Previously, scientists believed that greenhouse gases, especially CO2, primarily affected the lowest regions of the atmosphere. However, new findings from atmospheric scientist Benjamin D. Santer at the Lawrence Livermore National Laboratory (USA) and his colleagues indicate that we need to reconsider this assessment.
The upper atmosphere layer above Earth – Photo: NASA Earth Observation Center
According to their latest research, the height of the stratospheric layer has decreased by 400 meters over the past 40 years. Additionally, the mesosphere and lower thermosphere have contracted by 1,341 meters between 2002 and 2019. These observations have been confirmed by Petr Pišoft, an atmospheric physicist at Charles University in Prague, through analysis of NASA data.
The contraction of the atmosphere implies a decrease in its density, reducing drag on satellites in low orbit. It also prolongs the presence of space debris and increases the risk of collisions. Currently, there are over 5,000 satellites in high and low Earth orbits, not including the International Space Station (ISS).
Notably, the ozone molecules in the atmosphere, which shield Earth from combustion, will also become thinner due to the contraction of the upper atmospheric layer.
“The current increase in CO2 levels is discernible throughout the entire atmosphere. It is driving significant changes that scientists are only beginning to comprehend,” warns Martin Mlyncsak, an atmospheric physicist at NASA’s Langley Research Center in Hampton, Virginia.
The study, published in the Proceedings of the National Academy of Sciences (PNAS), sheds light on the alarming trends in Earth’s atmosphere.