Methane Bombs
Methane leaks are an increasingly concerning environmental problem, particularly due to their significant impact on climate change. New satellites have made it possible to detect and catalog methane leaks around the world. Stopping these methane emissions is an important lever for mitigating the effects of climate change.
What is Methane and why is it important?
Methane, CH4, is the second most important contributor to greenhouse gases that contribute to climate change, after carbon dioxide. The main human activities responsible for methane emissions are:
Livestock farming : enteric fermentation that occurs in the stomachs of cattle emits methane. To put it simply, cow burps (and not farts) emit methane.
Rice cultivation : methane is produced by the lack of oxygenation in soils that are constantly waterlogged.
Waste : the decomposition of organic waste in landfills produces methane.
Fossil fuels : at oil and gas extraction sites and in coal mines.
Unlike carbon dioxide, methane is significantly less abundant in the atmosphere. In 2020, methane accounted for less than 20% of global greenhouse gas emissions while CO2 made up nearly 75%. So why is it so important to focus on methane emissions?
Because although less present than CO2, its capacity to trap heat is much greater: its global warming potential is estimated to be 28 times higher than that of CO2 over a 100-year period! This means that emitting 1 tonne of methane into the atmosphere will have, over the course of a century, the same impact on temperature increase as emitting 28 tonnes of CO2.
This figure triples when considering the impact that emitting one tonne of methane will have over the first 20 years following its emission. And for good reason: unlike CO2, which has an average lifespan of several centuries, a methane molecule has an average lifespan of 12 years. This means that it is during the first years following the emission of a methane molecule that it contributes most to climate warming. But it also means that a rapid decrease in methane emissions can mitigate the effects of climate change within a few years.
Super methane emitters
In order to reduce methane emissions, it is necessary to know who is emitting methane, how, and how much. By analyzing the distribution of methane emissions at the global scale, it becomes clear that a small but influential fraction of projects, nicknamed "super-emitters", is responsible for a large portion of these emissions. These significant emissions come mainly from oil and gas operations, urban landfills, and coal mines. However, they are not always well documented in national emissions inventories because they often result from occasional malfunctions, such as faulty gas flares.
For this reason, a team of researchers has developed tools to automatically detect these super-methane emissions from satellite imagery. In 2021, these researchers catalogued nearly 3,000 projects scattered across the world, primarily concentrated in Asia and North America.
Mapping of super-emitter methane sources in 2021 by emission source
A recent study highlights a promising perspective on reducing methane emissions: the adoption of already existing technologies could significantly reduce them. These technologies, which are not only effective but also economically viable, thus represent a major opportunity for environmental policies and companies in the sector.
What about Morocco?
Conclusion
Article by Mehdi Mikou