A world-first aerial survey of Queensland’s main coal seam gas (CSG) region has found methane emissions considerably higher than some previous reports.
- An international team of scientists mapped out methane emissions in Queensland’s Surat Basin
- The coal seam gas emissions were up to three times higher than some previous estimates
- Other emissions sources included cattle, water ponds and possibly abandoned wells
University of New South Wales Associate Professor Bryce Kelly — who helped co-ordinate the international research into Queensland’s Surat Basin region through the United Nations Environment Programme — described the survey’s findings.
“In terms of the coal seam gas sector, we are finding that emissions per unit of gas that’s produced is two to three times higher than has previously been estimated,” Dr Kelly told ABC’s 7.30.
“It’s really important that we measure methane accurately — the rate of methane is increasing [globally] at a record pace.
“Within our region of study, coal seam gas contributed about 30 per cent of the total emissions.”
The results of the study of the Surat Basin were published in the international scientific journal Philosophical Transactions of the Royal Society of London overnight.
It also concluded that previous methane estimates for feedlot and grazing cattle may need to be reviewed and that there was need for further studies.
“Some of the surprises were the extent of the emissions that were coming off raw-water ponds — and we went back to those raw-water ponds many times to validate our results and every time we drove around those ponds, there were substantial emissions coming off,” Dr Kelly told 7.30.
And there were other plumes of methane that could not be explained, but researchers suspect these came from abandoned exploration wells, natural seep or unaccounted-for human sources.
“So there’s a lot of work that still needs to be done to quantify all the methane emissions,” Dr Kelly said.
Emissions measured by device on plane
Previous inventories of methane emissions have involved so-called “bottom up” estimates, based on industry data and government records.
The researchers compared these results with a snapshot of atmospheric measurements taken from an aircraft that was fitted out with newer, precision technology.
They found methane emissions were roughly in line with Australia’s official reporting to the UN, but much higher than other inventories for the region.
“The atmosphere is the perfect record of greenhouse gas emissions — it’s our bank account,” Dr Kelly said.
“We are only flying 150 metres off the ground, so we’re getting the direct emissions going straight into the atmosphere as part of the survey.”
Fellow researcher and pilot, Professor Jorg Hacker, said the low-level captures were the only method that would give a reliable, totally independent measure of methane.
“If you want to reduce emissions, you have to first know what they are,” Professor Hacker said.
There will soon be greater transparency in global methane emissions, with the launch of a private satellite, MethaneSat, with plans to make all the data publicly available in 2023.
“It is a big game-changer,” Dr Hacker said. “We’re all looking forward to having MethaneSat up there monitoring 24 hours a day, seven days a week.”
Gas industry welcomes findings
The peak body for the CSG industry, the Australian Petroleum Production and Exploration Association (APPEA), said that, by world standards, Australian producers were relatively low emitters of methane.
However, APPEA chief executive Andrew McConville welcomed the survey’s findings.
“I think anything that improves the overall detection is a good thing,” Mr McConville said.
“Because that will help us do better, it will help agriculture do better, it will help all of those industries — mining — do better.”
Grazing cattle and feedlots accounted for half the methane emissions in the survey area.
Meat And Livestock Australia (MLA) has a policy of aiming for zero emissions by 2030.
MLA’s managing director, Jason Strong, also welcomed greater clarity in methane data.
“All of us have a responsibility to make sure that as we’re trying to solve the problem. We understand the problem as well as we possibly can,” Mr Strong said.
Meat producer NAPCo — which runs a feedlot in the Surat Basin — says it is making progress in reducing its methane footprint through breeding programs and changes to diet, making cattle burp less.
General manager James Carson said there had been “a lot of work” that had gone into feed supplements, through a product called red asparagopsis.
“Effectively that product … means that animals emit less methane,” Mr Carson said.
Dr Kelly said one of the aims of this research was to find obvious ways of restricting a potent greenhouse gas.
“Reducing methane going into the atmosphere is the most cost-effective way to reduce climate change today,” Dr Kelly said.
“Methane has a global warming potential, on a 20-year timeline, about 84 to 86 times greater than carbon dioxide.
“We don’t need major changes in technology. We don’t need to find places we can stick methane deep into the earth.
“We can solve these problems right now by simply mapping where everything is leaking and fixing it today.”
Watch this story tonight on 7.30 on ABC TV and iview.
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