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.

“Observationally based studies such as ours are converging on the same large magnitude of black carbon heating as modeling studies from Stanford, Caltech and NASA,” said Ramanathan. “We now have to examine if black carbon is also having a large role in the retreat of arctic sea ice and Himalayan glaciers as suggested by recent studies.”

In the paper, Ramanathan and Carmichael integrated observed data from satellites, aircraft and surface instruments about the warming effect of black carbon and found that its forcing, or warming effect in the atmosphere, is about 0.9 watts per meter squared. That compares to estimates of between 0.2 watts per meter squared and 0.4 watts per meter squared that were agreed upon as a consensus estimate in a report released last year by the Intergovernmental Panel on Climate Change (IPCC), a U.N.-sponsored agency that periodically synthesizes the body of climate change research.

Ramanathan and Carmichael said the conservative estimates are based on widely used computer model simulations that do not take into account the amplification of black carbon’s warming effect when mixed with other aerosols such as sulfates. The models also do not adequately represent the full range of altitudes at which the warming effect occurs. The most recent observations, in contrast, have found significant black carbon warming effects at altitudes in the range of 2 kilometers (6,500 feet), levels at which black carbon particles absorb not only sunlight but also solar energy reflected by clouds at lower altitudes.

Between 25 and 35 percent of black carbon in the global atmosphere comes from China and India, emitted from the burning of wood and cow dung in household cooking and through the use of coal to heat homes. Countries in Europe and elsewhere that rely heavily on diesel fuel for transportation also contribute large amounts.

“Per capita emissions of black carbon from the United States and some European countries are still comparable to those from south Asia and east Asia,” Ramanathan said.

In south Asia, pollution often forms a prevalent brownish haze that has been termed the “atmospheric brown cloud.” Ramanathan’s previous research has indicated that the warming effects of this smog appear to be accelerating the melt of Himalayan glaciers that provide billions of people throughout Asia with drinking water. In addition, the inhalation of smoke during indoor cooking has been linked to the deaths of an estimated 400,000 women and children in south and east Asia.

Elimination of black carbon, a contributor to global warming and a public health hazard, offers a nearly instant return on investment, the researchers said. Black carbon particles only remain airborne for weeks at most compared to carbon dioxide, which remains in the atmosphere for more than a century. In addition, technology that could substantially reduce black carbon emissions already exists in the form of commercially available products.

Ramanathan said that an observation program for which he is currently seeking corporate sponsorship could dramatically illustrate the benefits. Known as Project Surya, the proposed venture would provide some 20,000 rural Indian households with smoke-free cookers and equipped to transmit data. At the same time, a team of researchers led by Ramanathan would observe air pollution levels in the region to measure the effect of the cookers.

Carmichael said he hopes that the paper’s presentation of the immediacy of the benefits will make it easier to generate political and regulatory momentum toward reduction of black carbon emissions.

“It offers a chance to get better traction for implementing strategies for reducing black carbon,” he said.

The National Science Foundation, the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration funded the review.

1. For about the past three months, residents of  Modiin-Maccabim-Reut have been engulfed by unpleasant and acrid fumes every
   night.  Many residents have complained about burning eyes and nausea.
2. The sources of burning tires were identified from the Arab villages in Judea & Samaria adjacent to Modiin-Maccabim-Reut, as well as from pirate garbage dumps in the area of the Arab village of Naalin, near Kiryat Sefer and Hashmonaim. Each night, one can see a landscape of huge illegal bonfires of burning garbage from the Naalin road.
3. Residents of the area, instead of dumping their garbage in an approved dumping site, burn the garbage close to the road to the village of Naalin, including materials that are forbidden to burn such as batteries, chemical substances, nylon sheeting, etc. The terrible fumes and smoke that erupt every night from the garbage heaps, are borne by wind to the settlements of Kiryat Sefer, Hashmonaim, and Modiin-Maccabim-Reut.
4. Recently, I also learned that Israeli trucks pass by the checkpoint and arrive at these garbage dumps in order to save on the cost of dumping their garbage at approved Israeli dumping centers which apparently charge more than dumping at Naalin.
5. My recommendation is to implement a number of steps which will help in curbing this situation:

• Send clear instructions to soldiers at the checkpoints on the road to Naalin, not to allow the passage of Israeli garbage trucks to these dumping sites.
• These dumping sites should be closed by the army, and garbage redirected to legal dumping sites. To remind you: In addition to the high air pollution that both Arab and Jewish residents alike suffer from, garbage that is not properly treated has severe detrimental effects on the environment, such as seepage of toxic substances into the nearby water aquifer, passage of pesticides and dangerous chemicals are transported via birds to Israeli agricultural fields, and so on. When uncontrolled burning of garbage takes place, hydrogen sulphate and dioxides escape into the air, which are very dangerous to human breathing.