Black carbons -- arising from such sources as diesel engine exhaust and cooking fires -- are widely considered a factor in global warming and are an important component of air pollution around the world, according to Greg Carmichael, Karl Kammermeyer Professor of Chemical and Biochemical Engineering in the UI College of Engineering and co-director of the UI's Center for Global and Regional Environmental Research. Sulfates occur in the atmosphere largely as a result of various industrial processes.
Carmichael's colleagues in the study were V. Ramanathan and Y. Feng of Scripps Institution of Oceanography, La Jolla, Calif.; S-C. Yoon and S-W. Kim of Seoul National University, South Korea; and J. J. Schauer of the University of Wisconsin, Madison.
In order to conduct their study, the researchers made ground-level studies of air samples at Cheju Island, South Korea, and then sampled the air at altitudes between 100 and 15,000 feet above the ground using unmanned aircrafts (UAVs).
They found that the amount of solar radiation absorbed increased as the black carbon to sulphate ratio rose. Also, black carbon plumes derived from fossil fuels were 100 percent more efficient at warming than were plumes arising from biomass burning.
"These results had been indicated by theory but not verified by observations before this work," Carmichael said. "There is currently great interest in developing strategies to reduce black carbon as it offers the opportunity to reduce air pollution and global warming at the same time."
The authors suggest that climate mitigation policies should aim to reduce the ratio of black carbon to sulphate in emissions, as well as the total amount of black carbon released.
In a paper published in May 2008 in Nature Geoscience, Carmichael and Ramanathan found that black carbon soot from diesel engine exhaust and cooking fires -- widely used in Asia -- may play a larger role than previously thought in global warming. They said that coal and cow dung-fueled cooking fires in China and India produce about one-third of black carbon; the rest is largely due to diesel exhaust in Europe and other regions relying on diesel transport. The paper also noted that soot and other forms of black carbon could equal up to 60 percent of the current global warming effect of carbon dioxide, the leading greenhouse gas.
Carmichael is chair of the scientific advisory group for the World Meteorological Organization's GURME (Global atmospheric watch Urban Research Meteorology and Environment) project and chair of the scientific advisory group for the Shanghai Expo pilot project on air quality forecasting. He has worked with Shanghai authorities for three years to help develop an early warning system for air quality problems and heat waves.
The study was funded by National Science Foundation.
STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500.
MEDIA CONTACT: Gary Galluzzo, 319-384-0009, firstname.lastname@example.org
Jennifer Brown | EurekAlert!
New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg
Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences