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There’s Something About Methane

By Joel Martin, SanDiego350 Climate Writer

The behind of a cow, fracking well, and food waste with the words "methane".

Methane levels in the atmosphere are climbing dramatically. This is scary news since methane is a far more potent greenhouse gas than carbon dioxide. According to NASA, methane has already been responsible for 20 to 30% of global warming since the industrial revolution. The rate of accumulation of methane jumped by a factor of 3 between 2010 and 2020 and it looks to be increasing still faster. 

Where is all this methane coming from and why is it increasing so quickly? We’ll answer that question and explore some of the ways SanDiego350 is working to reduce different sources of methane.

First, it’s worthwhile reviewing two key differences between carbon dioxide and methane because those differences have a profound impact on climate policy. First, methane absorbs far more heat energy (infrared light) than carbon dioxide, making it an extremely potent greenhouse blanket. Methane traps roughly 28 times more heat per weight than carbon dioxide*. Second, it disappears with a half-life of about a dozen years as sunlight causes it to react with oxygen to form carbon dioxide (in contrast to carbon dioxide itself which persists for many hundreds years.) Since methane is both potent and goes away quickly, targeting methane emissions could have a profound and nearly immediate impact on countering global warming.

Worldwide, an estimated 60% of methane comes from human-associated (anthropogenic) sources such as agriculture, fossil fuels and landfill waste. According to the EPA , China, the United States, Russia, Indonesia and Mexico are the world’s biggest culprits. Natural sources, in particular wetlands, account for the remaining 40%.

In the United States, the largest human-associated methane source is the fossil fuel industry, totaling 35% of all emissions. (That is according to self reporting, but satellite measurements indicate that companies are underreporting their leaks by more than a factor of two.)  The bulk of this emission comes from wasteful leaks in the industry’s drilling and distribution of oil and gas. If we burned all of the methane, it would produce carbon dioxide. That wouldn’t be great but leaking methane directly into the atmosphere makes the problem 28 times worse.

Domestic livestock are the second largest methane source in the U.S., contributing a whopping 33% of methane emissions. That breaks down into 25% enteric fermentation (cow burps) and 8% manure management. Every cow belches about 220 pounds of methane per year.

Though awareness is growing about the environmental impacts of meat and dairy production, the industry is working hard to misinform and confuse the issue. Instead of simply reporting methane, they want to use a screwy metric called GWP* (pronounced “G-W-P star”), a metric guaranteed to confuse everyone. The industry’s GWP* argument goes as follows: since methane goes away with a half-life of a dozen years, we should only measure changes in methane production, not current methane production. This gives the industry an absolute get-out-of-jail-free card. Even the world’s largest agricultural methane producer would get a score of “zero” if it didn’t increase its methane production and only a small GWP* if it did grow. This clever ruse, which has been called “incomprehensible science” by the U.K.-based Changing Markets Foundation, will likely be used by meat and dairy industry lobbyists to confound lawmakers worldwide. 

Energy and agricultural sources of methane are increasing, not decreasing. The United States is the largest producer and exporter of natural gas and our production jumped by a colossal 20% from 2020 to 2021. Furthermore, U.S. exports are expected to double between now and 2027, an increase that Bill McKibben calls, “The Single Most Dangerous Expansion of Fossil Fuel in the World”. Things are going in the wrong direction and it’s hard to imagine how other countries can see us as anything other than the world’s biggest climate criminal.

Natural methane emissions are growing too, largely due to the rising global temperatures we’ve already caused. These emissions are the product of microbes feeding on organic matter in swamps, bogs, marshes and wetlands. As the climate warms these processes accelerate, resulting in even faster methane release. NASA funded research also demonstrates that the expected thawing of the permafrost may result in a much larger release of methane than is assumed in current climate models. Though we can’t do much to stop these emissions, we do need to take them into account because natural methane emissions are a knock-on effect that amplifies human caused climate change. In other words, increases in natural methane release aren’t really ‘natural’ in the normal sense of the word. We are the ones causing it.

All of these factors point to the importance of and our compatriots in the fight against climate change. What we do to reduce the emission of methane will have a profound impact in our own lifetimes – and we can do a lot. 

For example, the California State Senate and State assembly recently approved two bills that SanDiego350’s Legislative Team advocated for during the 2023 legislative session that will require companies doing business in California to disclose greenhouse gas emissions. That will bring much needed transparency to where the pollution is coming from, draw attention to the biggest culprits, and increase public pressure to do more. We will continue to apply pressure to get further legislation requiring the repair of methane leaks and penalties for those who don’t comply.

The best solution is to stop drilling but, in the interim, big methane leaks are a horrible problem. Leaks can be easily fixed. It’s not rocket science, it just takes money. For example, when a pipeline needs a repair, most companies simply vent the natural gas directly to the atmosphere rather than capturing it. That’s a legal practice that we have to make illegal. In other situations, companies are supposed to flare (namely, burn off) methane when they are drilling for oil but oftentimes these flares are unlit or broken and the gas escapes into the atmosphere. Inspections and substantial penalties for broken or unlit flares would reduce emissions. There are innumerable points along the production and distribution system where technological solutions exist for decreasing emissions. We just need to put in place legislation that tips the economics and forces gas companies to be good corporate citizens. 

In addition, California should be leading the way on reducing extracting and distributing oil and gas in favor of electrification and renewable energy (which would reduce or eliminate methane from our homes and atmosphere). To that end, SanDiego350 works to expose our investor-owned utility, SDG&E, and its parent company Sempra (an international fossil fuel company working to expand methane gas extraction and distribution) – read more at our campaign website, Sempra Fracks Our Future (especially see the “dirty secrets” page).

As to the agricultural production of methane, an obvious solution is to eat less meat and dairy, something that is environmentally sound, healthy and easy on our pocketbook and our conscience. Changing peoples’ minds in this regard will take time and persistence. The cowboy mythos combined with extensive advertising (“Beef. It’s What’s for Dinner”) have ingrained beef consumption as something that’s almost a patriotic duty for many here in the United States. You can make your own contribution and start to shift peoples’ thinking by simply cutting back. SanDiego350’s Food and Soil team has been working on getting more plant based food options in schools as well as educating classrooms about the benefits of plant-based eating on our environment. 

Here in San Diego, the biggest local source of methane is rotting food in the Miramar and Otay Mesa landfills. You can reduce that problem by making sure that you put your food waste in your green compost bin every week. SanDiego350’s Food & Soil Team has been educating the public about the recently distributed Green Bins, to make sure residents understand the issues and use their bins to maximize these benefits. Beyond that, we can push for landfills to capture and use the methane to produce electricity. The U.S. Navy completed a methane capture and microgrid system at the Miramar landfill in March 2021. That system has saved the Navy over $90 million. An audit of the State’s landfills could find more landfills amenable to this solution.

Cattle farms can reduce methane emissions by using food additives, as they can reduce emissions by one third. Farms can also use anaerobic digestion tanks (essentially fancy composting systems) to reduce methane emissions by 50%. Smaller farms can also employ simpler, lower-cost manure management practices to reduce methane emissions. A legislative carrot and stick approach could promote best practices and discourage poor manure management.

There are three key takeaways. The first is that, unlike carbon dioxide, we fortunately already have many technical solutions in hand for dramatically reducing methane release. The second is that, because methane gets destroyed in the atmosphere, our actions can produce real results in a short period of time. The final and most important takeaway is that the fossil fuel industry is going to continue to do everything in its power to keep producing more of every type of fossil fuel, because it is most profitable to do just that. We need to change the economics so that it is more profitable to capture methane than to dump it into the atmosphere as a first step toward eliminating fossil fuels entirely.

* Greenhouse gas emissions are generally listed by weight. Sometimes the relative greenhouse effect of methane is cited as the much larger number of 80x. This refers to the effect by volume or moles of gas emitted.