Revealed: The 2024 ozone hole over the Antarctic is reported to be the 7th smallest since 1992 when NASA predicted the date the layer could close.
Almost forty years have passed since scientists discovered a growing hole in the Earth’s ozone layer.
But climate researchers now say that the protective shield, about 20 kilometers above our planet, may be on the way to recovery.
New data collected by NASA show that the ozone hole over the Antarctic this year was the seventh smallest since 1992.
NASA and the National Oceanic and Atmospheric Administration (NOAA) predict that the layer may fully recover as soon as 2066.
Dr Paul Newman, leader of NASA’s ozone research team, says: ‘The 2024 Antarctic hole is smaller than the ozone holes seen in the early 2000s.
‘The gradual improvement we have seen over the past two decades shows that international efforts to ban ozone-depleting chemicals are working.’
However, the ozone hole still covered an average of about 8 million square kilometers (20 million square kilometers) – three times the size of than the contiguous United States.
Scientists warn that there is still a long way to go before the ozone layer returns to its natural thickness.
NASA revealed that the hole in the ozone layer (pictured) was at its seventh level since 1992 this year.
When the ozone hole opens up it allows more levels of harmful UVB rays to hit the Earth which increases the risks of eye and eye cancer.
Each year, a combination of ozone-depleting chemicals and cold temperatures combine to open an annual ozone hole above the Antarctic.
Although this hole still allows harmful ultraviolet rays to rain into the Antarctic every year, it has recently started to show promising signs of recovery.
Using a combination of satellite observations and ground-launched weather balloons, NASA and NOAA have measured the amount of ozone gas in the atmosphere.
Their observations revealed that the annual ozone layer above the South Pole was relatively small compared to other years during its peak depletion between September 7 and October 13.
At its largest on September 28 this year, the ozone hole covered an area of 8.5 million square kilometers (22.4 million square miles).
This will be a big difference from 2023, where the ozone hole reached a peak of 10 million square kilometers (26 million miles) on September 10.
While that’s still significant, it’s the 20th smallest hole since records began in 1979 and the seventh largest since ozone-depleting CFCs were banned under the accord. Montreal.
At its largest point this year the ozone hole was 8.5 million square kilometers (22.4 million miles) on September 28. This is 1.5 million square kilometers more than the peak size in 2023.
NASA and National Oceanic and Atmospheric Administration (NOAA) scientists measured the ozone layer over the Antarctic using satellites and weather balloons (pictured). They now predict that the ozone layer may recover completely by 2066
CFCs (chlorofluorocarbons) are a type of man-made chemical that was widely used in aerosols and refrigerants.
Since they were legally banned in 1992, the concentration of CFCs in the atmosphere has gradually decreased, allowing the ozone layer to begin to recover.
A recent study by the Copernicus Atmosphere Monitoring Service (CAMS) found that the ozone hole took longer to form and is smaller than expected.
On September 13, the ozone hole was 18.48 million square kilometers (7.13 million miles), smaller than the same period in recent years.
Meanwhile, the ozone layer above the North Pole has also shown signs of possible recovery.
This year, exceptionally good weather allowed the Arctic ozone layer to be 14.5 percent thicker than the post-1980 average.
According to NASA and NOAA estimates, this means that the ozone layer could return to its pre-hole thickness in just over 40 years.
Scientists believe that the recent recovery is due to the natural decline of CFCs combined with the flow of ozone from the north of the pole.
In September this year, the ozone hole (pictured in blue) was 7.13 million square kilometers – smaller than the same period in recent years. Researchers suggest that this is an indication that banning CFCs allows the ozone layer to recover naturally.
The ozone layer still has a long way to go until it recovers. On October 5 of this year (pictured) the layer reached a thickness of only 109 Dobson units, less than half of the pre-1979 average.
Ozone formed in the stratosphere usually absorbs almost all the rays from the sun, protecting life on Earth from harmful radiation.
During the winter months, rotating winds called the Polar Vortex often transport ozone-depleting chemicals to a small area above the South Pole.
Then, when energy from the sun begins to hit the atmosphere in the spring, the combination of cold temperatures and solar radiation begins to destroy the ozone layer.
However, in June Antarctica experienced two ‘extraordinary stratospheric warming events’ which caused the surface temperature to jump 15ºC (27ºF) and 17ºC (30.6ºF) respectively.
These spikes weakened the Polar Vortex significantly, slowing the rate of subsidence and allowing more ozone to reach the pole surface.
However, NASA also warns that the ozone layer still has a long way to recover.
Stephen Montzka, senior scientist at the NOAA Global Monitoring Laboratory, says: ‘In 2024, we can see that the depth of the ozone hole is below average compared to other years in the last three decades, but the layer The ozone layer is still far from being fully recovered. .’
Scientists measure the thickness of the ozone layer using a measure called Dobson units where anything less than 220 Dobson units (DU) is considered an ozone hole.
At its thinnest point this year on October 5, the atmosphere above the Antarctic measured just 109 DU.
Recent studies have shown that the ozone layer is making promising progress toward recovery. This graph shows that the Antarctic ozone hole formed later and was smaller than expected this year
Researchers found that the ozone layer over the Arctic reached a record thickness in March 2024 (right). This is in stark contrast to March 2020 (left) when a ruptured ozone hole opened over the pole.
That’s slightly thinner than the lowest level ever recorded when the ozone layer hit 92 DU in 2006, but still thin enough to cause serious health risks.
A recent study even found that Antarctic wildlife such as seals and penguins are at greater risk of sunburn due to ozone depletion.
According to Bryan Johnson, a NOAA research chemist, 225 Dobson parts were equivalent to the ozone layer over the Antarctic in 1979.
‘So there is still a long way to go before atmospheric ozone returns to levels before the advent of widespread CFC pollution,’ he said.
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