How to reduce methane emissions? Put food waste in the compost bin (not garbage), change the way we raise and eat cows
President Biden was at the United Nations climate summit (COP26) in Glasgow today, announcing that more than 90 countries would try to cut methane emissions by at least 30% by the end of the decade.
“They have many big polluters, like Brazil, which is signing a commitment on methane for the first time. Nigeria, European Union, Indonesia and even Iraq. But so far, Russia and China – two major emitters – as well as India are absent, ”explains Paasha Mahdavi, professor at UC Santa Barbara who studies energy and environmental policy.
He adds: “It’s a fruit at hand in the battle of emissions. … This is a very clear way to reduce future warming, just by looking at methane, by 0.2 degrees Celsius by 2040. So that’s a big chunk. And that commitment is going to get us a third of the way, assuming no one else signs. “
Methane vs CO2
Compared to carbon dioxide, how powerful is methane i.e. how much heat can it trap and how much does it affect surface temperature? Estimates vary because methane dissipates through the atmosphere faster than carbon dioxide, and that depends on the time period you’re looking at, Mahdavi explains.
“So the methane emitted now, and you go for the next 20 years, methane is just over 80 times more potent than carbon dioxide. And over a 100 year period… it wears off faster, so it’s 30 times more potent. And then beyond that, it dissipates even faster. Carbon dioxide is therefore a longer term problem, it stays in the atmosphere much longer. But in the short term, the methane is just brutal.
New regulations on industrial activities
President Biden wants the US Environmental Protection Agency to impose fines on oil and gas companies that do not cap their emissions, and provide them with incentives to meet those caps.
“A lot of what’s planned involves regulatory changes that don’t require congressional approval, so that’s key. So this is… better monitoring and enforcement by agencies – like the EPA, Bureau of Land Management, Bureau of Ocean Energy Management – to reduce methane emissions from industrial activities. So not just oil and gas, but other industrial activities that take place on public lands and in federal offshore waters. And that in itself is a huge slice of the pie, ”says Mahdavi.
Where does human-made methane come from?
About 35% of this comes from oil and gas production, 57% from agriculture (mainly livestock) and landfills, and 8% from biomass and biofuel combustion (forest fires) . That’s all according to the Global Carbon Project, says Mahdavi.
Added to this complexity is the “carbon cycle feedback problem”. He explains, “As the planet warms due to climate change, it melts more permafrost. This is a big problem because permafrost stores a lot of methane. This therefore releases even more methane into the atmosphere as a direct result of global warming. So it’s quite a mix.
Why does food waste in landfills produce so much methane?
Ferris Kawar, sustainability manager at Santa Monica College, explains that when things enter a landfill, they are crushed by machines, then covered in dirt and crushed again. All the air is forced out, creating methane, which is also why landfills smell so bad.
So consumers should be more careful about how much food they throw away.
“They’ve got it in the fridge for a few weeks, they’re looking at the freshness date, and they’re like, ‘Oh, I’ve got to get rid of it.’ But it really doesn’t need to be thrown away. We can shop better. We can use the sniff test beyond just the fresh date.… The manufacturers want you to throw it away faster than it should be. ‘be,’ says Kawar.
Compose and use green bins (compost)
Turning food scraps into compost involves breaking down the waste using air, water, microorganisms and heat.
“If you go to a composting facility, it actually smells a lot different because it’s a whole different process. This creates a bit of carbon release in the composting process. But it’s much less powerful… than the release of methane, ”explains Kawar.
He notes that Los Angeles has a new program called RecycLA, which requires carriers to provide bins that can be used for both compost and green waste (like yard leaves). “Now it can also accept food scraps, bones, meat, dairy… anything that comes out of your kitchen. “
Livestock husbandry and consumption
Kawar says cows make up 58% of California emissions, so people can make a big difference just by eating less meat.
An innovative idea is to add red algae to the diet of cows, he points out. “They have several chambers in their stomachs. And it’s not designed to be fed soy and corn, which typical feedlot cows get. And so when they digest that kind of material, it creates additional methane. And if you add algae to this type of food, it will help reduce it by 70-80%, studies show.
This story is part of Cover the climate now, a global journalistic collaboration boosting coverage of climate history at the United Nations Climate Change Conference (COP26) in Glasgow.