When can the ozone layer fully recover?

Ozone concentrations over the Arctic hit an all-time high in March of this year, according to a study by NASA’s Goddard Space Flight Center.

Warmer weather and a slower jet stream have increased the thickness of the protective gas layer by 14.5% compared to the post-1980 average.

Scientists say the ban of chlorofluorocarbons (CFCs) under the 1989 Montreal Protocol means the ozone layer is now heading towards… Full recovery by 2045.

The lead author of the study, Dr. Paul Newman, stressed that “the increase in ozone levels represents positive news, as it reflects the success of the Montreal Protocol and its beneficial effects on the environment.”

The ozone layer is defined as an envelope of ozone, a molecule made up of 3 oxygen atoms, that surrounds the Earth.

This layer absorbs harmful ultraviolet rays from the sun, which protects life on the planet from diseases such as cancer, burns and blindness.

In 1985, scientists from the British Antarctic Survey realized that human activity had created a complete hole in the ozone layer above the poles. In 1989, chlorofluorocarbons, mainly responsible for the deterioration of the ozone layer, were banned, but there has been no clear recovery yet.

Now, NASA scientists have made an encouraging discovery: ozone concentration over the Arctic reached a record high in March.

The thickness of the ozone layer is measured using a unit of measurement known as “Dobson units,” which indicates the amount of ozone in a column of air extending from the Earth’s surface into space.

In March of this year, the average thickness of the ozone layer over the Arctic reached 477 Dobson units, which is six Dobson units higher than the previous record, and 60 Dobson units higher than the average for the period between 1979 and 2023.

On March 12, a new record high of 499 Dobson units was set.

After peaking in March, ozone levels continued to rise, breaking records for monthly averages in the following months from May to August, which is very positive for life on Earth, as the deterioration of the ozone layer allows in large amounts of ultraviolet radiation.

In March, scientists estimated that the UV index was 6 to 7 percent lower in the Arctic, and 2 to 6 percent lower in the mid-latitudes of the Northern Hemisphere, representing a significant change compared to March 2020. The ozone hole over the North Pole has been discovered to have expanded to a record size, contributing to rising temperatures in the region.

Scientists suggested that these changes are due to global weather systems that changed the distribution of the atmosphere during the winter.

Some models suggest a one in eight chance of ozone levels rising to a record high by 2025. Scientists predict more record years in the future, meaning the ozone layer could recover to pre-1980s levels by 2045.

The study was published in Geophysical Research Letters.

Source: Daily Mail