Atmosphere cleans itself more efficiently than previously thought

The earth's atmosphere is less sensitive to pollutants than some researchers previously thought. An international team of researchers, including scientists from the Max Planck Institute for Chemistry in Mainz, has found that the concentration of hydroxyl radicals in the atmosphere has changed little in recent years.

Aidan Colton at NOAAs Mauna Loa Observatory demonstrates how flask samples were filled at the site. Air collected year-round at nine remote sites around the world has been analyzed for the industrial solvent methyl chloroform. Variability in the decay of this chemical has helped scientists understand the cleansing power of the global atmosphere and its sensitivity to natural and human-induced perturbations. © James Elkins, NOAA

Hydroxyl radicals clean the air by breaking down organic substances such as climate-damaging methane. Because this self-cleaning capacity has scarcely varied over the past few years, the researchers believe that it is only marginally affected by environmental changes.

These findings refute the view held by other scientists who believed that the atmosphere is very sensitive to air pollutants (Science, January 7, 2011).

Aidan Colton at NOAAs Mauna Loa Observatory demonstrates how flask samples were filled at the site. Air collected year-round at nine remote sites around the world has been analyzed for the industrial solvent methyl chloroform. Variability in the decay of this chemical has helped scientists understand the cleansing power of the global atmosphere and its sensitivity to natural and human-induced perturbations.

 We now have a clearer picture of how the atmosphere cleanses itself of air pollution and harmful gases.