A new study by a Cornell University ecologist and expert on methane argues that "natural gas is a bridge to nowhere" in terms of arresting climate destabilization.
Robert W. Howarth, an Earth systems scientist and biogeochemist, also contends that replacing diesel engines with those running on liquefied natural gas, as proposed by the government of British Columbia, is a bad idea due to energy inefficiencies and methane leakage.
Moreover, his study finds the push to use more natural gas to heat homes and water may be wrongheaded because natural gas is "not a climate friendly fuel for these uses."
"The use of fossil fuels is the major cause of greenhouse gas emissions, and any genuine effort to reduce emissions must begin with fossil fuels," his study concludes.
The new study, an update on a controversial 2011 paper, contradicts the basis for the B.C. government's much-hyped liquefied natural gas strategy.
The B.C. government argues that natural gas is the "world's cleanest-burning fossil fuel," and that provincial exports of LNG "can significantly lower global greenhouse gas emissions by replacing coal-fired power plants and oil-based transportation fuels with a much cleaner alternative."
But Howarth squarely challenges these claims by arguing that the greenhouse gas footprint of methane is so large in the short term, with leakage from natural gas extraction so significant, that ultimately "natural gas is a bridge to nowhere."
A potent atmospheric warmer
Citing a flurry of recent methane leakage studies, Howarth's report argues that natural gas found in shale formations, which requires hydraulic fracturing to extract, leaks and vents about 50 per cent more methane during production than conventional drilling. (In the Bakken oil fields alone, industry dumps into the atmosphere nearly $100-million worth of methane a month because it can't be bothered to conserve gas associated with oil production.)
In addition, methane is a much more potent atmospheric warmer than carbon dioxide in the short term.
Methane, which is 21 times more potent than CO2 and takes about 12 years to dissipate in the atmosphere, accounts for nearly 40 per cent of global atmospheric warming.
Even if society eliminated CO2 emissions tomorrow but ignored methane, Howarth argues the planet would still warm to the dangerous 1.5 to 2 degree Celsius threshold within 15 to 35 years.
"By reducing methane emissions, society buys some critical decades of lower temperatures," his study says.
To properly evaluate the role of methane and the greenhouse gas footprint of the shale gas industry, a government needs to measure four things, the ecologist says.
It must calculate the amount of CO2 emissions from energy burned to mine shale gas; accurately tally the real leakage methane rate from the natural gas system; estimate the global warming potential of methane in the short term, and figure out how efficiently methane is now burned for energy.
Little of this accounting has been yet done by the B.C. government, an advocate for the LNG industry.
Recent studies show that U.S. methane leakage from the natural gas industry is likely greater than the 1.8 per cent assumed by the U.S. Environmental Protection Agency and could range anywhere between 3.6 and 7.1 per cent.
The B.C. government estimates that its natural gas fields leak about 0.3 per cent of production to atmosphere, but critics, including Howarth, argue that this number, among the lowest ever published by the industry, is not based on real measurements in the field.
A study partly funded by the BC Oil and Gas Commission and published by the U.S. Environmental Protection Agency in 2004 found, for example, a startling discrepancy between estimated and real methane leaks reported by natural gas plants.
In addition, recent U.S. studies have found leakage rates of four per cent in an unconventional gas field in Colorado, and nine per cent in a Utah shale gas field. Most of BC's natural gas comes from unconventional fields requiring extensive hydraulic fracturing.
Diesel-to-natural gas transition makes no sense: Howarth
Natural gas only has a lower footprint than coal in energy systems where the methane leakage rate from wells, pipelines, gas plants and infrastructure is 3.2 per cent or less.
By Howarth's calculations, it makes no sense to use natural gas to replace "diesel fuel as a long-distance transportation fuel" because it would greatly increase greenhouse emissions.
The B.C. government, which heavily subsidizes the shale gas industry with free water, geoscience services and low royalties, has proposed to replace diesel in heavy and medium vehicle fleet trucks with natural gas as well as build three new coastal ferries fueled by LNG.
Not only is the energy of natural gas used less efficiently than diesel in truck engines, but methane emissions and leaks from transportation systems have not been well quantified.
Howarth warns that there could be significant emissions during refuelling operations for buses and trucks, as well as from the venting of on-vehicle natural gas tanks to keep gas pressures significantly safe during warm weather.
His study concludes that "using natural gas rather than coal to generate electricity might result in a very modest reduction in total greenhouse gas emissions," but only "if those emissions can be kept below a range of 2.4 to 3.2 per cent."
BC minister briefed on methane
Opinion varies on the significance of the methane leakage problem.
Fred Krupp, president of the Environmental Defense Fund, and former New York City mayor Michael Bloomberg recently argued in the New York Times that methane seepage issue was "essentially a data acquisition and management problem -- the kind that we know we can solve" with better monitoring and tougher regulations.
Others, such members of the shale gas industry, have accused Howarth of bogus science and "saying outrageously silly things like burning natural gas is worse for the environment than burning coal."
The scientist's new paper echoes warnings in briefing notes recently presented to B.C. Environment Minister Mary Polak.
The notes, obtained by Canadian Press, warn that "methane emissions are a particular concern since they have a global warming impact 21 times higher than carbon dioxide."
"A small increase in the percentage of natural gas that escapes can have a significant impact on overall emissions," one note said.
In related news, a study by the Oxford Institute for Energy Studies reported that companies such as Encana, Shell and Exxon, which banked heavily on making money from shale gas, have declared a total of $35 billion in write-offs due to low natural gas prices and high drilling costs.
The reasons from the write-offs include the constant need to need to drill and acquire leases due to rapid depletion rates, "infrastructure needs, transportation costs, increasing costs to manage environmental considerations as operations grow, and importantly, the fact that drilling and hydraulic fracturing costs respond to fluctuations in gas and oil prices as well as demand, leaving little excess profit for long."