According to the EPA , roughly 50 to 65 percent of U. About 27 percent of methane emissions are generated through a process called enteric fermentation—cows burping and occasionally farting while they digest their food, basically—and 16 percent of global methane emissions are generated by organic waste decomposing in landfills.
Methane can be also be released through the storage and use of manure for fuel 9 percent and through coal mining 8 percent.
As for the belching bovines, a recent study published in Science Advances identified groups of microbes in cows' guts that cause enteric fermentation and suggested that selectively breeding cows to produce less gas might lower emissions. Studies have shown that, over a year period, a kilogram of methane warms the planet as much as 80 times more than a kilogram of carbon dioxide. Methane lasts for maybe a decade in Earth's atmosphere before it begins to react with a free radical called hydroxyl and turns into carbon dioxide, where it can stay there for centuries.
Therefore, most of methane's time in the atmosphere as a molecule is spent as a CO2 molecule, Varon says. Far less methane is emitted into the air than carbon dioxide.
Still, methane leaves lasting impacts. For example, one of these impacts is a phenomenon called thermal expansion. Greenhouse gases like methane heat up the atmosphere, and as much as 90 percent of that excess heat is absorbed by the oceans.
This heat causes seawater to expand in volume. This effect, along with glacial melting, causes sea levels to rise. In , scientists ran computer simulations that showed thermal expansion caused by methane continues for centuries even after the gas has dissipated from the atmosphere.
And finally, there are health benefits to regulating methane. Emitting the gas can actually lead to higher levels of ozone in the atmosphere, says Varon. Ozone can cause a number of health problems such as shortness of breath and aggravate lung conditions like asthma, emphysema, and chronic bronchitis, according to the EPA. He and his colleagues work with government agencies that use satellites to pinpoint where emissions are highest.
This information can help identify facilities that are leaking methane and lead to better monitoring, and subsequently, regulations of oil and natural gas operations around the world. Top COP26 stories: China and the US reach emissions deal; aviation sector seeks sustainable jet fuels; call for global agreement on sustainability reporting standards. I accept. Take action on UpLink. Forum in focus. Read more about this project. Explore context.
Explore the latest strategic trends, research and analysis. License and Republishing. Written by. More on Future of the Environment View all. Simon Torkington 12 Nov COP Everything to know about the climate change summit on 11 November Top COP26 stories: China and the US reach emissions deal; aviation sector seeks sustainable jet fuels; call for global agreement on sustainability reporting standards.
Simon Torkington 11 Nov Equality, justice, and investment in nature must be at the heart of the corporate climate response Hina West 11 Nov Methane is more than 25 times as potent as carbon dioxide at trapping heat in the atmosphere. Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities. Because methane is both a powerful greenhouse gas and short-lived compared to carbon dioxide, achieving significant reductions would have a rapid and significant effect on atmospheric warming potential.
China, the United States, Russia, India, Brazil, Indonesia, Nigeria, and Mexico are estimated to be responsible for nearly half of all anthropogenic methane emissions. The major methane emission sources for these countries vary greatly. For example, a key source of methane emissions in China is coal production, whereas Russia emits most of its methane from natural gas and oil systems. The largest sources of methane emissions from human activities in the United States are oil and gas systems, livestock enteric fermentation, and landfills.
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