Early detection needed for gas export hubs

Santos’s major gas export hub in Darwin, NT, has been leaking large amounts of methane for nearly 20 years. It has been suggested that the leak could be draining out 184 kg of gas per hour. Experts say this leak should be urgently fixed as a government priority as it can directly affect climate change, and hubs should be monitored to detect leaks early.

“[The] report by the ABC on the Darwin LNG methane leak is extremely concerning. Methane is a powerful greenhouse gas, up to 80 times more powerful than carbon dioxide. While fugitive emissions (unintended leaks as part of processing and storage) are common, leaks of this scale and timespan represent a hidden driver of changing atmospheric chemistry and climate change,” said Dr Sean Bay, ARC DECRA Fellow in the School of Agriculture, Biomedicine, and Environment at La Trobe University.

“In our lab, we look at the biological processes that remove methane from the atmosphere. This process is driven by bacteria called methanotrophs, the only known biological methane sink. They live in the soil and on tree surfaces and remove approximately 30–40 Mt CH₄/year and 25–50 Mt CH₄/year respectively. Our most recent discovery shows that bacterial biofilms in caves are potentially an even bigger sink, removing up to ~100 Mt CH₄/year. However, this natural ecosystem service is finite, and we are only beginning to understand and model its role in mitigating or offsetting methane emissions from industry and agriculture. Industrial leaks of this scale risk overwhelming these natural sinks, erasing their climate benefit.

“We strongly believe that independent monitoring and public disclosure are essential. Today we have the technology, from satellites to sensitive ground-based detectors, to identify leaks early and act quickly. Methane is one of the most actionable levers to slow climate warming. Fixing leaks like this should be a top priority.”

Dr Martino Malerba is a Senior Lecturer and ARC DECRA Fellow in the Centre for Nature Positive Solutions at RMIT University. Malerba said investment in monitoring is urgently needed.

“Methane is one of the most dangerous greenhouse gases. We often call it the ‘low-hanging fruit’ of climate action because it is over 80 times more powerful than carbon dioxide at trapping heat in the atmosphere over a 20-year period,” Malerba said. “A single undetected leak can wipe out the climate gains made elsewhere. We urgently need to invest in better monitoring systems. Satellites are improving quickly and can now spot large plumes from space, but they still miss many smaller, long-lasting leaks. That is why onsite monitoring is essential.

“New technologies, such as the low-cost, solar-powered sensors, are now making continuous, real-time methane measurements possible. For example, my lab has created the Pondi to offer cost-effective and scalable real-time greenhouse gas monitoring at low cost. These systems give us the tools we need to detect leaks early and prevent avoidable climate damage.”

Image caption: LNG carrier in the Timor Sea with tugboat and view over Bicentennial Park in Darwin, NT. Credit: iStock.com/EAGiven