Soot: The Critical Factor
June 2008 (Draft)
Dark Carbon Aerosols Causing Warming Then And Now
- Dark Carbon Aerosols May Be Generating More Warming Than Green House Gases
- Implications for Future International Policy and Technology Development
- Simple Solutions To Warming Can Generate Unprecedented Economic Wealth
This comprehensive PDF report on soot’s warming effects has many links to supporting research, pg.169-179.
Specific sections can be quickly read to provide substantial background on the problems and policy solutions:
- brief synopsis, page 3
- preface, page 9
- chapter 2, page 51
April 25, 2008
How do mercury emissions affect pregnant mothers, the unborn and toddlers? Do the level of emissions impact autism rates? Does it matter whether a mercury-emitting source is 10 miles away from families versus 20 miles? Is the risk of autism greater for children who live closer to the pollution source?
A newly published study of Texas school district data and industrial mercury-release data, conducted by researchers at The University of Texas Health Science Center at San Antonio, indeed shows a statistically significant link between pounds of industrial release of mercury and increased autism rates. It also shows—for the first time in scientific literature—a statistically significant association between autism risk and distance from the mercury source.
- Mercury-release data examined were from 39 coal-fired power plants and 56 industrial facilities in Texas.
- Autism rates examined were from 1,040 Texas school districts.
- For every 1,000 pounds of mercury released by all industrial sources in Texas into the environment in 1998, there was a corresponding 2.6 percent increase in autism rates in the Texas school districts in 2002.
- For every 1,000 pounds of mercury released by Texas power plants in 1998, there was a corresponding 3.7 percent increase in autism rates in Texas school districts in 2002.
- Autism prevalence diminished 1 percent to 2 percent for every 10 miles from the source.
- Mercury exposure through fish consumption is well documented, but very little is known about exposure routes through air and ground water.
- There is evidence that children and other developing organisms are more susceptible to neurobiological effects of mercury.
Mercury In California Rainwater Traced To Industrial Emissions In Asia
December 20, 2002
Industrial emissions in Asia are a major source of mercury in rainwater that falls along the California coast, according to a new study by researchers at the University of California, Santa Cruz. The researchers reported their findings in a paper published online today by the Journal of Geophysical Research - Atmospheres. (The paper will appear in print in a later issue of the journal.)
Brown Carbon Spheres in East Asian Outflow and Their Optical Properties
August 8, 2008
Vol. 321. no. 5890, pp. 833 - 836
Duncan T. L. Alexander, Peter A. Crozier, James R. Anderson
Atmospheric aerosols play a substantial role in climate change through radiative forcing. Combustion-produced carbonaceous particles are the main light-absorbing aerosols; thus, quantifying their optical properties is essential for determining the magnitude of direct forcing. By using the electron energy-loss spectrum in the transmission electron microscope, we quantified the optical properties of individual, submicrometer amorphous carbon spheres that are ubiquitous in East Asian–Pacific outflow. The data indicate that these common spheres are brown, not black, with a mean refractive index of 1.67 – 0.27i (where i = ) at a wavelength of 550 nanometers. The results suggest that brown carbon aerosols should be explicitly included in radiative forcing models.
Black Carbon Pollution Emerges As Major Player In Global Warming
Mar. 24, 2008
Black carbon, a form of particulate air pollution most often produced from biomass burning, cooking with solid fuels and diesel exhaust, has a warming effect in the atmosphere three to four times greater than prevailing estimates, according to scientists in an upcoming review article in the journal Nature Geoscience.
Scripps Institution of Oceanography at UC San Diego atmospheric scientist V. Ramanathan and University of Iowa chemical engineer Greg Carmichael, said that soot and other forms of black carbon could have as much as 60 percent of the current global warming effect of carbon dioxide, more than that of any greenhouse gas besides CO2. The researchers also noted, however, that mitigation would have immediate societal benefits in addition to the long term effect of reducing greenhouse gas emissions.
Study Fingers Soot as a Major Player in Global Warming
March 28, 2008
Vol. 319. no. 5871, p. 1745
Robert F. Service
Climate-change authorities long ago tagged carbon dioxide public enemy number one. Now, there may be a new number two: tiny particles of black carbon, or soot. According to a new analysis reported online this week in Nature Geoscience, climate scientists are concluding that reports such as last November's assessment by the Intergovernmental Panel on Climate Change (IPCC) may seriously underestimate black carbon's role in global warming. The good news is that--unlike reductions in greenhouse gas emissions--reducing the release of large amounts of black carbon worldwide would have immediate effects.
Although the error bars on the new measurement are large, "the effects of black carbon are definitely stronger than what the IPCC estimates," says Mark Jacobson, an atmospheric scientist at Stanford University in Palo Alto, California, who was not involved in the study.
The IPCC report noted that black carbon is a strong absorber of sunlight but downplayed its impact because the haze it produces occurs regionally rather than globally. IPCC estimated that, at current levels, black carbon warms the atmosphere by 0.2 to 0.4 watts per square meter (W m-2), considerably below the value of 1.66 W m-2 for CO2. But in their new analysis of a wide variety of recent data, Veerabhadran Ramanathan of the Scripps Institution of Oceanography in San Diego, California, and Gregory Carmichael of the University of Iowa in Iowa City suggest that black carbon warms the atmosphere by as much as 0.9 W m-2--enough to vault it over the impact of other climate-warming gases such as methane, halocarbons, and tropospheric ozone.
Dirty Snow May Warm Arctic As Much As Greenhouse Gases
Today @ UCI, Irvine, California
June 6, 2007
Burning cleaner fuel would brighten snow and lower temperatures.
The global warming debate has focused on carbon dioxide emissions, but scientists at UC Irvine have determined that a lesser-known mechanism – dirty snow – can explain one-third or more of the Arctic warming primarily attributed to greenhouse gases.
Dirty snow has had a significant impact on climate warming since the Industrial Revolution. In the past 200 years, the Earth has warmed about .8 degree Celsius. Zender, graduate student Mark Flanner, and their colleagues calculated that dirty snow caused the Earth’s temperature to rise .1 to .15 degree, or up to 19 percent of the total warming.
In the past two centuries, the Arctic has warmed about 1.6 degrees. Dirty snow caused .5 to 1.5 degrees of warming, or up to 94 percent of the observed change, the scientists determined.
Pollutant Haze Heats the Arctic
University of Utah
May 10, 2006
Arctic climate already is known to be particularly prone to global warming caused by industrial and automotive emissions of carbon dioxide and other greenhouse gases. Now, a University of Utah study finds a surprising new way society’s pollutants warm the far north: the Arctic’s well-known haze – made of particulate pollution from mid-latitude cities – mixes with thin clouds, making them better able to trap heat.
The effect makes the Arctic 2 degrees to 3 degrees Fahrenheit warmer during polluted, cloudy episodes than it would be if the air was clean, concludes the study by Tim Garrett, an assistant professor of meteorology, and Chuanfeng Zhao, a doctoral student in meteorology...
“Now we are finding there is another way pollution can warm up the Arctic. Particulate pollution from factories and cars can be transported long distances to the Arctic, where it changes clouds so that they become more effective blankets, trapping more heat and further aggravating climate warming.”
Arctic haze has been seen in the Arctic since the Industrial Revolution began about 1750. “Whalers and explorers noticed what looked like pollution and couldn’t figure out where it was coming from,” Garrett says. The Inuit (Eskimos) called it “poo-jok.”
Southern Hemisphere and Deep-Sea Warming Led Deglacial Atmospheric CO2 Rise and Tropical Warming
October 19, 2007
Vol. 318. no. 5849, pp. 435 - 438
Lowell Stott, Axel Timmermann, Robert Thunell
Establishing what caused Earth's largest climatic changes in the past requires a precise knowledge of both the forcing and the regional responses. We determined the chronology of high- and low-latitude climate change at the last glacial termination by radiocarbon dating benthic and planktonic foraminiferal stable isotope and magnesium/calcium records from a marine core collected in the western tropical Pacific. Deep-sea temperatures warmed by ~2°C between 19 and 17 thousand years before the present (ky B.P.), leading the rise in atmospheric CO2 and tropical–surface-ocean warming by ~1000 years. The cause of this deglacial deep-water warming does not lie within the tropics, nor can its early onset between 19 and 17 ky B.P. be attributed to CO2 forcing. Increasing austral-spring insolation combined with sea-ice albedo feedbacks appear to be the key factors responsible for this warming.
Asian Soot, Smog May Boost Global Warming in US
Seth Borenstein, AP Science Writer
September 4, 2008
WASHINGTON - Smog, soot and other particles like the kind often seen hanging over Beijing add to global warming and may raise summer temperatures in the American heartland by three degrees in about 50 years, says a new federal science report released Thursday.
These overlooked, shorter-term pollutants — mostly from burning wood and kerosene and from driving trucks and cars — cause more localized warming than once thought, the authors of the report say. They contend there should be a greater effort to attack this type of pollution for faster results.