Methane gas emissions: a key greenhouse gas crucial to mitigation efforts

How potent is methane as a greenhouse gas compared to carbon dioxide?

Methane is the main component of natural gas and it is extremely effective at trapping heat, much more than carbon dioxide (CO₂). People generally link global warming with CO₂ but, as the recent EEA briefing explains, half of the increase in global temperature since pre-industrial levels is due to higher methane or CH₄ concentrations in the atmosphere. This is based on science from the Intergovernmental Panel on Climate Change (IPCC).

Given this, we need to start focusing our attention on this potent greenhouse gas as a key climate mitigation priority, while still ensuring we reduce emission of other gases like carbon dioxide.

So should we prioritise reducing methane emissions as part of European efforts to reduce GHG emissions? 

Absolutely! And there are at least three reasons to do so. The first, as I mentioned earlier, is that methane concentrations are responsible for about half of the increase in global temperature and the associated climate impacts.

The second reason is that due to the rapidly increasing methane concentrations, the global warming effect of methane has increased markedly in the past years relative to CO₂.

And the third reason is that when countries report greenhouse gases or do climate mitigation analysis, they use the agreed global warming potentials over a period of 100 years. However, methane lives in the atmosphere for around 12 years, and in shorter periods of time, it actual global warming potential is much higher. For example, according to the IPCC Fifth Assessment Report (AR5), methane is 84 stronger than CO₂ over 20 years, compared to 28 when considering 100 years. This basically means that current methane emissions are three times worse for climate change in the short term. Also reducing them more rapidly would be three times more effective.

For all these reasons, our recent EEA briefing concludes that one of the most immediate and effective mitigation strategies, or low hanging fruit, to limit global warming in the short term is to tackle methane sources and reduce its emissions fast.

Of course, focusing on methane does not mean we lose focus of the other gases. Reductions in all greenhouse gases are needed to achieve the long-term climate goals.

What new technologies can be used to reduce methane emissions?

There are several technologies available. You have, for example, landfill gas recovery from waste or biogas produced from agricultural manure. These can be used directly for energy or/and upgraded to biomethane to produce heat and electricity. Biogas in particular has a big potential to reduce methane emissions in the agriculture sector.

Also, one can also use the recovered methane in the production of hydrogen, although we should favor green hydrogen produced from renewable energy sources, such as wind and solar power, because it results in zero emissions.

Reducing methane emissions improves both climate change mitigation and better air quality, because of the synergies in the reduction of greenhouse gases and air pollutants. Also, the methane that is recovered can partly replace the use of imported natural gas, and hence improve energy security to some degree. We need to think ‘circular’ because it reduces greenhouse gas emissions, improves air quality and reduces our energy dependency.

What are the top sources of methane in general and what are the problematic methane emission sources in Europe?

Maybe first to clarify that methane emissions originate from both natural sources and human activity. The natural methane comes from wetlands, termites, oceans, hydrates (CH₄ trapped in water at low temperature and under high pressure), forests, wildfires, wild animals, permafrost and geological sources.

The International Energy Agency (IEA) has estimated that about 40% of global methane emissions are from natural sources, and the remaining 60% come from human activities. Of the latter, the energy, agriculture, and waste sectors are the largest sources of methane emissions.

The key methane sources worldwide are also those found in Europe, although their importance varies. Methane is usually a larger source of greenhouse gas emissions in countries with bigger agriculture sectors (livestock mainly) and/or with a lack of adequate waste management systems or having poorer pipeline infrastructure for natural gas.

In the EU, 12% of total greenhouse gas emissions in 2020 were of methane, and of this, half of the emissions came from the agriculture sector. The trends have been positive in the past 30 years since 1990, with methane emissions down substantially in energy supply, waste management and, until recently, in agriculture. Reduced emissions reflect a decrease in agricultural livestock, lower levels of coal mining; improved oil and gas pipeline networks; less waste disposal on land, and an increase in recycling, composting, landfill gas recovery, and waste incineration for heat and electricity.

Though past performance has been positive, further reductions of methane emissions become increasingly difficult, though not impossible, in the agriculture sector. In addition to the advancements and implementation of methane-reducing practices and technologies, the food choices made by consumers can also contribute to lower methane emissions.

What further actions is the EU taking to reduce methane emissions?

The EU is taking many actions to reduce emissions, including methane emissions. In fact, the list of policies that do that is quite long, as explained in the briefing. The policies implemented by the EU go in the right direction, however, we are unlikely to fully mitigate methane emissions because we need an agriculture sector — unless of course we manage to capture all methane.

Even if we were to fully mitigate emissions, the EU’s efforts may not move the needle to mitigate climate change globally. International cooperation and international agreements are essential to ensure that we don’t exceed the 1.5 C global rise in temperature, as the EU only accounts for 7% of global emissions and for less than 5% of methane emissions.

There are several international activities linked to global efforts to mitigate greenhouse gas emissions, including methane, but these take time and developing country Parties (as signatories to international agreements and conventions) also require financial assistance in the trillions to cut their emissions and meet their international climate commitments.

What work is the EEA doing in this area? 

Our recent briefing is a first in the sense that it puts things together for policy makers and the general public. I hope it will reach those who can have an impact reducing emissions from this powerful greenhouse gas. Implementing and developing technologies and policies to reduce methane emissions will be the best climate mitigation strategy to slow down global warming in the short term.

The EEA has also developed a ‘methane emissions’ data viewer to underpin the briefing, where users can see countries’ methane emissions as reported in their greenhouse gas inventories. The viewer shows that, even within Europe, there are significant differences in methane emissions across countries.

Ricardo Fernandez

EEA climate change mitigation expert and coordinator of the EU’s GHG inventory to the UNFCCC