"(S)witching buses and trucks from traditional diesel fuel to natural gas could actually harm the planet’s climate," writes Coral Davenport on the findings of a new report written by Stanford University, the Massachusetts Institute of Technology and the Department of Energy’s National Renewable Energy Laboratory published Feb. 14 in the journal Science.
Although burning natural gas as a transportation fuel produces 30 percent less planet-warming carbon dioxide emissions than burning diesel, the drilling and production of natural gas can lead to leaks of methane, a greenhouse gas 30 times more potent than carbon dioxide. Those methane leaks negate the climate change benefits of using natural gas as a transportation fuel...
The study concludes that there is already about 50 percent more methane in the atmosphere than previously estimated by the Environmental Protection Agency, a signal that more methane is leaking from the natural gas production chain than previously thought.
Davenpost does not mention the air quality benefits of natural gas over diesel fuel, now considered a toxic pollutant, although her New York Times colleage, Andrew Revkin of the Dot Earth blog, does include a quote from one of the co-authors, Adam Brandt of Stanford University’s Precourt Institute for Energy.
“Fueling trucks and buses with natural gas may help local air quality and reduce oil imports, but it is not likely to reduce greenhouse gas emissions."
In addition to reduced air pollutants, other incentives for trucking companies to switch to Liquefied Natural Gas (LNG) include competitively priced fuel, as shown by this Feb. 12 article from the trucking magazine, Transport Topics, "C.R. England to Deploy LNG Tractors":
We believe natural gas is the best alternative fuel to diesel currently available for longhaul Class 8 trucks,” Chief Operating Officer Zach England said. “In addition to reducing emissions, we believe there is the potential to reduce fuel costs and operate trucks that run quieter than those using diesel.”
It will take many more natural gas-powered vehicles to create even a dent in the petroleum dominance of transportation fuels. "Natural gas will increase its share of road transport fuels to 2.5 percent in 2018 from 1.4 percent in 2010 as consumers look for cheaper, cleaner forms of propulsion, according to the International Energy Agency," [Bloomberg News, May 14, 2013].
If the coal industry was hoping to find some good news in the report's poor grade for natural gas, their hopes were dashed. "(T)he study does conclude that switching from coal-fired power plants — the nation’s largest source of carbon pollution — to natural gas-fired power plants will still lower planet-warming emissions over all. Natural gas emits just half the carbon pollution of coal, and even factoring in the increased pollution from methane leaks, natural gas-fired plants lead to less emissions than coal over 100 years, the study found," writes Davenport.
For motorists who opt for a natural gas-powered vehicle in California, the clean air benefits allow them access (with white sticker) to the carpool lane along with electric vehicles, "valid through January 1, 2019."