The peak size of the ozone hole over Antarctica in 2024 was the seventh smallest since recovery began, NASA and the National Oceanic and Atmospheric Administration (NOAA) have found. Even its maximum size was smaller than it has been in five years, since the even smaller gap in 2019.
The monthly average was around 20 million square kilometers (8 million square miles), while the peak was reached on September 28 at 22.4 million square kilometers (8.5 million square miles). In the worst case, in the year 2000, the gap was 50 percent larger and much more depleted.
“The Antarctic hole in 2024 will be smaller than the ozone holes we saw in the early 2000s,” Paul Newman, leader of NASA’s ozone research team and chief scientist for earth sciences at NASA’s Goddard Space Flight Center, said in a statement. “The gradual improvement we have seen over the past two decades shows that international efforts to curb ozone-destroying chemicals are working.”
Our atmosphere has a layer rich in ozone, a molecule consisting of three oxygen atoms. Ozone absorbs ultraviolet radiation from the sun – a crucial protection, as UV light can harm us.
In the 1970s, ozone concentrations (measured in Dobson units) began to decline, and scientists discovered that chlorofluorocarbons (CFCs) were responsible for this destruction. In the mid-1980s, large parts of the Antarctic stratosphere had virtually no ozone by early October each year. This year the concentration was 107 Dobsonian units, just over half of what it was in 1979.
“For 2024, we could see the severity of the ozone hole being below average compared to other years over the past 30 years, but the ozone layer is still far from being completely healed,” explains Stephen Montzka, senior scientist at the NOAA Global Monitoring Laboratory . .
“That is well below the 225 Dobson units that were typical for the ozone layer over Antarctica in 1979,” added NOAA research chemist Bryan Johnson. “So there is still a long way to go before the ozone layer in the atmosphere returns to the level it was before the advent of widespread CFC pollution.”
The agencies estimate that the ozone hole is still on track to close permanently by 2066 and that global ozone levels will return to pre-1980 levels by 2040. This was only possible thanks to the Montreal Protocol, which banned the depletion of the ozone layer. chemicals. To say it was a groundbreaking international agreement is almost understatement: it is one of the few United Nations treaties that has been ratified by every country in the world, and it truly shows what we can do when humanity works together.