Gas has long been touted as cleaner than coal and marketed as a "transition" fuel until the mass take-up of renewable energy becomes viable.
But a growing chorus of voices from Australia and overseas is warning that any perceived benefits could easily be lost with just small leakages.
Professor Peter Rayner from the University of Melbourne says it takes just 1-2 per cent of gas leakage for any advantage to be lost.
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| Queensland's coal seam gas industry now has more than 7000 wells. Photo: Saah Moles, Wilderness Society |
US regulators this year lifted their estimate of America's annual emissions of methane – the potent gas that makes up most of natural gas – by 13 per cent with leakage from the oil and gas industry largely blamed.
While methane clouds have been detected near gasfields, it took a huge leak starting last October from a gas storage site near Los Angeles to grab media attention.
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| CSG has its protesters now – before fugitive emissions are known. Photo: Andrew Quilty |
While Australia's gas boom, particularly for coal seam gas, is of a much smaller scale than the US shale bonanza, many of the issues are identical. These include the lack of baseline studies to distinguish the impacts of drilling and fracking of wells from natural methane seepage.
Closer to the surface
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| The industry says just 0.02 per cent of the gas developed vents as methane to the atmosphere. Photo: Glenn Hunt |
"It's closer to the surface [than conventional gas] ... it's more dispersed, and the chances for something to go wrong are much higher," he said.
CSG operators such as Santos, Origin Energy and BG Group, say they have every incentive to limit leakage of the lucrative commodity from their lattice of CSG wells and pipelines.
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| LNG exports were worth $16.9 billion in 2014-15, APPEA says. Photo: Stephanie Kelly |
"Santos meets all its regulatory requirements around emissions," a spokesman said. "We monitor, independently audit and make this data publically available in our annual Sustainability Report."
But a spokesman for Queensland's Department of Environment and Heritage Protection conceded that Santos's EIS "does not include provisions for a formal auditing process". However, the proponent is required "to document its proposed operations and how these will impact on the environment, which the department uses to "to inform the relevant permit conditions and requirements".
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| Chinchilla community members said the Condamine River has never bubbled with such frequency before CGS mining came to the region. Photo: Max Phillips |
Migratory emissions
Researchers, though, say little is understood about how drilling and fracking may create conditions for leakage through the soil long after a well has been decommissioned.
With more than 7000 CSG wells in Australia and headed towards tens of thousands, "the long-term, post-production fugitive [emissions] are certainly a sleeper issue," Professor Rayner said.
Dimitri Lafleur, a former geoscientist at energy giant Shell, said the industry has little idea of how much "migratory emissions" are making it to the surface.
"With such a vast network and thousands of wells, it is very difficult to come up with an accurate number if you don't monitor on a regular basis," said Mr Lafleur, a PhD student at Melbourne University under Professor Rayner.
"And given it is not a requirement to minimise fugitive emissions, why would you?"
Mr Lafleur is part of a team commissioned by The Australia Institute to examine how big a problem such leakage is and how it might affect Australia's national emissions targets given the industry's rapid expansion.
"No one knows what the baseline emissions are – from natural emissions from seeps, bores, for example – but I believe there is a chance that these emissions will become larger, with continued water extraction," he said. Companies remove huge amounts of water to get to the gas, depressurising the aquifers in the process.
'Social licence issue'
Political opposition to CSG has come mostly from the Greens. Labor and the Coalition generally back developments in Queensland, but have mixed views of the sector in other states such as Victoria and NSW.
NSW Greens MP Jeremy Buckingham became an internet sensation when he set the Condamine River in Queensland alight in April. Deputy Greens leader Larissa Waters, along with independent senator Gleenn Lazaus, has helped lead senate inquiries into CSG.
"Coal seam gas and fracking wells and pipes leak like a sieve, and they could be just as bad for the climate as burning coal," Greens Senator Larissa Waters said.
"As disused gas wells age and concrete casings break down, we risk further leaks for decades to come," she said. "No studies have systematically examined the deteriorations of old wells."
Fairfax Media sought comment from Environment Minister Greg Hunt and his Labor counterpart, Mark Butler.
Gas produces as much as 77 per cent more energy per molecule of CO2 than coal.
Professor Rayner said emissions issues with CSG had the potential to diminish public support for an industry already dogged with problems such as salt disposal, access to farmers' lands and interference with ground water.
If CSG is not cleaner than coal, "the whole social licence issue is brought into question," Professor Rayner said. "It becomes quite serious."
'Rivers shouldn't do that'
Locals say the bubbling of the Condamine River, which was highlighted when Greens MP Jeremy Buckingham set fire to it on Friday, is caused by a nearby CSG operation.
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