NOAA study: Increase in particles high in Earth’s atmosphere has offset some recent climate warming

July 21, 2011

A recent increase in the abundance of particles high in the atmosphere has offset about a third of the current climate warming influence of carbon dioxide (CO2) change during the past decade, according to a new study led by NOAA and published today in the online edition of Science

“Stratospheric aerosol increased surprisingly rapidly in that time, almost doubling during the decade,” Daniel said. “The increase in aerosols since 2000 implies a cooling effect of about 0.1 watts per square meter – enough to offset some of the 0.28 watts per square meter warming effect from the carbon dioxide increase during that same period.” Sources of aerosols reach the stratosphere from above and below, as shown in the graph. Sulfur dioxide (SO2), carbonyl sulfide (OCS), and dimethyl sulfide(DMS) are the dominant surface emissions which contribute to aerosol formation.
Download here. (Credit: NOAA)
The reasons for the 10-year increase in stratospheric aerosols are not fully understood and are the subject of ongoing research, says coauthor Ryan Neely, with the University of Colorado and the Cooperative Institute for Research in Environmental Sciences (CIRES).

(why not Sulfur comopounds or other aerosols injected into the atmosphere through an intentional aerosol injection program)



Likely suspects are natural sources – smaller volcanic eruptions – and/or human activities, which could have emitted the sulfur-containing gases, such as sulfur dioxide, that react in the atmosphere to form reflective aerosol particles. [link to www.noaanews.noaa.gov]