Since its discovery in the 1980s, scientists have monitored the hole in the ozone layer above the South Pole to gauge how international policies impact climate change. 

This year, after a “pretty standard start,” the ozone hole quickly grew beyond expectations, scientists at the Copernicus Atmosphere Monitoring Service (CAMS) said Thursday. 


What You Need To Know

  • The hole in the ozone layer has "evolved into a rather larger than usual one,” scientists from the Copernicus Atmosphere Monitoring Service (CAMS) said Thursday

  • The hole in the ozone forms annually during the southern hemisphere’s spring season, beginning in August and typically lasting through October

  • CAMS, a subsidiary of the European Union’s space program, compares ozone records spanning decades to see if efforts like the 1987 Montreal Protocol impact the size of the hole

  • Scientists found that since the ban on halocarbons was enacted, the ozone layer “has shown signs of recovery,” but progress remains slow

The hole in the ozone forms annually during the Southern Hemisphere’s spring season, beginning in August and typically lasting through October. The maximum size of the hole typically appears in mid-September into October. 

This year’s ozone hole grew at largely the same rate as it did in 2020, which proceeded at an unexceptional pace through the beginning of September. Soon after September hit, the hole “turned into one of the longest-lasting ozone holes in our data record” for so late in the season, CAMS director Vincent-Henri Peuch wrote in a statement. 

“Now our forecasts show that this year´s hole has evolved into a rather larger than usual one,” Peuch continued. “We are looking at a quite big and potentially also deep ozone hole.”

While the hole itself may be larger than in previous years, Peuch said the temperatures in the surrounding stratosphere are actually lower now than in years past. 

That means the ozone hole may last later into this year, as zone depletion slows when temperatures start to rise in the summer, and levels tend to return to normal by December. 

The ozone layer protects Earth from harmful ultraviolet sun rays; a depleted ozone layer can in turn lead to higher levels of certain cancers and cataracts and has a negative impact on agricultural productivity. 

A coalition of nearly 200 countries, including the United States, finalized the Montreal Protocol in 1987, an agreement meant to reduce the global consumption of products that lead to ozone depletion. Some harmful chemicals used in everyday cleaning products — halocarbons — were banned from use under the agreement.

CAMS, a subsidiary of the European Union’s space program, compares ozone records spanning decades to see if efforts like the Montreal Protocol impact the size of the hole. Scientists found that since the ban on halocarbons was enacted, the ozone layer “has shown signs of recovery,” but progress remains slow. 

"Since the ban on halocarbons, the ozone layer has slowly been recovering; the data clearly show a trend in decreasing area of the ozone hole," CAMS scientists wrote in part.

Experts say it will likely take until the 2060s or 2070s until all ozone-depleting chemicals are phased out of use.

The formation of the ozone hole year-to-year cannot be attributed to any one source, as it is caused by "complex meteorological and chemical processes," per CAMS. Stratospheric temperature plays a large role in ozone depletion, which is why the hole typically forms during warmer months.