Co-author of the study, Dr Douglas Tait from Southern Cross University said, “This study clearly showed that there is something going on in these areas leading to increased atmospheric greenhouse gas concentrations.”
However fellow author Professor Isaac Santos, said, one of the major issues with attributing the elevated gas concentrations to coal seam gas mining is the lack of baseline studies.
“From our data we cannot conclusively say that the elevated concentrations are due to CSG mining activities as we have no information about the area before the commencement of CSG mining,” Professor Santos said.
The study’s lead author, Dr Damien Maher said there were some clues as to where the methane and carbon dioxide was coming from.
“The technology we used gives us additional information about the methane and carbon dioxide,” Dr Maher said. “We also measure the carbon stable isotope ratios of the gases, which is like a chemical fingerprint. This gives us insight into where the gases came from and how they were formed. This is a very powerful tool which enables us to model what the source of these gases might be, which is important in areas where there are a number of potential sources. For example in the Darling Downs the methane and carbon dioxide can be coming from sources other than CSG such as wetlands, feedlots and vehicles”
“The methane in the atmosphere of the Darling Downs gas field has a very similar fingerprint to methane in the CSG of the region,” said Dr Maher. “A portion of the carbon dioxide appears to be coming from the expansive water holding ponds, which was something that surprised us.”
The researchers agree that this is only a first step in determining the greenhouse gas footprint of the CSG industry in Australia
“While we know that there are some leakages happening in the studied CSG field, we do not know the magnitude of these leakages, nor do we know if this is a consistent trend across all CSG fields in Australia, these are areas of research we are actively pursuing,” said Dr Tait.
The study titled ‘Mapping methane and carbon dioxide concentrations and ?13C values in the atmosphere of two Australian coal seam gas fields’ the first peer-reviewed paper on atmospheric methane and carbon dioxide concentrations in Australian coal seam gas (CSG) fields.
The paper’s authors are scientists from Southern Cross University: Dr Damien Maher, Professor Isaac Santos and Dr Douglas Tait from the Centre for Coastal Biogeochemistry Research in the School of Environment, Science and Engineering.
The researchers used novel instrumentation to map atmospheric methane and carbon dioxide concentrations in and around coal seam gas fields in the Darling Downs and northern New South Wales.
“CSG is often assumed to be a cleaner fuel than coal in terms of greenhouse gas footprint,” said Professor Santos. “However, if methane is being lost to the atmosphere during the extraction, processing and transportation processes, this assumption may not be valid.
“This is due to the potency of methane as a greenhouse gas, which is about 100 times more powerful than carbon dioxide over a 20-year time frame.”