MessageToEagle.com - The Earth’s climate is changing rapidly and scientists are trying to find out what’s
exactly causing this change.
Not only carbon dioxide contributes to global warming.
In addition to causing smoggy skies and chronic coughs, soot -- or black carbon -- turns out
to be the number two contributor to global warming. It's second only to carbon dioxide, according to a four-year
assessment by an international panel.
Carbon dioxide is rising because of human actions: Scientists can measure the increase of atmospheric
carbon dioxide over the last 150 years. By comparing the type of carbon being added to the atmosphere, they
see that the kind of carbon released by burning coal, gasoline, and natural gas is diluting the naturally-
occurring carbon dioxide in the atmosphere. Data from Trudinger, et al (1999). Image Credit: Steve Newton for NCSE, in 2012.
"We were surprised at its potential contribution to climate," said Sarah Doherty, a University of Washington atmospheric
scientist and one of four coordinating lead authors. The silver lining may be that controlling these emissions can
deliver more immediate climate benefits than trying to control carbon dioxide, she said.
Black carbon's role in climate is complex. Dark particles in the air work to shade Earth's surface while warming
the atmosphere. Black carbon that settles on the surface of snow and ice darkens the surface to absorb more
sunlight and increase melting.
Finally, soot particles influence cloud formation in ways that can have either a
cooling or warming impact.
"Because of a lack of action to reduce carbon dioxide emissions, the policy community is asking what else we can do,
particularly to help places like the Arctic that are melting much more quickly than we had anticipated," Doherty said.
"We hope reducing black-carbon emissions buys us some time. But it doesn't replace cutting back on CO2 emissions."
While carbon dioxide has a half-life of 100 years, black carbon stays in the atmosphere for only a few days.
Researchers investigated various sources of black carbon to see which reductions might have the most short-term
Regulating emissions from diesel engines followed by replacing some wood- and coal-burning household
stoves, authors find, would have the greatest immediate cooling impact.
"If you're just thinking about impact on climate, you would want to be strategic about which sources you cut back on,"
Doherty, executive director of the International Global Atmospheric Chemistry Project
in 2009, said. "We looked at the overall impact because some of these sources also emit associated particles that
can have counteracting effects."
UW atmospheric scientists Sarah Doherty (left) and Stephen Warren (right) taking snow samples in Greenland in summer 2010.
Black carbon contributes to climate change in the mid to high latitudes, including the northern United States,
Canada, northern Europe and northern Asia, as well as affecting rainfall patterns of the Asian Monsoon.
The report incorporates data that Doherty and co-author Stephen Warren, a UW professor of atmospheric sciences,
gathered between 2007 and 2009 to measure soot on Arctic snow. Calculating black carbon deposits in the Arctic is
difficult, so data are essential for testing and correcting models.
"Mitigating black carbon is good for curbing short-term climate change, but to really solve the long-term climate
problem, carbon dioxide emissions must also be reduced," Tami Bond, first author at the University of Illinois, said.
UPDATE: Huge Stripe On The Sun - Is Earth In Serious Danger? UPDATE: This article has now been updated with additional information from NASA including images and video!
The Sun's odd behavior has been mentioned on many occasions recently. As we all await the Solar Cycle 24, scientists keep a close eye on the Sun.