Methane emissions: Hiding in the shadow of carbon dioxide emissions

methane emissions, greenhouse gas
© Aleksey Zakirov

Here, we discuss how methane emissions are the second biggest contributor to human caused global warming after carbon dioxide (CO2)

While methane receives far less attention than CO2, reducing methane emissions will be critical for avoiding the worst effects of global warming.

The Green New Deal was the first high profile attempt to address methane emissions, but this was widely ridiculed as it effectively called for the global elimination of cows as a viable solution to reducing methane emissions.

Whilst it true cows and other livestock do produce methane, they also provide a valued contribution to the food chain with milk, cheese, beef, lamb etc. It is also impossible to accurately measure their methane emissions and estimates are used instead. No serious scientist, politician or environmentalist subscribes to the theory that wiping out entire species of livestock is a viable avenue for reducing methane emissions and other more practical solutions are being explored.

70 million tonnes emitted in 2020

It is estimated that oil and gas operations worldwide emitted over 70 million tonnes methane into the atmosphere in 2020. Converted into equivalent amounts of CO2, where one tonne of methane is equivalent to 30 tonnes of CO2; these methane emissions are comparable to the total energy related CO2 emissions of the European Union.

Oil production is responsible for around 40% of methane emissions today, with leaks across the natural gas supply chain accounting for the remaining 60%. Upstream oil and gas operations lead to more than three-quarters of total emissions. The 7.5 Mt drop in methane emissions in 2020 is equivalent to reducing annual greenhouse gas emissions by around 230 Mt of CO2.

Efforts to reduce methane emissions have been historically held back by a lack of reliable data, until The European Space Agency worked in collaboration with Kayrros, an earth observation organisation, to produce a methane tracker that incorporates data on large-scale methane leaks detected by satellite.

The debate on natural gas transportation so far

Until recently, the debate surrounding methane emissions during natural gas transportation has been focused on defective installations and devices resulting in small, ‘fugitive’ or unintended emissions. Thanks to powerful technologies, such as high-resolution satellite data, scientists are now able to underline the impact of frequent and intentional methane releases, also known as ‘venting.’

This interactive online tool by Kayrros has quickly become a global reference. It focuses on emissions from oil and gas operations, which is the area with the greatest and most cost-effective potential for reducing methane emissions.

It is estimate that around 10% of leaks in 2020 could be avoided at no net cost because the value of the captured methane is sufficient to cover the cost of the abatement measure. This share is smaller than in previous years because of unusually low gas prices in 2020, but it will expand again if natural gas prices rise, as they have done in early 2021.

Globally, around 5.5 Mt of methane emissions were detected by satellites in 2020. This is a drop from the 6.7 Mt of methane emissions that were detected by satellite in 2019. Reductions were seen across several regions in 2020, but large levels of methane emissions were still seen in US shale, in Turkmenistan and from pipelines in the Russian Federation.

The use of methane as a transport fuel is expected to increase, especially in heavy-duty road transport and in ships. Using methane instead of fossil fuels reduces particulate emissions. It could also reduce CO2 emissions by up to 20% if some technical problems are solved.

Methane is not properly burned

Methane is a particularly stable hydrocarbon and is not converted as efficiently as other hydrocarbons in combustion engines. At the high temperatures that occur during combustion, methane is burned just as completely as other hydrocarbons. However, in colder areas, such as near the combustion chamber walls and crevices, methane is not properly burned.

The oil and gas industry is facing capital constraints, and lower natural gas prices may make methane abatement and fuel development less of a priority. Regulatory action to reduce methane emissions is therefore more important now than ever before. Regulatory regimes in Canada and Mexico entered new phases of implementation in 2020, which also saw the release of the new EU Methane Strategy.

Drawing on the experience in these and other regions, a new Methane Regulatory Roadmap and Toolkit from the International Energy Agency provides a step-by-step guide for policy makers and regulators looking to develop new policies and regulations on methane.

Transparency on methane emissions is set to continue to improve, thanks to better reporting, including UNEP’s Oil and Gas Methane Partnership 2.0; more ground-based and aerial measurement campaigns; and readings from satellites.

While satellites provide an effective way to identify large leaks, they are not going to provide all the answers. However, reducing methane leaks into the atmosphere is the single most important and cost-effective way for the oil and gas industries to minimise overall emissions from core operations. Because oil and gas will continue to be part of the energy mix for decades to come, even in rapid clean energy transitions, it is crucial for the oil and gas industry to be proactive in limiting, in all ways possible, the environmental impact of their supply.

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