Growth in Australian open-cut coalmining raises urgency of methane abatement

More needs to be done to incentivise methane abatement projects for open-cuts, to ensure that the runaway growth of large open-pit mines in Australia does not put emissions reduction targets beyond reach.

Methane (CH4) is best known as a fuel – as natural gas or ‘fossil gas’ – but when it leaks into the atmosphere it is a potent greenhouse gas, with a higher warming effect than carbon dioxide (CO2). Controlling it is seen as one of the quickest ways to reduce global warming, and Australia has joined more than 120 other countries in signing the Global Methane Pledge to collectively reduce methane emissions by at least 30% from 2020 levels by 2030.

Methane emissions occur in coalmining operations because coal seams are also reservoirs for methane gas – which leaks out before, during and after mining.

According to Ember’s 2022 report Tackling Australia’s Coal Mine Methane Problem, “independent satellite measurements have uncovered underreporting of methane emissions from Australian coal mines – twice as high as official estimates”. The report also prioritised actions to capture emissions from underground coalmines as the largest immediate opportunity.

However, data published in late 2023 by Global Energy Monitor (GEM) in the Global Methane Emitters Tracker (GMET) indicated that there is more to consider for Australia. Australia is the world’s fourth largest coalmine methane emitter, yet it operates 75% of its coalmining by purely open-cut, or surface, methods; only 16% comes from purely underground mines. Therefore, while underground mines may be the most emissions-intensive, achieving meaningful change will require action on open-cut mines as well.

Varying methane emissions intensity of New South Wales (NSW) and Queensland (QLD) mines

Source: GEM Global Coal Mine Tracker Oct 2023. IEEFA Analysis.
Gas Content is Coalmine Methane Emissions Estimate (cubic metres per coal tonne).

Open-cut coalmining dominates Australia’s methane emissions

Open-cut mines in Australia are responsible for 52% of the methane emissions in Australian coalmining, and up to 60% when including the operations that combine open-cut and underground mining, according to the GEM data. A breakdown by state illustrates the key sources of emissions.