Tut tut... On the other hand:
... The study, by the Harvard Center for Risk Analysis (HCRA) at Harvard School of Public Health, found, among other things, that natural gas (LPG) reduces emissions of fine particulates, those smaller than 2.5 microns, but may generate more ultrafine particles than diesel, of less than 0.1 micron. "Several studies indicate that ultrafine particles may have an even more dramatic impact on health than those in the fine category." It also found that LPG would increase greenhouse gas emissions, of C02, and of methane, which "is approximately 20 times more potent as a greenhouse gas than CO2". http://www.hsph.harvard.edu/press/releases/press1102000.html Full report (PDF, 205 KB): http://www.hsph.harvard.edu/Organizations/hcra/diesel/diesel.pdf http://www.planetark.org/dailynewsstory.cfm/newsid/18503/story.htm Smelliest trucks in US begin to belch cleaner USA: November 8, 2002 NEW YORK - They rumble through the neighborhood at dawn, smell bad and are hard to drive past. But U.S. garbage trucks are becoming friendlier as the clouds of black diesel smoke they belch are slowly becoming a thing of the past, a green group said this week. The 179,000 garbage trucks in the United States consume 24 million barrels of diesel fuel annually, according to INFORM, a New York-based environmental group. Trash trucks are the least fuel-efficient vehicles on the road, averaging 2.8 miles per gallon, the group said in a report. The report, called Greening Garbage Trucks, surveyed 25 U.S. cities including New York, Los Angeles and Washington, D.C. It found that 90 percent of garbage trucks are powered by diesel fuel, but that the rest of the vehicles have converted to cleaner natural gas and liquefied natural gas (LNG). The gas-fueled trucks emit 70 percent to 90 percent less particulate matter than diesel, 30 percent to 70 percent less of acid rain component nitrogen oxide, and 10 percent less carbon dioxide, a greenhouse gas thought by scientists to cause global warming by trapping the sun's heat in the Earth's atmosphere. In California the South Coast Air Management District mandates that townships replace diesel trucks with natural gas and NGL trucks as the conventional trucks retire. David Rodriguez, the fleet manager for the city of Santa Monica, California, said nearly all of the city's 22 garbage trucks have already been converted to run on natural gas and are equipped with John Deere "81" engines. "They are holding up very very well," said Rodriguez when asked how the trucks perform versus conventional engines. FROM ROTTING GARBAGE TO FUELING TRUCKS The savings in greenhouse gas reductions of gas-fueled trucks has also helped Waste Management Inc. , the leading U.S. garbage hauler, garner greenhouse gas reduction credits. In turn, that helps it buy more green trucks. Under the California mandate, utility PG&E Corp. has helped Waste Management pay for the conversion of trucks to run on natural gas and LNG. Waste Management's "supply" of emissions reductions allowed it to sell credits to a companies that needed to buy the right to emit greenhouse gases. PG&E bought the credits to offset emissions of a power plant the company was building in San Diego county. Waste Management also siphons off potent greenhouse gas methane formed from rotting garbage at its landfills, which also helps the company get emissions credits. One day the methane may also fuel garbage trucks. "Because we collect all this methane gas, we're trying to look into how do you convert methane gas from our landfills into LNG gas for our trucks," said Sarah Simpson, a Waste Management spokeswoman. "It's something we think has a lot of potential," she added. Story by Timothy Gardner REUTERS NEWS SERVICE ------------------------ Yahoo! Groups Sponsor ---------------------~--> Sell a Home for Top $ http://us.click.yahoo.com/RrPZMC/jTmEAA/jd3IAA/9bTolB/TM ---------------------------------------------------------------------~-> Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html Biofuel at WebConX http://webconx.green-trust.org/2000/biofuel/biofuel.htm List messages are archived at the Info-Archive at NNYTech: http://archive.nnytech.net/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
