Pinpointing pollutant sources is an important part of the ongoing battle to improve air quality and to understand its impact on climate. Scientists using NASA data recently tracked the path and distribution of aerosols — tiny particles suspended in the air — to link their region of origin and source type with their tendencies to warm or cool the atmosphere.
By altering the amount of solar energy that reaches the Earth’s surface, aerosols influence both regional and global climate, but their impact is difficult to quantify because most only stay airborne for about a week, while greenhouse gases can persist in the atmosphere for decades. In a study published Jan. 24 in the American Geophysical Union’s Journal of Geophysical Research-Atmospheres, researchers investigated the sources of aerosols and how different types of aerosols influence climate.
“This study offers details on the aerosol source regions and emission source types that policy makers could target to most effectively combat climate change,” said Dorothy Koch, lead author and atmospheric scientist at Columbia University and NASA’s Goddard Institute for Space Studies (GISS), New York.
Using a GISS computer model that includes a variety of data gathered by NASA and other U.S. satellites, the researchers simulated realistic aerosol concentrations of important aerosol types in the atmosphere and studied the amount of light and heat they absorb and reflect over several regions around the globe.
Each area has a unique mix of natural and pollutant aerosol sources that produces different types of aerosols and causes complex climate effects. The industry and power sectors are particularly important in North America and Europe and produce large amounts of sulfur dioxide, while Asia has higher emissions from residential sources, which produce relatively more carbon-containing aerosols.
“Computer model simulations showed that black carbon in the Arctic, a potentially important driver in climate change, derives its largest portion from Southeast Asian residential sources,” said Koch. “According to current model estimates, the residential sector appears to have a substantial potential to cause climate warming and therefore, could potentially be targeted to counter the effects of global warming.”
Black carbon, commonly called soot, is generated from motor vehicles and industrial pollution, in addition to outdoor fires and household burning of coal and bio-fuels. Soot is produced by incomplete combustion, especially of diesel fuels, coal and wood. Residential soot emissions are largest in areas where cooking and heating are done with wood, field residue, animal dung and coal.
