Editorial: The methane problem [Gas in Transition]

The global climate change discussion has chiefly revolved around CO₂ emissions and efforts to reduce them. But there is a growing view that methane mitigation too has a vital role to play.

This shift in focus was highlighted by a landmark report published by the UN on May 6 which concluded that cutting methane emissions was critical to avoiding global temperature growth. Reducing how much methane escapes into the atmosphere could also have a much more rapid impact than efforts to curb CO₂ emission, the UN Environment Programme (UNEP) argues in its Global Methane Assessment.

“Cutting methane is the strongest lever we have to slow climate change over the next 25 years and complements necessary efforts to reduce CO₂,” Inger Andersen, UNEP’s executive director, explains. “The benefit to society, economies and the environment are numerous and far outweigh the cost.”

CO₂ has been the main driver of climate change, although methane comes in second place owing to its much greater potency, UNEP argues, even though it is released in much smaller volumes. UNEP finds that methane has been responsible for around 30% of global warming since the pre-industrial era. And its atmospheric concentration is currently increasing faster than at any time since record-keeping began in the 1980s. Failure to act could see methane emissions continue rising through at least 2040, the organisation warns.

Avoiding further temperature growth is one clear reason to act, according to the report. But there are other gains to be made by addressing methane. For one, it is a key ingredient in smog, with UNEP estimating that its mitigation could prevent some 260,000 premature deaths and 775,000 asthma-related hospital visits annually, as well as 25mn mt of crop losses.

The good news is that methane decomposes in the atmosphere much faster than CO₂. Whereas CO₂ can take hundreds of years to break down, methane has an atmospheric lifetime of roughly a decade, according to UNEP. This means that efforts to rein in methane emissions will take far less time to yield results, it says.

Through a concerted effort, UNEP argues, methane emissions from human activity could be cut by 45% as early as 2030. This reduction of around 180mn mt/year could avoid almost 0.3 ^oC of temperature growth as early as the 2040s, it says.

The onus falls largely on the oil and gas industry to tackle the methane problem, according to UNEP. The sector is not the biggest contributor of human-caused methane emissions – an honour that falls on agriculture – but it is the area where the greatest reductions can be achieved.

The oil and gas sector accounts for only 23% of total human-caused methane emissions, whereas agriculture, chiefly livestock, causes around 40%. Waste contributes a further 20% and coal mining 12%. However, UNEP’s assessment identifies available solutions that could reduce methane emissions from human activity by 30%, and these are mainly found in the hydrocarbon sector.

“The fossil fuel sector has the greatest potential for targeted mitigation by 2030,” the report states. “Readily available targeted measures could reduce emissions from the oil and gas sector by 29-57mn mt/yr and from the coal sector by 12-25mn mt/yr.”

What is more, most of the 30% reduction in human-caused emissions could be achieved at a low cost, and just over 50% at negative cost, meaning that the measures would pay for themselves quickly. In the oil and gas sector, up to 80% could be implemented at a low or negative cost. This negative cost is largely derived from using the methane that would have escaped into the atmosphere as energy. It lists specific measures such as improved upstream and downstream leak detection and repair, better control of unintended fugitive emissions from production and more advanced monitoring.

It also suggests that a rising global tax on methane emissions starting at around $800/mt, which could reduce emissions by as much as 75% by 2050.

Measures targeted at methane reduction alone are not enough, however, the report states. To achieve the full 45% cut envisaged by 2030 across the hydrocarbon, agricultural and waste sectors, additional measures must be implemented that do not target methane specifically, such as shifting to renewable energy, improved residential and commercial energy efficiency and a reduction in food loss and waste.

The report also flags key challenges to overcome, namely incomplete knowledge and monitoring of emissions in some sectors, limiting potential for technical innovations in mitigation and strategic decisions on efficiently reducing emissions. There also needs to be greater regional and global coordination and governance of emissions, beyond local and national laws and voluntary programmes already in place, it argues.

While most government climate targets concern CO₂ emissions, legislators are starting to set their sights on methane. The European Commission is currently drafting legislation to strengthen methane reporting and monitoring requirements for oil and gas companies, after publishing an EU methane strategy last year. In the US, the Biden administration is now reinstating methane emission regulation that had been dismantled by its predecessor.

The UNEP report is likely to push the climate change conversation further in the direction of methane. And its publication comes ahead of the UN Climate Change Conference (COP26), where world leaders will try to outdo themselves in making old climate pledges new, including on methane. However, measuring methane emissions is a contentious issue. There is much disagreement about how much methane each sector contributes, and over which measurement methods should be used. Creating the right legislation to help rather than hinder various industries from addressing their environmental impact will be no small task.