the greenhouse gas that warms the planet faster than CO₂
In November 1776, while traveling on horseback between Italy and Switzerland, Carlo Giuseppe Campi saw bubbles in the marshes surrounding Lake Maggiore. He approached them and decided to investigate them. Almost by accident he discovered that they were flammable and He told it to his friend Alessandro Volta. Years later, Volta discovered that this gas was methane. Since then we have not stopped having problems with him. Colorless, odorless and highly flammable, methane (CH₄) It is a gas composed of one carbon atom and four hydrogen atoms. It is the simplest hydrocarbon and, in fact, is the fundamental component of natural gas (and therefore a key fuel for boilers, power plants and part of industry). In addition to the energy context, methane also appears in biological and geological processes: it is a chemical compound that arises, naturally, in the processes of anaerobic decomposition of organic matter. That is, in wetlands, in landfills, in the digestive system of ruminants or in large bags under the ground. Otherwise, methane is used for many other things. Not in vain, it is a raw material for the chemical industry and is an essential part of the production of hydrogen, ammonia or methanol. But the global conversation is not has been talking about methane for decades for none of that. Because, curiously, the big problem with methane is that it is a much more powerful greenhouse gas than carbon dioxide. After all, from what we know, its molecules capture between about 82 times hotter than CO2 (taking a period of 20 years as a reference). If we broaden the focus and use the 100-year term, its global warming potential is 29.88 times greater than that of CO₂. The only good thing, so as not to paint a picture that is too gloomy or malicious, is that it has an atmospheric half-life (11.8 years on average) compared to a much longer average. This explains why, despite collecting much more heat than the other, the long-term impact of methane is not so great. So? Well, it is an “accelerator” of short-term warming and, in that sense, it is a first-order problem for us. Not only because we are not moving forward; but because if we manage to reduce it, it can provide relatively rapid climate benefits. The problem is that it is not an easy thing to solve. On a planetary scale, annual methane emissions are around hundreds of millions of tons and 40% of them are due to natural sources that we cannot directly control. The other 60% is due, generally speaking, to human sources. According to the Global Methane Budget, there are three main causes: agriculture and rice, fossil fuels and waste. Agrolivestock Monika Kubala For years, experts have discussed the impact of livestock farming (especially ruminants such as cows and sheep). The calculation, in any case, is complex: not only is it difficult to estimate methane production from enteric fermentation (due to digestion), but things as ‘simple’ as manure management suffered from an “information blackout” that makes them very difficult to evaluate. In addition to this (and it is important), you must add the rice. Every year they consume more than 500 million metric tons of rice. That’s a lot of rice (it’s the main source of calories for 3 billion people), but it’s also a lot of methane: because, favored by floods that leave wide plains without oxygen, our gas rises to the surface. Fossil fuels Methane leaking throughout the oil, gas and coal chain is also difficult to measure, but less so. After all, leaks in wells and equipment, ventsinefficient flaring, outdated compressors, plumbing or storage are money wasted. And if we know how to measure something, it is money. The International Energy Agency esteem that the production and use of fossil fuels generated about 120 million tons of methane emissions in 2023. Waste, landfills and wastewater This case is the simplest and the one that most clearly shows that the methane problem really does not matter much to us: landfills, wastewater and other types of waste accumulation areas are areas especially conducive to the generation of methane (due to pure anaerobic activity) and since we do not capture it, it is released into the atmosphere. Thus, the atmospheric concentration of methane remains high and increasing. To give an example, NOAA estimated which, between 2023 and 2024, went from 1915.73 ppb to 1921.79 ppb on average. And, as I say, it is a shame because methane is surely one of the fastest routes: according to UNEP/CCAC, a strong reduction in human emissions (up to 45% this decade, with available measures) “could avoid almost 0.3 ºC of warming by 2045.” Biomethane (also called “renewable natural gas“) is the term that we have coined to refer to a methane of biological origin that is obtained, above all, by improving biogas: the CO₂ and other contaminants in it are eliminated until a gas rich in CH₄ is achieved and comparable, in almost all aspects, to natural gas. As a result of this process, a fuel is obtained that can be injected into the gas network. That is, it is an efficient way to take advantage of (and make the capture and processing economically interesting) a whole series of waste: from manure and sewage sludge to municipal waste or agro-industrial remains. Obviously, “green methane” does not automatically mean that it has “zero environmental impact.” Only that it has a biological origin and can be used like natural gas. For its environmental impact to be low, other things are required such as control of leaks, the origin of the waste or its impact on the network as a whole. Image | Katie Rodriguez In Xataka | The importance of the colors of hydrogen and what it means if it is green, brown, blue or turquoise
