Global ozone has been declining since the 1970s owing to certain man-made chemicals. Since these were banned, parts of the layer have been recovering, particularly at the poles.
However, the new result, published today in the European Geosciences Union journal Atmospheric Chemistry and Physics, finds that the bottom part of the ozone layer at more populated latitudes is not recovering. The cause is currently unknown.
Ozone is a substance that forms in the stratosphere – the region of the atmosphere between about 10 and 50 km altitude, above the troposphere that we live in. It is produced in tropical latitudes and distributed around the globe.
A large portion of the resulting ozone layer resides in the lower part of the stratosphere. The ozone layer absorbs much of the UV radiation from the Sun, which, if it reaches the Earth’s surface, can cause damage to DNA in plants, animals and humans.
Read more at Imperial College London
Image: The ozone layer is recovering at the poles, but unexpected decreases in part of the atmosphere may be preventing recovery at lower latitudes. (Credit: NASA)