"Forgotten Coal Well: Unattended Borehole Emitting Methane Equal to Over 10,000 Vehicles's Carbon Footprint"

In rural Queensland, Australia, a single abandoned coal exploration borehole has been identified as a "super-emitter" of methane, releasing approximately 235 tonnes of methane annually. This discovery, made by researchers from the University of Queensland using advanced LiDAR technology, sheds light on a previously unreported source of greenhouse gas emissions.

The borehole, which had been covered by dirt, was discovered due to a lack of grass growing around it. The researchers took methane emission readings from a borehole about 100 metres deep for a week, using a portable Quantum Gas LiDAR system that was more precise than standard handheld sensors.

Associate Professor Phil Hayes, from the University of Queensland's Gas & Energy Transition Research Centre, stated that this was the first long-term measurement of methane emissions from an abandoned coal exploration borehole. The findings were reported in the journal Science of the Total Environment.

Over 20 years, methane has had a warming effect on the planet that is 80 times stronger than carbon dioxide. Given this, experts are urging a complete audit to identify all leaking boreholes and quantify the extent of the unreported methane pollution. Thousands of old coal holes exist, and whether they are properly sealed or how much methane they might release is unknown.

Dr Sebastian Hoerning, one of the researchers, said, "While the majority of these boreholes won't be emitters, our measurements show they could be a major source of greenhouse gas emissions that is currently unreported." The team suggests that the quality of sealing by coal explorers in an estimated 130,000 boreholes in Queensland is unknown.

The researchers plan to expand their study to a larger number of boreholes, including water bores, to understand the full scope of the issue better and find more opportunities to reduce emissions. Sealing the worst emitters offers a straightforward, cost-effective way to reduce emissions, mostly with cement.

Climate experts believe that targeting methane offers a rapid way to curb global heating in the coming decades. This discovery underscores the importance of monitoring and addressing methane emissions from abandoned wells, particularly in regions like Queensland where regulatory requirements and monitoring obligations are currently lacking.

"Forgotten Coal Well: Unattended Borehole Emitting Methane Equal to Over 10,000 Vehicles's Carbon Footprint"