Moves on methane will lessen climate impact

◆ Action by agriculture and oil and gas industries on CH4 could produce rapid results, writes Dr Richard Dixon

Some 25 per cent of Scotland’s contribution to climate change in 2021 came from methane. Because it is around 80 times more powerful at causing global warming than carbon dioxide in the short term, action to reduce methane emissions could bring about rapid reductions in our overall climate impact.

Emissions in Scotland mostly come from agriculture, the waste and energy sectors, and degraded land. Emissions from waste have fallen by nearly 80 per cent since 1990, mainly because we have captured the methane generated by rotting rubbish in landfill sites, using it to make energy or heat.

Emissions from the energy sector have fallen more than 80 per cent, mainly because of the disappearance of coal mining. Meanwhile, emissions from the agriculture sector have fallen by less than 15 per cent, mainly because of cuts in cattle and sheep numbers.

However, 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 per cent of the total. 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.

The energy sector’s emissions 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 (IEA) 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 still need to be cut by 75 per cent by 2030 if the global temperature increase is to be limited to 1.5C.

The IEA also found that large methane releases from the fossil fuel industry increased by 50 per cent in a year, including probably the largest-ever release from a 200-day oil-well blowout in Kazakhstan.

Yet many actions to reduce methane from the energy sector are cheap or even free. The IEA found that the UK energy sector was responsible for almost a quarter of a million tonnes of methane – equivalent to around six million tonnes of carbon dioxide, or about 15 per cent of Scotland’s current total emissions. Their analysis found that nearly 70 per cent of those emissions could be avoided, more than 60 per cent of the total, at no cost at all to industry.

And, of course, the IEA analysis is based solely on the official released 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 acknowledged. 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 the fossil fuel industry’s leaks. Methanesat will map emissions of the gas across wide areas at a level of detail not possible before, and the data will be in the public domain.

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.