Concerns are mounting that fugitive methane emissions from Australian energy production are being significantly underreported, which could hinder Australia’s ability to meet its emissions reduction targets and exacerbate the climatic impacts of increased greenhouse gas emissions.
Australia was responsible for 1.5 per cent of the 120 million tonnes of methane released into the atmosphere globally in 2023, according to the most recent data published by the International Energy Agency’s (IEA) Global Methane Tracker earlier this year.
It is estimated that methane accounts for about 30 per cent of Australia’s total greenhouse gas emissions.
Methane is produced at virtually every oil and gas project around the world, either as a by-product of oil production or directly from gas or gas condensate reservoirs.
Although the majority of methane produced is sold as natural gas, its direct emissions into the atmosphere significantly contribute to global warming.
The majority of methane emissions in Australia originate from the agricultural and natural gas industries, with fugitive emissions from oil and gas production estimated at approximately 6 per cent of the country’s total emissions, compared to 13 per cent globally.
Coal extraction is another source, where gas trapped within coal seams is released during mining activities.
The International Energy Agency (IEA) has previously suggested Australia was underreporting its fossil fuel sector methane emissions by about 60 per cent, with its estimate of 1,668 million tonnes of methane emitted in 2023 not matching the 1,007 million tonnes reported to the United Nations.
The IEA has also found that global methane emissions from the energy sector were about 70 per cent greater than officially reported by national governments.
These emissions include large-scale flaring and venting (where operators have no access to gas infrastructure and markets), but also routine methane losses from many small, undetected or unreported leaks across the oil and gas supply chain.
The scale of methane emissions worldwide was further confirmed earlier this year, with research by the Laboratory of Climate and Environmental Sciences in France quantifying the most abundant methane emissions released into the atmosphere by the global hydrocarbon sector.
Utilising thousands of satellite images captured over two years, the researchers mapped 1,800 methane plumes worldwide, with 1,200 of these attributed to hydrocarbon extraction.
The plumes were comparable in climate impact to 20 million cars being used over a year, and likely represented only about 10 per cent of actual emissions.
Importantly, the study demonstrated that the massive methane releases were not random and chaotic, but detected steadily above certain oil and gas extraction sites.
Recent analysis of historical satellite data dating back to July 2022 by the Open Methane project revealed that Australia’s official methane emissions data significantly underestimate methane levels near identified hotspots.
Founded and primarily funded by the renewable energy-focused not-for-profit The Superpower Institute, the Open Methane project combines satellite data with atmospheric modelling to create a scientifically robust framework for more accurate assessment of methane emissions.
Rather than validating official reporting, Open Methane’s results more closely aligned with an alternative dataset provided by Climate TRACE, which showed methane emissions were 2.5 times higher than the official statistics.
Atmospheric physicist Emeritus Professor Peter Rayner, Open Methane’s lead researcher and Science Lead at the Superpower Institute, noted the finding not only cast doubt on the accuracy of Australia’s self-reported methane estimates but also underscored the potential for significant underreporting of emissions.
Prof Rayner said: “The discrepancy between the official data from the National Inventory and the atmospheric measurements as observed by the Sentinel 5P satellite indicates a large uncertainty in current reporting methods.
“This suggests that policies based on these figures may be inefficient or ineffective in addressing methane’s impact on climate.”
He added that the initial results unequivocally showed the federal government needed to mandate measurement by industry operators, measuring actual emissions from specific locations instead of using averages based on decades-old industry data.
DETECTION METHODS ADVANCING
One of the tools used by the industry to detect methane leaks is optical gas imaging (OGI). With the advent of emerging technologies and new methods such as drones, remote sensors, and artificial intelligence, OGI can enhance a wide range of technical applications.
Other monitoring technologies include gas cloud imaging, drones that livestream data to sophisticated onboard sensors, augmented reality smart glasses for field operators, and handheld gas leak detectors.
OGI cameras leverage the absorbing nature of some types of molecules to visualise them within narrow spectral ranges, so that only gases absorbent in the infrared region can be detected.
One of the complications posed by OGI is the volume of footage and associated data produced by thermal cameras, creating a need for more sophisticated software and expanded processing capacity.
A potential solution is to implement automated inspections of oil and gas facilities using advanced leak detection technology. This approach would involve drones that could remotely identify methane leaks in real-time.
Drones and automation can significantly improve gas detection with thermal imaging by mitigating human error and the inexperience of surveyors.
