By Chris Johansen
Methane is the main focus of climate campaigners in Western Australia, particularly with the W.A. government’s promise to phase out coal-fired power by 2030. Methane is a greenhouse gas that is around 85 times more potent than carbon dioxide over a 20 year timespan.
This is the time left to reach net zero emissions globally in order to avoid catastrophic climate change. In 2021, global atmospheric methane concentration was 1.9 ppm, or around 162% greater than pre-industrial levels.
The current atmospheric carbon dioxide concentration is around 415 ppm, a 218 times greater concentration than methane. However, due to the greater potency of methane, this greenhouse gas contributes about one-third as much to global warming as does carbon dioxide.
About 40% of methane emissions come from natural sources such as wetlands, while 60% come from anthropogenic sources such as cattle, sheep and other ruminant farming, fugitive emissions from fossil fuel extraction and processing and organic material decomposition in landfill sites.
Regular atmospheric methane monitoring by the US National Oceanic and Atmospheric Administration has indicated that, although methane emissions appeared to be levelling off during 2000 to 2007, they have been rapidly increasing since then, threatening a blow-out of global greenhouse gas levels.
Methane emission rates remained unabated even during the previous two years when the global Covid pandemic slowed down industrial activity.
Recent research has elucidated why this is so. There are three main reasons:
- Over the last decade there has been an expansion of exploration, extraction and processing of natural gas, and thus consequent increased fugitive emissions of methane. In particular, gas fracking activity has multiplied, with its particularly high levels of fugitive emissions.
- The warming planet has increased rate of methane release from melting permafrost in the Arctic and in wetlands across the world. Rising temperatures stimulate activity of methanogenic microorganisms in melting permafrost and wetlands.
- With the increase in wildfires globally due to global warming more carbon monoxide goes into the atmosphere. Carbon monoxide reacts with hydroxyl radicals, which normally react with methane to remove it from the atmosphere. Thus there are less hydroxyl radicals left in the atmosphere to react with methane and therefore methane is retained for longer, further accelerating global warming.
The authors of these studies have estimated that global heating is four times more influential in accelerating methane emissions than previously suspected.
Thus it is suggested that global heating has a “double edged sword” in terms of methane emissions – increasing methane release from permafrost and wetlands and preventing its breakdown once in the atmosphere. Hence a catalytic cascade towards accelerating global warming.
The recognition of the threat of methane as a major contributor to global warming was endorsed at COP26 in Glasgow last year. More than 100 countries signed a Global Methane Pledge, with the aim of cutting national methane emissions by 30% by 2030, compared with 2020.
However, several of the major methane emitting countries, including China, India, Russia and Australia, opted out of signing.
So, climate activists in Australia should have two main thrusts – advocating methane emissions reductions per se and inducing the Federal Government to sign the Global Methane Pledge.
Activists in Western Australia have a particular responsibility, as this is the only state with increasing greenhouse gas emissions, mainly due to methane, and it has plans to further expand natural gas extraction in the north west shelf and on land through fracking.
You can get involved with influencing W.A.s Enivronmental Protection Authority’s draft Greenhouse Gas Policy, a Guideline which outlines the assessment criteria for new and existing fossil fuel projects.
We need a rigorous new greenhouse gas policy based on the best climate science, which will drive strong and immediate action to bring down gas pollution and warming in our state.