"In California’s Los Angeles Basin, levels of some vehicle-related air pollutants have decreased by about 98 percent since the 1960s, even as area residents now burn three times as much gasoline and diesel fuel. Between 2002 and 2010 alone, the concentration of air pollutants called volatile organic compounds (VOCs) dropped by half, according to a new study by NOAA scientists and colleagues.
“The reason is simple: Cars are getting cleaner,” said Carsten Warneke, a NOAA-funded scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.
VOCs, primarily emitted from the tailpipes of vehicles, are a key ingredient in the formation of ground-level ozone which, at high levels, can harm people’s lungs and damage crops and other plants.
The magnitude of the drop in VOC levels was surprising, even to researchers who expected some kind of decrease resulting from California’s longtime efforts to control vehicle pollution.
“Even on the most polluted day during a research mission in 2010, we measured half the VOCs we had seen just eight years earlier,” Warneke said. “The difference was amazing.”
The study was published online today in the Journal of Geophysical Research-Atmospheres, a journal of the American Geophysical Union.
The 98 percent drop in VOCs in the last 50 years does not mean that ozone levels have dropped that steeply; the air chemistry that leads from VOCs to ozone is more complex than that. Ozone pollution in the Los Angeles Basin has decreased since the 1960s, but levels still don’t meet ozone standards set by the Environmental Protection Agency.
Requirements for catalytic converters, use of reformulated fuels less prone to evaporate, and improved engine efficiency of new vehicles have all likely contributed to overall declines in vehicle-related pollution, including VOCs.
The improvement in this one measure of air quality in Los Angeles may not surprise many longtime residents, Warneke said. People who lived in the city in the 1960s often couldn’t see nearby mountains through the smog; today, they often can.
For the new study, Warneke and his colleagues evaluated Los Angeles air quality measurements from three sources: NOAA-led research campaigns in 2002 and 2010, which involved extensive aircraft sampling of the atmosphere; datasets from other intensive field campaigns reaching back five decades; and air quality measurements from the California Air Resources Board monitoring sites, which reach back two to three decades.
Overall, VOCs dropped by an average of 7.5 percent per year. “This is essentially the kind of change we would expect, and it is very good to find that it is actually taking place,” Warneke said.
A few specific VOCs, such as propane and ethane, did not drop as quickly. Those chemicals come from sources other than vehicles, such as the use and production of natural gas. Another recent study led by CIRES and NOAA researchers and published online August 4 in Geophysical Research Letters, also an AGU journal, has shown that one VOC, ethanol, is increasing in the atmosphere, consistent with its increasing use in transportation fuels.
Warneke said that he would expect the decrease in emissions of VOCs by cars to continue in Los Angeles, given that engine efficiency continues to improve and older, more polluting vehicles drop out of the fleet of all vehicles on the road."
"Authors:
Carsten Warneke, Joost A. de Gouw, John S. Holloway and Jeff Peischl: Chemical Sciences Division, NOAA/ESRL, Boulder, CO, USA, and Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, USA;
Thomas B. Ryerson: Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, USA;
Elliot Atlas: Marine and Atmospheric Chemistry, RSMAS/University of Miami, Miami, FL, USA;
Don Blake: Chemistry, University of California at Irvine, Irvine, CA, USA;
Michael Trainer and David D. Parrish: Chemical Sciences Division, NOAA/ESRL, Boulder, CO, USA."
Some of California's pollution will always be there because it comes from Asia:
7/20/2007, "Huge Dust Plumes From China Cause Changes in Climate," WSJ, Robert Lee Hotz
"On some days, almost a third of the air over Los Angeles and San Francisco can be traced directly to Asia. With it comes up to three-quarters of the black carbon particulate pollution that reaches the West Coast, Dr. Ramanathan and his colleagues recently reported in the Journal of Geophysical Research.
This transcontinental pollution is part of a growing global traffic in dust and aerosol particles made worse by drought and deforestation, said Steven Cliff, who studies the problem at the University of California at Davis.
Aerosols -- airborne microscopic particles -- are produced naturally every time a breeze catches sea salt from ocean spray, or a volcano erupts, or a forest burns, or a windstorm kicks up dust, for example. They also are released in exhaust fumes, factory vapors and coal-fired power plant emissions....
Asia is the world's largest source of aerosols, man-made and natural. Every spring and summer, storms whip up silt from the Gobi desert of Mongolia and the hardpan of the Taklamakan desert of western China, where, for centuries, dust has shaped a way of life."...--------------------------------------------------------
Ozone will always be in California because a lot of it comes from Communist China:
April 2011, "Air Pollution in China, Facts and Details," Jeffrey Hays
"The Japanese professor Fumitaka Yanagisawa said that when he presented a paper at a Chinese university that suggested some pollution in Japan originated in China he was booed by the audience and said “even now it’s sort of taboo to mention cross-border pollution when I’m invited to give a speech in China.” Reiko Sodeno, of the Japanese environmental ministry, told AFP, “It will have adverse affects if we push China too much on cross-border pollution...Blaming other countries wouldn’t help to solve the problem, as it only hurts national pride.”"...(see sub-heading, 'Chinese air pollution goes abroad')
"Soot, dust and chemical pollutants from China have been captured in a weather observation stations on the summit of Mount Bachelor in Cascade Range in Oregon. Soot, dust, ozone and nitrous oxides can be detected by satellites moving across the Pacific." (see sub-head, 'Chinese air pollution reaches the United States')
"Electricity prices in China are half of those in developed countries."...(under sub-head, 'Cleaning up air pollution in China').
"Even if China increased the efficiency of its coal burning power plants, it wouldn't make much of difference because so many small industries and households burn coal for heating, cooking and power."...(sub-head, 'Success and limitations in cleaning up air pollution in China')."...
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8/26/2007, "As China Roars, Pollution Reaches Deadly Extremes," NY Times, J. Kahn, J. Yardley
"(Communist Chinese) Provincial officials, who enjoy substantial autonomy, often ignore environmental edicts, helping to reopen mines or factories closed by central authorities. Over all, enforcement is often tinged with corruption. This spring, officials in Yunnan Province in southern China beautified Laoshou Mountain, which had been used as a quarry, by spraying green paint over acres of rock. (p. 2 of 6) ...
Beijing also insists that it will accept no mandatory limits on its carbon dioxide emissions, which would almost certainly reduce its industrial growth. It argues that rich countries caused global warming and should find a way to solve it without impinging on China’s development....(p. 2 of 6)"Senior leaders are either too timid to enforce their orders, or the fast-growth political culture they preside over is too entrenched to heed them....
China cannot go green, in other words, without political change....(p. 5 of 6, bottom)
"Today, a culture of collusion between government and business has made all but the most pro-growth government policies hard to enforce."...(p. 6 of 6. 2nd para.)
"Officials have rejected proposals to introduce surcharges on electricity and coal to reflect the true cost to the environment. The state still controls the price of fuel oil, including gasoline, subsidizing the cost of driving. (p. 6)
"Energy and environmental officials have little influence in the bureaucracy. The environmental agency still has only about 200 full-time employees, compared with
18,000 at the Environmental Protection Agency in the United States. "...
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via Tom Nelson
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