Fracking the McArthur basin could release four to five times as much greenhouse gas emissions as the proposed Adani Carmichael mine, a leading researcher has said.
Tim Forcey, a chemical engineer with 30 years experience in the petrochemicals industry, appeared before a Northern Territory inquiry on Wednesday, also giving evidence that a gas shortage on the east coast was highly unlikely.
Forcey told the panel CO2-equivalent emissions from future fracking of the McArthur basin – or even just its gas-rich Beetaloo sub-basin – would dwarf those expected from the proposed Queensland coalmine.
“It’s very easy to get to numbers that are far bigger than everything you’d get if you burned all the coal that the Carmichael mine is talking about,” he told Guardian Australia outside the inquiry.
He also called for as great a focus on fugitive and other secondary emissions from extraction projects as there was on the main sources. Fugitive emissions are leaked directly into the atmosphere rather than being captured for burning to produce heat or energy.
The McArthur basin is estimated to hold 240tn cubic feet (6.8tn cubic metres) of shale gas. Citi market analysis has found there could be 100tn cubic feet (2.8tn cubic metres) in the Beetaloo sub-basin.
Forcey’s research – based on a fugitive methane emission rate of 5% – had calculated that 22bn tonnes of CO2-equivalent emissions could be released into the atmosphere if it was all extracted through fracking gas fields, equating to 22 years of Australia’s emissions. Once the gas was burned, it would contribute about 35bn tonnes.
Reports have put the Adani figure at about 7.7bn tonnes.
Origin energy has several tenements over the Beetaloo sub-basin, containing an estimated 6.6tn cubic feet (187bn cubic metres) of gas.
“The Beetaloo has the gas companies very excited but there are big questions to be asked about whether we should open ourselves up to a massive carbon pollution liability in the years to come,” said Forcey.
“This is a huge volume of hydrocarbons in the ground there and we are already facing a climate emergency. We’ve already produced too much greenhouse gases in the atmosphere. We have dangerous climate change today and we don’t need to produce any more.
“We’re blowing past carbon budgets at a great rate of knots so, yes, people should know … this is enormous ... This is one of the biggest gas fields in the world potentially.”
Forcey has previously produced research that revealed the coal seam gas industry could be vastly underestimating its emissions and was potentially producing twice the amount of emissions Australia promised to cut by 2030 as part of its Paris commitments.
In January a former senior compliance manager at Origin alleged the company had a deliberate policy of ignoring leaking coal seam gas wells and failed to properly measure the amount of gas it was producing. Origin denied the claims.
Forcey also said a gas supply shortfall in the eastern states was unlikely to occur, despite a shortage of “cheap gas”. Demand for gas peaked in 2012 and had fallen by 16% in 2016, he said, and was declining in every sector.
He said new gas sources, like those explored in the NT, were expensive to produce and domestic wholesale prices remained linked to international prices because it was now a seller’s market.
Forcey said his research showed “it’s now cheaper to go out and build a brand-new wind or solar facility and collect the electricity from that” than to continue running gas-fired electricity generators.
He questioned why the inquiry’s interim report didn’t examine the east coast market and the push for the NT to supply gas, given the national focus on it, but the inquiry chair, Justice Rachel Pepper, said it was outside the terms of reference.
The NT scientific inquiry into hydraulic fracturing is hearing from dozens of industry, community, scientific and environmental witnesses in order to prepare a report for the NT government, which will then decide to either lift or maintain its moratorium.
Inquiry panel member Prof Barry Hart noted community concerns about potential aquifer contamination and asked about remediation options.
Santos’ Geoff Atherton said the company was working on prevention instead.
“We don’t actually think there is a risk to contaminating the aquifer at all. We think we can drill through it and get it isolated before we drill ahead,” he told the inquiry.
“I think the first thing is, if we had evidence of some catastrophic leakage into a shallow aquifer, there are many natural mitigants – recharge, dilution, half-life deterioration and reduction of concentration, etc – we would monitor the spill, try and track the progress of a spill, and we would seek to perhaps deplete a small portion of the aquifer if it was a focused spill. If it’s not a small portion, we’re probably diluting very rapidly to where the hazard is mitigated.”
Bill Ovenden, Santos vice-president of exploration and appraisal, also told the inquiry the company would seek to treat sacred sites on a case-by-case basis, suggesting it would seek to make agreements with traditional owners, rather than through the statutory authority.
In response to questions about the importance of groundwater to many Indigenous sacred sites, Ovenden said the company would be open to the protection of subsurface environments as part of sacred sites surveys.