Action in agriculture and the oil and gas industry could produce rapid reductions in the powerful greenhouse gas methane.
25% of Scotland’s contribution to climate change in 2021 was due to our emissions of methane. Because methane is around 80 more powerful at causing climate change than carbon dioxide in the short term, action to reduce methane emissions can bring about rapid reductions in overall climate impact.
Emissions in Scotland come from agriculture, the waste and energy sectors and degraded land. Emissions from the waste sector have fallen by nearly 80% since 1990, mainly because we have captured the methane generated by rotting waste in landfill sites, using it to make energy or heat. Emissions from the energy sector have fallen more than 80%, mainly because of the decline and disappearance of coal mining. Meanwhile emissions from the agriculture system sector have fallen less than 15%, this reduction mainly coming from the reduction in cattle and sheep numbers. Methane emissions from Scotland’s land have increased since 1990, largely because of damaged peatlands.
The largest source in Scotland is agriculture, responsible for 45% of methane emissions. Better manure management and selective breeding of livestock could reduce these emissions, as well as a widespread switch in people’s diets to reduce meat and dairy consumption.
Emissions from the energy sector come mostly from deliberate venting or leakage of gas during production, processing and transport of both oil and gas.
A new report from the International Energy Agency shows that methane emissions from the global energy sector remain at near-record levels.
While some governments have taken on commitments to reduce methane emissions, these emissions need to be cut by 75% by 2030 if the global temperature increase is to be limited to 1.5°C.
The IEA also found that large methane releases from the fossil fuel industry increased by 50% since the previous year, including probably the largest-ever release, from a 200-day oil well blowout in Kazakhstan.
Yet many actions to reduce methane emissions from the energy sector are cheap or even free. The IEA found that the UK energy sector was responsible for nearly a quarter of a million tonnes of methane emissions – equivalent to around 6 million tonnes of carbon dioxide in official accounts, or around 15% of Scotland’s current total emissions. Their analysis found that nearly 70% of those emissions could be avoided, more than 60% of the total at no cost at all to industry.
And of course the IEA analysis is based on only the official figures. Another new study, based on aerial surveys, concluded that there is three times as much methane leaking and being vented to the atmosphere from the US oil and gas industry as the government acknowledges. The authors estimate the social cost of these emissions at more than $9 billion.
A new satellite launched earlier this month will help get to the truth about methane leaks from the fossil fuel industry. MethaneSat will map methane emissions across wide areas at a level of detail not possible before, and the data will be public.
Low or no cost measures in agriculture and the oil and gas industry could rapidly reduce Scotland’s emissions, something we urgently need to do.
Dr Richard Dixon is an environmental campaigner and consultant
Image: Richard Hurd creative commons-attribution 3.0