Read the text below.
Scientists discovered that the ozone hole over Antarctica shrank to its smallest size since it was discovered in 1982.
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) have observed that the Antarctic ozone hole measured an average of 9.3 million square kilometers this year. This is a major improvement from its peak in 2006 when it averaged 26.6 million square kilometers.
The ozone layer serves as a screen that keeps harmful ultraviolet radiation from reaching the Earth’s surface. However, chemicals such as chlorofluorocarbons (CFCs) commonly found in aerosol sprays and refrigerators harm the ozone layer.
To reduce CFCs’ harmful effects, governments around the world created the Montreal Protocol, which bans the use of chemicals that deplete the ozone. The ban caused the hole to shrink slightly, and the ozone is expected to recover by 2070 as CFCs in the atmosphere decline.
However, while the hole’s shrinking is great news, NASA Chief Scientist Paul Newman said that it was not due to the efforts to reduce CFCs. Rather, the shrinking was caused by the unusually warm temperature in the Earth’s atmosphere.
Newman said that man-made compounds need cold temperatures to transform into chemicals that can destroy the ozone. However, when atmospheric temperatures are warmer, the chemicals do not form, and ozone destruction becomes limited. So, he explained that the phenomenon is actually due to irregular weather patterns in the Antarctic region and not to the fact that the ozone is on the road to recovery.