According to the new study published in the journal Environmental Research Letters, the thickness of the atmospheric layer has contracted by 400 metres since the 1980s and will thin by about another kilometre by 2080 without major cuts in emissions.
- The stratosphere extends from about 20km to 60km above the Earth’s surface and is around 40 kilometers thick. In the troposphere carbon dioxide heats and expands the air which pushes up the lower boundary of the stratosphere. But, in addition, when CO2 enters the stratosphere it actually cools the air, causing it to contract.
- The ozone layer that absorbs Ultraviolet rays from the sun is in the stratosphere and researchers had thought ozone losses in recent decades could be to blame for the shrinking.
- Less ozone means less heating in the stratosphere. But the new research shows it is the rise of carbon dioxide that is behind the steady contraction of the stratosphere, not ozone levels, which started to rebound after the 1989 Montreal treaty banned CFCs.
- The study says that these changes in the stratosphere have the potential to affect satellite operations, the GPS navigation system and radio communications.
