Australia’s coal mine fugitive emissions have come under intense international scrutiny over the past couple of years, as monitoring technologies have revolutionised methane detection.
Today, there are public and philanthropically funded satellites flying overhead, picking up methane hotspots, even as we sleep. Over the last financial year, CarbonMapper’s Tanager-1 satellite has picked up 91 different methane hotspots across Australia. Half of those were in the Hunter Valley.
At the same time, Australian researchers have become global experts in aerial surveys, drone monitoring, and literal scientific drive-bys.
Earlier this year, a team of Australian scientists published the results of an extensive fly-over monitoring study over the Bowen Basin, alongside colleagues from Germany, the Netherlands, France, the US and the UK. The NSW EPA is currently piloting a network of stationary greenhouse gas monitors across the Hunter valley.
Thanks to the rapid advancements in this field, technologies are also becoming far more mobile. You can now fit incredibly powerful measurement technologies (like mid-infrared dual-comb spectroscopy) in the back of a car, and in June, APA trialled using drones equipped with gas-mapping LiDAR for methane detection at their Dandenong LNG facility.
These kinds of trials were simply not feasible a decade ago. And while each technology comes with its own uncertainties and analytical challenges, it’s clear that we don’t need to rely on a one-size-fits-all approach any longer.
It’s also clear that the age of borehole sampling, testing and simply estimating the emissions at open cut mines, should well and truly be past us.
This was one of the major findings from the Climate Change Authority’s 2023 review into methane measurement. The report recommended wholesale reviews into how methane is currently measured, “simple emissions factors do not adequately capture temporal or spatial specificity or variability” at open-cut coal mines.
These findings spurred on two parallel processes going on right now. The first, is a departmental review of how we currently estimate emissions from open-cut coal mines. The second, is the Expert Panel on Atmospheric Measurement of Fugitive Methane Emissions.
But after releasing their interim report this week, I’m worried that the panel’s focus has shifted from how we can leverage these rapidly improving technologies, to whether or not they will fit into a clunky, regulatory box.
So far, the panel has recognised that our current measurement approach just doesn’t cut it. They recognise that our existing approach fails to incorporate methane emissions from things like lateral gas migration or spoil piles. It can’t estimate emissions from below the pit floor, or even begin to estimate emissions from water management ponds.
They also recognise that in any coal mine, as you would expect, emissions are temporal. They note that our current approach simply fails to account for “episodic emission plumes” that you’d expect from drilling and blasting, changes in production, and even daily and seasonal atmospheric changes.
These are all sources of variability that could be far better accounted for through an integrated suite of aerial and stationary measurements, to supplement our current sampling approaches.
However, for all these clear and present reasons for reform, the panel’s interim review reads as if it’s being hamstrung by the regulatory box it’s trying to fit into.
Rather than a process of creative discovery that builds on the panel’s expertise, to design a new, integrated methane measurement system, each individual technology is currently being evaluated by a single criteria; “whether any given top-down approach can meet NGER scheme requirements.”
In fact, new measurement approaches are improving so much, they are apparently making the panel’s job even harder. The report notes that as algorithms are “customised and improved” and “sensors are being deployed in new ways,” that this “constant evolution” actually “diminishes the ability for the panel to interrogate” each approach’s performance.
Rather than imagining each technology within an integrated and diverse suite of solutions, they are each judged against individual regulatory limitations. This is a classic case of letting the perfect be the enemy of the good.
The interim report concludes that “the technical evidence does not yet support satellite data as a stand-alone basis for facility-level regulatory reporting.”
But if each technology is going to be assessed as a “stand-alone” replacement, then they’re not only under-utilising the incredible creative expertise within the panel, they’re just setting themselves up for failure.
Of course each technology has its limitations. Technologies that are known to be great at detecting episodic emission plumes, are likely less good at detecting diffuse, lower-volume sources.
But when each individual technology is viewed through the narrow lens of its ability to provide a one-size-fits-all solution to what the “NGER scheme requires”, the panel risks missing out on a clear and present improvement, while it tries to fit a technological revolution into an inflexible regulatory box.
