LISMORE, Australia, Nov. 21 (UPI) -- Australia's largest natural gas fracking operation is showing larger than expected leaks of methane, research conducted as part of a government inquiry found.
With fracturing of shale beds to release more natural gas becoming increasingly popular, releases of methane -- which has a greenhouse gas heating effect 25 time that of CO2 -- are a concern, the researchers said.
While most research on methane leaks has focused on wellheads, Damien Maher at Southern Cross University in Queensland and colleagues looked at gas seeping through the ground, NewScientist.com reported Wednesday.
Higher levels of methane were found in the air above the Tara gas field, site of Australia's most extensive fracking operation, suggesting widespread ground leaks, the researchers said.
Levels in some places were at 6.89 parts per million, more than three times the background level, they said.
The scientists said they suspect fracking is responsible for changes in soil structure, allowing more methane to escape.
"If it's leaking from the infrastructure that's an easy fix," study co-author Isaac Santos said. "If it's seeping from the soil that's much harder to fix."
The Australian Petroleum Production and Exploration Association, which operates the Tara gas field, disputed the findings, calling them "premature."
