Carbon dioxide (CO₂) is the main greenhouse gas and the one that focuses international commitments in the fight against global warming. But there is another villain who is usually in the shadow of CO₂, a powerful gas that is also trying to place in the foreground of the climate debate: methane. The latest IPCC report – the international panel of experts charged with laying the scientific foundations on climate change – blamed this gas for about 25% of the global temperature increase recorded on the planet since the pre-industrial era. And the United States and the European Union plan to launch at the next climate summit, which will be held in Glasgow in early November, an initiative for countries to commit to reducing methane emissions a 30% on 2030 regarding the levels of 2020. International organizations, scientific institutions and companies are now looking for formulas to tackle the problem, ranging from a red algae food supplement to reduce methane in cow burps to strengthening satellite monitoring of leaks linked to natural gas and oil.
Pep Canadell, one of the great international experts in monitoring greenhouse gas emissions and also one of the authors of the recent IPCC report, explains that science has been accumulating in recent years evidence on the effects of methane. In addition, in the last decade the emissions of this gas and its accumulation in the atmosphere “have grown faster than those of carbon dioxide”, explains Canadell from Canberra, where he works for the National Science Agency of Australia (CSIRO, its acronym). in English). This increase, he points out, is due to the increase in livestock and fossil fuel extractions, the main sources of emissions linked to human activity together with waste management.
From 1850, when the industrial age was consolidated, human activity led to an unprecedented increase in tens of thousands of years of greenhouse gas emissions. Part of these emissions are captured by nature through forests and oceans; and part of it accumulates in the atmosphere, preventing the planet’s heat from being released and triggering climate change. Carbon dioxide is the main gas and it is estimated that it can remain in the atmosphere for hundreds of years. Methane has a shorter life – about a decade – but its heating capacity is much greater. The IPCC estimates that one tonne of methane would be equivalent to 30 of CO₂ in terms of its potential to contribute to warming.
The agreement sponsored by the EU and the US for the reduction of methane seeks to be assumed by all the countries of the world. If this were the case, its promoters say that it would be possible to reduce warming by at least 0.2 degrees by mid-century, something that may contribute to achieving the increasingly difficult goal of keeping global temperature rise below 1 , 5 degrees with respect to pre-industrial levels – at the moment the planet is already at 1.1. According to information released Monday by the US State Department, there are already 31 countries that have announced their intention to join the so-called Global Methane Commitment. “Nine of the 20 are now participating in the commitment, which represents approximately 30% of global emissions and the 60% of the world economy ”, says the US Administration.
If broad support is achieved for this plan, it could be one of the most tangible results of the Glasgow climate summit, in which many hopes have been placed again, but from which it is difficult for many more commitments to emerge stronger than those that the great powers have so far put on the table. Among the countries that have already announced that they are joining the methane pact promoted by the United States and Europe, there is not China at the moment. Nor Russia and Iran, the two nations that expel the most emissions of this gas into the atmosphere linked to fossil fuels.
Oil, gas and coal
A recent study by the International Energy Agency (IEA) details that the 40 % of global methane emissions come from natural sources, mainly wetlands. The remaining 60% is linked to human activities: almost a 25% corresponds to agriculture and livestock, other 21% is due to fossil fuels and another almost 12% to waste.
The sector in which it is easier to act now is fossil fuels. More specifically, experts point to methane leaks that occur in the oil, gas and coal industry. As Canadell details, in these sectors large leaks correspond to a limited number of emission sources, which makes it possible to act to reduce the tons of this gas that end up in the atmosphere.
The same IEA report proposes a roadmap to reduce 75% of methane emissions from the fossil fuel sector from here to 2030. The experts of this agency propose measures such as imposing a tax on methane emissions of between 10 and 40 dollars per ton to force companies to tackle the problem or the implementation of border taxes levied on imports with the highest methane footprint.
One of the sections in which international analysts and the IEA put more emphasis is on leak control. “Today’s surveillance techniques often involve field inspection with optical gas imaging cameras, but new and emerging technologies, including continuous monitoring sensors, aircraft, drones and satellites, can significantly reduce the cost. to detect leaks, ”the report says. The first satellite detection of a methane leak was in 2016 and in just five years technologies have advanced a lot and almost every week events of this type are reported. Only in 2020, the European technology company Kayrros detected more than 500 leaks from the data offered by different satellites. “The next high-resolution and high-sensitivity satellites,” the IEA study points out, “will increase public awareness and aid regulatory oversight.”
The agreement promoted by the United States and the EU —To which a score of foundations have also joined that will support the initiative with 200 million dollars— further emphasizes the need to improve existing inventories to quantify emissions. And it implies an implicit support to the International Methane Emissions Observatory that is being prepared by the United Nations Environment Program (UNEP).
Methane and livestock
It is more complicated to act now on methane linked to agriculture and livestock as its sources are much more diffuse and numerous than in the energy sector. In this case, many glances are directed towards the burps of the cows.
Several companies, also linked to the Australian CSIRO where Canadell works, are experimenting with a type of red algae —the Asparagopsis taxiformis – which when administered as a dietary supplement manages to radically reduce the methane expelled by cows and other ruminants. “Cows continue to burp, but with very little methane in the gas mixture they expel,” explains Eva Faulkner, spokesperson for the Future Feed company, about the properties of the algae, who hopes to start marketing her supplement later this year o principles from which it comes.
This red algae acts on the microbes that generate methane in the ruminant’s digestion process. And the main challenge facing companies that want to exploit it commercially for livestock is its cultivation, says Faulkner. For now, some restaurant chains in the US have begun to experiment and advertise hamburgers “with low methane emissions.”
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