Geo- and Climate Science (Summary)

On the role of soot particles in the climate system

 

Author
Feichter, Johann

 

Department
The Atmosphere in the Earth System (Brasseur)

 

Corresponding Author
Feichter, Johann undefined e-mail

 

Abstract
Since begin of the industrial revolution levels of the greenhouse gases carbon dioxide, methane and nitrous oxide have risen dramatically. Fossil fuel combustion, increasingly intensive agriculture and an expanding global human population have been the primary causes for this rapid increase. The same increases in fossil fuel burning and biofuel use have also led to an increase in the emissions of sulphur dioxide, soot and particulate organic matter which form aerosol (=suspended particulate matter) in the atmosphere. Most aerosols cool the atmosphere by increasing Earth's reflectivity, but aerosols containing soot warm it by absorbing sunlight. Cleaner fuel technologies are today leading to a reduction in sulphate emissions. Unlike carbon dioxide and sulphur dioxide emissions, soot emissions are largest in developing countries and are still increasing. According to the IPCC SRES emission scenario A1b, the most polluted regions in the first part of the 21th century will be found at lower latitudes whilst aerosol emissions have decreased in North America and Europe. The most notable climate response as calculated by the MPI Earth-System Model to this latitudinal shift in atmospheric aerosol load is a mitigated surface warming and a wetter soil in highly polluted regions and a pronounced warming and drying in regions where the aerosol load is decreasing.