When looking at greenhouse gases and methane emissions, many are asking, how does methane affect global warming and how can we reduce greenhouse gas?
How Does Methane Affect Global Warming
With accelerating levels of greenhouse gases, many are asking the question, how does methane affect global warming? The Earth is blanketed by a layer of gases, which we call the atmosphere. The blankets’ composition directly corresponds to what waves can go in and out. The composition of the atmosphere changes based on natural Earth processes and human activity. Due to the chemical structure of methane, it is many times stronger than carbon dioxide in its ability to trap heat. This is why methane greenhouse gas is under scrutiny.
“Today, half the methane in the atmosphere comes from people,” says Dr. Sheel Bansal, a Research Ecologist at the USGS Northern Prairie Wildlife Research Center in Jamestown, North Dakota. The three main contributors of human-caused (anthropogenic) sources of methane include cows and the associated agriculture, fossil fuel extraction, and landfills.
Natural fluxes of methane greenhouse gas include wetlands, inland waters, geological, oceans, termites, wild animals, permafrost, vegetation, and chemical reactions in the atmosphere.
Methane Greenhouse Gas
Greenhouse gases work like the panes of a greenhouse. The plate of glass allows visible light in the building. Visible light has a short wavelength. The molecules of the glass are transparent to visible light, allowing it to enter. Once these waves heat up, they become longer and change into infrared. These longer wavelengths of electromagnetic radiation, which we call heat, can’t pass through the plate of glass or, in our atmospheric case, the gases.
“What you don’t want is a big blanket surrounding the Earth that’s preventing those infrared radiation wavelengths from escaping,” Dr. T.H. Culhane says. “Otherwise, the earth can’t regulate.”
Culhane is an Associate Professor at the Patel College of Global Sustainability at the University of South Florida. He is the Director of the Climate Mitigation and Adaptation concentration.
The buildup of heat isn’t just from the sun coming through the atmosphere and then striking the surface. It is also from the earth’s interior, like volcanoes and magma.
“This planet has always self-regulated by having this open window in the greenhouse, particularly at night. And we’ve started blanketing it,” Culhane explains.
Our greenhouse gases (the big hitters include water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) are opaque to infrared waves. They prevent infrared waves from going through. The more we contribute to the composition of the atmospheric blanket, the more heat we will retain.
“It’s worth knowing that the earth was blanketed by methane in the early years,” Culhane says. “But biological, chemical, and physical processes changed that.”
Culhane says that the first organisms on the earth were making methane, hence that big methane atmosphere we once had. But when oxygen-creating organisms, like cyanobacteria, evolved, the oxygen levels rose in our atmosphere, poisoned almost everything else, and a big extinction event took place.
This change drove the methanogens (organisms that produce methane) like the archaea into the deep recesses of the earth, under the ocean, under the lakes and streams, and into the bodies and cells of evolving multicellular organisms.
Meanwhile, the methanotrophic organisms (ones that eat methane) converted the methane back into carbon dioxide and water, which went to the plants. The plants then turned it back into more vegetation and more life. There was a balance. And yes, there were also some hiccups along the way prior to humans.
Cyanobacteria were putting too much oxygen in the atmosphere for what existed at that time. Today, humans are putting too much carbon dioxide, methane, and nitrous oxides into the atmosphere for what exists here today.
“And that’s a bad thing for those of us who are charismatic megafauna, like human beings, elephants, and panda bears,” Culhane says.
“Termites release an awful lot of methane,” Culhane explains, “but when we opened fossil reserves where both living methanogens and long-dead methanogens had been creating methane in massive pockets under the earth – that is when we overwhelmed the system.”
There is an enormous pool of hydrocarbons in the earth, which we’ve been burning as oil and releasing as carbon dioxide. That’s our main culprit in greenhouse gas. But coal, another plant product made from old forests, has been releasing all the methane emissions (another greenhouse gas) associated with those once-buried pockets now, too.
Due to fracking and drilling, we are releasing all this methane that’s under the surface. The methanotrophic organisms simply cannot keep pace because they mostly live under the surface.
Methane Greenhouse Gas from Cows
In addition to fracking and drilling, cows also produce a lot of methane and are often vilified in climate change conversations.
“In pre-industrial circumstances, cows were eating, walking, pooping, farting and burping – the main release of methane from them,” Culhane says. However, he adds they weren’t belching up as much methane because they were grazing, moving, and eating a diet that was gentler to their stomach. Today, many of them are raised in Concentrated Animal Feeding Operations (CAFOs). With these concentrated numbers, methanotrophic organisms cannot keep up. In addition to the large number of animals in a small area, it is also due to their new diet.
“You’re getting them in these feedlots where now you’re using fossil fuels,” Culhane says. “We’re using hydrocarbons to artificially grow sugary and starchy grain like corn, wheat, or soy. And you’re taking that and using fossil fuels again to transport and concentrate it. They didn’t evolve to eat these grains.”
Culhane compares them to people who eat too much and then become bloated. The methanogens living inside them are working overtime, trying to break down all these starchy, sugary foods that are not good for the animals. And as a result, they are burping out enormous amounts of methane.
A 2020 Burger King commercial said they will add lemongrass to their cows’ diet to reduce their methane emissions. According to their research, it should reduce their cattle methane production by 33%.
According to the College of Agricultural and Environmental Sciences at the University of California, Davis, feeding cows seaweed can reduce their greenhouse gas emissions by 82%.
The overall total number of cows is not that significant when you consider the numbers of bison that were here before Europeans. Culhane, who has helped the Maskoke ecovillage in Alabama on biodigesters, said they are working on bringing back forest bison.
“There were 4 million, they estimate, in Alabama, Georgia, Florida, and other southern states. We think of them as a plain’s animal, but whether they were on the plains or were here, they were always browsing and grazing mosaic landscapes of enormous complexity where certainly the methanotrophic and other organisms were officially there to recycle these molecules.”
And while there were millions and millions of bison in large herds, we can’t call it crowding because it was filled with all sorts of other organisms. It was part of the tapestry of life.
Culhane adds, “If you took bison and shoved them in a CAFO, we would probably be in a similar problem – particularly if you distorted their diet and fed them grains that were not conducive to proper digestion.”
Methane Emissions from Wetlands
The problem of reduction in ecosystem complexity and then having methane releases that are greater than what that ecosystem can accommodate is what’s making methane a problem. We can’t eliminate methanogens or methanotrophs, and we shouldn’t try to.
“To say that methane is a villain or that carbon dioxide is a villain is to misunderstand geochemistry and biology. Plants can’t live without carbon dioxide, and we need plants,” Culhane says. “We need to understand this is a rate problem.”
Termites, wetlands, lakes, and ponds are all releasing methane constantly. It’s just a feature of life, Culhane says.
According to Dr. Bansal’s new USGS study, if the climate gets warmer, it is likely to cause freshwater wetlands to release 2 to 3 times more methane emissions compared to normal conditions.
“If we calculate how much to reduce our methane emissions without considering how warming is affecting the processes creating natural emissions, we risk missing the mark when we account for our mitigation efforts,” Bansal explained. He adds, “Since industrialization, people have added another 1.5 blankets of methane greenhouse gas to the existing atmospheric blanket, and we keep adding more.”
If people reduce their methane emissions, then the blankets start peeling off. However, if the climate warms too much, wetlands will start adding back to the blanket layers.
In aquatic places like wetlands, microbes feed on organic material and produce methane as a waste product. How much methane they produce depends on many factors, including hydrology, temperature, vegetation, and wetland size.
Bansal’s study showed the conditions in wetlands that lead to methane production are also good at removing and storing carbon dioxide from the atmosphere. Wetlands are known areas of carbon sequestration, also known as carbon sinks. Carbon dioxide is taken from the air through photosynthesis. When the plants die, they decompose on site and form organic soils. The building of soils takes a long time; therefore, the older a wetland, the more carbon it stores. Scientists estimate that despite wetlands only covering 3-5% of the earth’s surface, up to half of all the organic carbon is stored in terrestrial soils found in wetlands!
We can’t vilify wetlands for their methane emissions because it is in balance with the atmosphere. Wetlands produce methane at the same rate it is breaking down; however, their removal of carbon dioxide is continuous.
How to reduce methane emissions
In addition to feeding cows a proper diet and reducing our dependency on fossil fuels (which are huge), focusing on “waste” management can also be helpful in reducing methane emissions. Waste is only waste when it is at the wrong location or in the wrong concentration. When these materials are used for something useful, we call the same items recycled.
“We shouldn’t be putting any food residuals, so-called food “waste” in landfills,” Culhane says. “That’s ridiculous. When you put organic material in a landfill where the anaerobes are, they are going to fart out and belch out methane, and then we have no way to capture it.”
It is estimated that 20% of the anthropogenic methane emissions come from the “waste” sector. If you put organic material in a compost, including yard scraps, paper, cardboard, or other decomposable waste, you still produce methane but get local fertilizer.
“But if you put it in the biodigester,” Culhane recommends, “You’re containing all the possible methane that the food waste would’ve released in the landfill, in the garbage can, and the compost. You’re containing it all. And then we burn it.”
This act of burning does not contribute a significant amount of methane and CO2 since it is in balance. This is especially true if we’re not using fossil fuels to distort the growing of plants and animals too quickly by adding fertilizers and starchy foodstuffs.
“The rate of the biodigester and the use of it is in sync with what the system can handle,” Culhane says. “Just like methane is a product of methanogens, at the end of the day, we’ve got to get away from this divisive language and get away from thinking natural is good. Gas is gas. Whether it was from the compression and physical processes of hydrocarbons from dead plant material, dead animal material, or active living methanogens eating and producing it.”
When biogas is used for energy, methane emissions are indirectly reduced from avoided fossil fuel use. Preventing food waste throughout the entire food chain is also an important way to reduce methane emissions. Designing systems that can capture methane released from landfills would also be an important step. Some eco-villages and European countries are currently developing such systems.
Kenny Coogan earned a master’s degree in Global Sustainability and has published over 400 articles on pets, livestock, and gardening. He lives on a 1-acre homestead with chickens and ducks, managing a permaculture-style landscape. Coogan also runs a successful carnivorous plant nursery in Tampa. Listen to Coogan co-host the Mother Earth News and Friends Podcast by visiting https://www.motherearthnews.com/podcast/.
