Scientists have reported that the ozone hole over Earth’s southern pole spans nearly 20 million square kilometers this year, almost three times the size of the contiguous United States, while simultaneously signaling promising progress in global environmental recovery efforts.
The ozone hole reached its maximum extent of 22.4 million square kilometers (8.5 million square miles) on September 28, marking what researchers describe as a relatively small depletion compared with historical measurements.
The ozone layer, a critical atmospheric shield, protects Earth from harmful ultraviolet radiation. Depleted ozone regions allow increased ultraviolet light exposure, which can lead to higher rates of skin cancer, reduced agricultural yields and damage to delicate ecosystems.
This year’s hole ranks as the seventh smallest since recovery began in 1992, following the implementation of the landmark Montreal Protocol, an international agreement designed to phase out ozone-depleting chemicals.
“The 2024 Antarctic hole is smaller than ozone holes seen in the early 2000s,” said Paul Newman, leader of NASA‘s ozone research team and chief scientist for Earth sciences at NASA’s Goddard Space Flight Center, in a statement.
NASA Earth Observatory
“The gradual improvement we’ve seen in the past two decades shows that international efforts that curbed ozone-destroying chemicals are working,” he said.
The current reduction in the ozone hole stems from a combination of declining chlorofluorocarbon (CFC) levels and unexpected ozone infusions from air currents north of Antarctica. The Montreal Protocol, signed in 1987, played a crucial role by compelling countries worldwide to replace harmful chemicals with environmentally friendly alternatives by 2010.
By the mid-1980s, the ozone layer had thinned significantly, leaving large areas of the Antarctic stratosphere nearly ozone-free by early October each year.
Major sources of ozone-depleting CFCs include coolants used in refrigerators and air conditioners, along with aerosols found in products like hair spray, antiperspirants and spray paints. Additionally, the production of insulating foams and certain industrial fire suppression systems released these harmful chemicals into the atmosphere.
Stephen Montzka of NOAA’s Global Monitoring Laboratory said in a statement that while the 2024 measurements are encouraging, “the ozone layer is still far from being fully healed.”
Researchers continue to monitor the ozone layer using sophisticated instruments aboard NASA’s Aura satellite, NOAA-20 and NOAA-21 satellites and the Suomi NPP satellite. Additional data comes from weather balloons launched from the South Pole Baseline Atmospheric Observatory, which recorded the lowest ozone concentration of 109 Dobson units on October 5.
Scientists project that if current trends continue, the ozone layer could fully recover by 2066, marking a significant triumph of international environmental cooperation and scientific innovation.
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