to protect the ozone layer. Agreed by all 197 parties, this was one of the first ever universally ratified treaties in United Nations history.

Now, new research from the National Oceanic and Atmospheric Administration (NOAA) in the US has found that concentrations of harmful chemicals that damage the ozone layer have dropped.

In early 2022, NOAA scientists found that concentrations of harmful chemicals had declined by just over 50 per cent in the mid-level of the stratosphere compared to the 1980s.

Scientists at the NOAA say it is a “significant milestone” on the path to recovery.

Recovery of the ozone layer isn’t a “forgone conclusion”, however, as atmospheric levels of these damaging chemicals need to continue declining.

Concentrations of these chemicals over Antarctica, where a hole appears every year, are also dropping but at a slower rate.

This hole was larger than usual - bigger than the size of the continent itself - in 2021. The NOAA predicts that the Antarctic ozone layer could eventually recover “sometime around 2070”.

Until it eventually