2026-06-30
LNG is really of no help in transitioning out of coal
By Chris Johansen, Green Issue Co-editor
The WA and Australian Governments argue that Australia’s exports of liquified natural gas (LNG) to Asian countries is helping them exit coal and thus reduce their greenhouse gas (GHG) pollution. This parrots the claim of the LNG exporters and the fossil fuel lobby in general.
This claim that conversion from coal-fired to gas-fired electricity generation reduces GHG emissions is based on just one metric, conveniently cherry picked. That metric is that burning of natural gas releases 50-60% less CO2 per unit of energy produced than the burning of coal. This metric is not disputed but there are additional metrics that need to be factored in when considering the entire LNG supply chain, and thus the LNG GHG emissions total footprint. These are fugitive emissions, manufacture of LNG and its transport overseas.
Fugitive emissions
The extraction of natural gas requires venting (direct release of some extracted gas into the atmosphere) and flaring (igniting the vented gas). This is for the purpose of regulating gas pressure during extraction and release of potentially explosive or other unwanted gases. According to Australia’s National Greenhouse Gas Inventory such fugitive emissions from oil and gas extraction (but mainly gas as little oil is now extracted in Australia) amount to 20-25 Mt CO2-e per annum over recent years. Total fugitive emissions recorded in Australia, including those from coal mines, amount to about 50 Mt CO2-e per annum, which is about 10% of Australia’s total recorded GHG emissions.
Another source of direct release of extracted natural gas, primarily methane, into the atmosphere is via leakage from pipes and storage tanks between the well head and the LNG processing plant. This is notoriously difficult to quantify as such leaks occur intermittently and are usually not identified until well after they have occurred. But whatever methane is detected, the wrong conversion factor as to its potency is still officially used. The Australian Government uses a Global Warming Potential (GWP) factor – a measure of how much a given mass of a GHG contributes to global warming over a specified time period compared to CO₂ ‒ for methane of 28, using a 100 year time scale. However, much more relevant to the reality of climate change we are now facing is the 20 year time scale, for which the GWP is 80-84 – rendering methane as three times as potent as officially reported. Methane released in venting is also assessed with a GWP of 28.
In Australia at least, fossil fuel extractors are required to self-report their fugitive emissions. Commercial enterprises are not likely to over-report their emissions of waste products, with a more likely tendency to the contrary. As I understand there is no independent, rigorous verification in Australia of what is reported. Evidence that methane emissions are indeed globally underreported comes from satellites able to increasingly accurately detect methane emissions at ground level.
Manufacturing LNG
Converting extracted natural gas to LNG is an energy intensive process. Several steps are involved. Initially purification – removal of free liquids, solid particles, water vapour, CO₂, H₂S, mercury, and heavier hydrocarbons like ethane, propane, and butane. Then liquification, involving cooling to -162°C requiring highly energy intensive refrigeration. According to a recent US study by Robert Howarth, liquefaction processes contribute 8-9% of the total LNG emissions footprint.
Transport and regasification
And yet more metrics. The fuel used, mainly heavy fuel oil or diesel, in ships to transport LNG from Australia to destination countries in East Asia further adds to the LNG emissions footprint. Of course, the extent of emissions from tanker fuel and from energy required to keep LNG tanks super-cooled would depend on the length of the voyage. According to Howarth, this can contribute 4-8% of the footprint. Further, the regasification of LNG requires energy and some emissions would result in moving the methane gas to its final destination for combustion.
LNG vs coal
Howarth’s US study estimates that the GHG footprint for LNG as a fuel source is of the order of one-third greater than that for domestically burned coal when analysed using GWP on a 20 year basis. But of course this would vary with the specific export operation, depending on extent of fugitive emissions, liquefaction efficiency, transport duration, etc. I’m unaware of any similar such detailed studies in Australia, which would in any case would be difficult to achieve due to major uncertainties about fugitive emissions and lack of public access to LNG production and transport data. However, from data elsewhere it would be difficult to conceive that burning of natural gas via the LNG process would be any less GHG polluting than coal. If claimed that it is then the proponent should be asked as to what their estimates for fugitive emissions and emissions from manufacturing and transport of LNG are.
A transition fuel then?
Contrary to government and industry claims, the above analysis does not support the contention that LNG is less GHG polluting than coal. Indeed it suggests that there would be less GHG pollution if existing coal plants were allowed to continue functioning, or even new ones built.
Governments and industry claim that their LNG exports are replacing coal in East Asia but no evidence for that is provided. Like in Australia, coal plants are usually allowed to serve out their originally intended life span, or are even renovated to extend life. When a coal plant does close, if its energy production is not completely replaced by renewable energy, it is usually replaced by a gas fired power station because that is cheaper to build and more flexible in meeting variable grid demand than a coal plant.
What LNG export to Asia is likely to be doing is not replacing coal but slowing the conversion to renewable energy.
Then there is the argument that most of the emissions from LNG export occur outside Australia, in shipping and when the gas is eventually burnt, that is Scope 3 emissions. The corollary being that they are beyond Australia’s control and that the country is therefore not accountable for them. The good ol’ “drug dealers defence” – I only supply and am not responsible for what the buyer does with the product. However, as Australia is a country particularly vulnerable to climate change, the worry should be about release of GHG per se, wherever in the world they are released.
Conclusion
LNG export to Asia is exacerbating global GHG emissions rather than helping to abate them. Methane is a particularly potent GHG and its global release is accelerating, encouraged by the ambitions of the gas extraction industry. If any government is serious about combating climate change then they should be taking steps to phase out the release of fossil methane. Australia has joined the Global Methane Pledge ‒ to reduce global methane emissions across all sectors by at least 30% below 2020 levels by 2030. The gung ho attitude of Australian governments to gas extraction and LNG export does not augur well for living up to this pledge.
Header Photo: Woodside’s Burrup Hub Credit: Australian Conservation Foundation, Josh Meadows March 2024
[Opinions expressed are those of the author and not official policy of Greens WA]