NASA finds soot has impact on global climate
NASA NEWS RELEASE
Posted: May 14, 2003

A team of researchers, led by NASA and Columbia University scientists, found airborne, microscopic, black-carbon (soot) particles are even more plentiful around the world, and contribute more to climate change, than was previously assumed by the Intergovernmental Panel of Climate Change (IPCC).

The researchers concluded if these soot particles are not reduced, at least as rapidly as light-colored pollutants, the world could warm more quickly.

The findings appear in the latest issue of the Proceedings of the National Academy of Sciences. It is authored by Makiko Sato, James Hansen and others from NASA's Goddard Institute for Space Studies (GISS) and Columbia University, New York; Oleg Dubovik, Brent Holben and Mian Chin of NASA's Goddard Space Flight Center, Greenbelt, Md.; and Tica Novakov, Lawrence Berkeley National Laboratory, Berkeley, Calif.

Sato, Hansen and colleagues used global atmospheric measurements taken by the Aerosol Robotic Network (AERONET). AERONET is a global network of more than 100 sun photometers that measure the amount of sunlight absorbed by aerosols (fine particles in the air) at wavelengths from ultraviolet to infrared. The scientists compared the AERONET data with Chin's global-aerosol computer model and GISS climate model, both of which included sources of soot aerosols consistent with the estimates of the IPCC.

The researchers found the amount of sunlight absorbed by soot was two-to-four times larger than previously assumed. This larger absorption is due in part to the way the tiny carbon particles are incorporated inside other larger particles: absorption is increased by light rays bouncing around inside the larger particle.

According to the researchers, the larger absorption is attributable also to previous underestimates of the amount of soot in the atmosphere. The net result is soot contributes about twice as much to warming the world as had been estimated by the IPCC.

Black carbon or soot is generated from traffic, industrial pollution, outdoor fires and household burning of coal and biomass fuels. Soot is a product of incomplete combustion, especially of diesel fuels, biofuels, coal and outdoor biomass burning. Emissions are large in areas where cooking and heating are done with wood, field residue, cow dung and coal, at a low temperature that does not allow for complete combustion. The resulting soot particles absorb sunlight, just as dark pavement becomes hotter than light pavement.

Both soot and the light-colored tiny particles, most of which are sulfates, pose problems for air quality around the world. Efforts are beginning to reduce the sulfate aerosols to address air quality issues.

"There is a pitfall, however, in reducing sulfate emissions without simultaneously reducing black carbon emissions," Hansen said. Since soot is black, it absorbs heat and causes warming. Sulfate aerosols are white, reflect sunlight, and cause cooling. At present, the warming and cooling effects of the dark and light particles partially balance.

This research continues observations of global climate change. It was funded by NASA's Earth Science Enterprise. The Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System Science to improve prediction of climate, weather, and natural hazards using the unique vantage point of space.

Apollo 11 special patch
Special collectors' patch marking the 35th anniversary of the historic Apollo 11 moon landing is now available.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Inside Apollo mission control
An insider's view of how Apollo flight controllers operated and just what they faced when events were crucial.
 Choose your store:
U.S.

The ultimate Apollo 11 DVD
This exceptional chronicle of the historic Apollo 11 lunar landing mission features new digital transfers of film and television coverage unmatched by any other.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Next ISS crew
Own a little piece of history with this official patch for the International Space Station's Expedition 11 crew. We'll ship yours today!
 Choose your store:
U.S.

Hubble Calendar
This remarkable calendar features stunning images of planets, stars, gaseous nebulae, and galaxies captured by NASA's orbiting Hubble Space Telescope.
 U.S. STORE
 U.K. & WORLDWIDE STORE

Hubble Posters
Stunning posters featuring images from the Hubble Space Telescope and world-renowned astrophotographer David Malin are now available from the Astronomy Now Store.
 U.S. STORE
 U.K. & WORLDWIDE STORE

Soviet Space
For the first time ever available in the West. Rocket & Space Corporation Energia: a complete pictorial history of the Soviet/Russian Space Program from 1946 to the present day all in full color. Available from our store.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Viking patch
This embroidered mission patch celebrates NASA's Viking Project which reached the Red Planet in 1976.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo 7 DVD
For 11 days the crew of Apollo 7 fought colds while they put the Apollo spacecraft through a workout, establishing confidence in the machine what would lead directly to the bold decision to send Apollo 8 to the moon just 2 months later.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Gemini 12
Gemini 12: The NASA Mission Reports covers the voyage of James Lovell and Buzz Aldrin that capped the Gemini program's efforts to prove the technologies and techniques that would be needed for the Apollo Moon landings. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo patches
The Apollo Patch Collection: Includes all 12 Apollo mission patches plus the Apollo Program Patch. Save over 20% off the Individual price.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.