Amplifying Short Term Pain
Steadily and incrementally, heat is building in Earth’s atmosphere and oceans. Our atmosphere is like a warm duvet wrapped around a sparkling blue gem, hanging in the cold darkness of space. In this duvet, the feathers are greenhouse gas molecules, trapping and retaining heat and keeping the planet warm. We tend to focus on carbon dioxide (CO2) as the primary agent of global warming, but methane (CH4) is also a significant player on the climate change stage. Methane is colorless, odorless, and invisible to the naked eye, but it is a super greenhouse gas.
Understanding its significance requires some knowledge of why it forms such a potent component of warming. Its most notable characteristic is its ability to absorb heat. Over short periods of a decade or two, methane’s warming potential is 87 times greater than CO2. Because methane’s lifespan in the atmosphere is short (about 12 years), its long-term heating potential over a century is lower at approximately 28 times that of CO2.
So, methane released today has a significant impact on meeting our temperature limiting goals over the next 30 to 40 years. Currently, methane constitutes about 10 percent of human-induced greenhouse gas emissions. However, about 25 percent of climate warming is estimated by the United Nations to come from methane released by human activity.
Methane’s life cycle
Methane, like CO2, is a natural component of Earth’s atmosphere. Both of these gases are essential components in making life on Earth possible. Without greenhouse gases, Earth’s average temperature would be about -18 degrees Celsius. We would live in a frozen world with most of the planet covered by a sheet of ice. Our attention to global warming is a Goldilocks’ scenario where one option is a little too hot, the next is a little too cold, and we want it just right. Our desire to keep the planet in the “right temperature range” has focused on controlling greenhouse gases. We don’t want to eliminate these gases, simply regulate them.
Both natural processes and human industrial activity produce methane. The bacterial driven decay of organic matter in low-oxygen environments, like the swamps and bogs of coastal wetlands, generates over 20 percent of the planet’s natural methane. In total, natural sources account for 52 percent of all global annual emissions.
Human activities, particularly agriculture and fossil fuel usage, account for the other half of all annual methane emissions into the atmosphere. The breakdown of Anthropogenic methane sources by percent of total annual emissions is:
Enteric fermentation (Cow burps) — 15%
Petroleum mining, transport, and usage — 11%
Landfills & waste — 9%
Coal mining — 5%
Rice Cultivation — 4%
Biomass and biofuel burning — 4%
When methane enters the atmosphere, it becomes an immediate agent of warming by absorbing heat from the sun and also soaking up radiant heat coming from the Earth’s interior. During its first decade in the atmosphere, it is 87 times more effective than carbon dioxide (CO2) as a warming agent. The good news is atmospheric methane breaks down after its first decade in the atmosphere. The bad news is it turns into CO2, which stays in the atmosphere for centuries.
But because methane has an oversized effect during its first decade in the atmosphere, it provides a clear target for limiting near-term temperature rise. A small cut in human-produced methane emissions has a disproportionately large effect in mitigating global warming.
Curtailing direct methane emissions is a clear focal point for reducing global temperature rise. One significant methane source from human activity is the mining, transport, and usage of fossil fuels.
Fossil fuels turning up the heat
Methane is colorless, odorless, and invisible to the naked eye, meaning that methane leaks are invisible under normal circumstances. However, infrared cameras can and do provide dramatic pictures of methane leaks from industrial activity.
Recent reporting from the New York Times documented significant methane leaks at multiple facilities in the U.S. Permian Basin, where oil and gas extraction is the primary industry. This petroleum basin spans 85,000 square miles and has over 265,000 active oil and gas wells. The Environmental Defense Fund estimates that 2.7 million tons of methane are released from these operations each year. This one basin accounts for about 3.5 percent of all petroleum related emissions worldwide.
In another example of unintentional emissions, a 2018 methane leak from a blowout at an Exxon Mobil drilling site in Ohio was only detected from space. Satellites detected the methane plume on the 13th day of the blowout, and by then, the methane release rate was approximately 120 metric tonnes per hour. The blowout lasted 20 days in total. This detected rate was nearly double that of the 2015 SoCalGas leak in Aliso Canyon, California.
Unintended consequences
Unfortunately, our problems aren’t limited to direct emissions from human activity. Rising global temperatures trigger feedback loops, causing increased methane release via geological and biological processes. One significant link is the connection between temperature and cellular metabolism. Higher temperatures lead to higher metabolic rates. If a lowly bacterium is chewing up decaying plant material, it will chew up more at higher temperatures. Of course, this process releases both CO2 and methane, meaning higher temperatures lead to more methane release. Even though this release is from natural sources, the increased methane emissions directly result from human-induced temperature rise.
Another side effect of higher temperatures is greater permafrost melt. Permafrost is rich in partially decayed organic material, and while these materials are frozen, they remain unavailable to bacteria. However, once higher temperatures thaw out the permafrost into a muddy, organic ooze, bacteria have a party and metabolize the newly available carbon, creating more methane.
Greater geological contributions of methane also come with higher temperatures. One of the natural storage pathways for methane is in clathrates or methane hydrates. A combination of cool temperature and elevated pressure allows the formation of an icy substance with lots of methane trapped in the ice matrix. These clathrates exist along seafloors and in permafrost. When temperatures rise, the clathrates may become unstable and release their methane payload. The current debate is mixed as to the magnitude of the threat represented by clathrate destabilization.
The near future effects of anthropogenic methane on global warming
Control of methane emissions is one of the most direct actions available for limiting global warming. Methane’s position as a super greenhouse gas means a little reduction goes a much longer way than reducing CO2 emissions. This is not an argument for focusing only on methane and ignoring CO2. Instead, it is an acknowledgment of the increased leverage methane reductions enjoy. The key areas of attack, ranked in order of current largest emissions, are:
Fossil Fuels (Coal and petroleum combined)
Enteric Fermentation
Landfills
Biomass/Biofuel burning
Rice cultivation
Leaving this task to individual companies and farmers is an ineffective way forward. National frameworks for controlling methane emissions will be required to meet the types of goals set in the Paris Agreement.
Read more on Medium publications:
Environmental Articles on EarthSphere
Stories, Life Observations and more on Dropstone
Read my recent fictional adventure on the origins of life
Sources:
Methane Tracker 2020 (Source: IEA) — https://www.iea.org/reports/methane-tracker-2020 Also:
Atmospheric Methane Levels Are Going Up — And No One Knows Why (By Jonathan Mingle; Wired) – https://www.wired.com/story/atmospheric-methane-levels-are-going-up-and-no-one-knows-why/ Also:
Unexpected Surge in Atmospheric Methane (Source: Climate Nexus) — https://climatenexus.org/climate-change-news/methane-surge/ Also:
Methane emissions from burning fossil fuels has been ‘vastly underestimated,’ study says (By Doyle Rice; USA Today) — https://www.usatoday.com/story/news/nation/2020/02/19/burning-fossil-fuels-emits-more-methane-climate-change-study/4798547002/ Also:
Human-caused emissions of methane from the extraction and use of fossil fuels may have been “severely underestimated”, a new study suggests. (By Robert McSweeney, Carbon Brief) — https://www.carbonbrief.org/methane-emissions-from-fossil-fuels-severely-underestimated
Environmentalists, industries are trying to find a methane solution (Source: PBS News Hour) — https://www.pbs.org/newshour/show/environmentalists-industries-are-trying-to-find-a-methane-solution
Methane: The other important greenhouse gas (EDF: Environmental Defense Fund) — https://www.edf.org/climate/methane-other-important-greenhouse-gas Also:
What Is Meth., Anyway? (By Jennifer Leman; Popular mechanics) — https://www.popularmechanics.com/science/environment/a28858699/what-is-methane/ Also:
Meth., explained (By ALEJANDRA BORUNDA; National Geographic) — https://www.nationalgeographic.com/environment/global-warming/methane/ Also:
What Types Of Electricity Sources Are Generated In The US? (By Ebony Porter; Direct Energy Blog) — https://www.directenergy.com/blog/types-of-electricity-generated-in-us/ Also:
It’s a Vast, Invisible Climate Menace. We Made It Visible.(By Jonah M. Kessel and Hiroko Tabuchi; New York Times) — https://www.nytimes.com/interactive/2019/12/12/climate/texas-methane-super-emitters.html Also:
Catastrophic Ohio Meth. Leak Stayed Hidden Until a Satellite Found It (By Rafi Letzter; Space.com) — https://www.space.com/giant-methane-leak-exxon-pennsylvania.html Also:
The Global Methane Budget 2000–2017 9Source: Earth system Science Data) — https://essd.copernicus.org/articles/12/1561/2020/essd-12-1561-2020.pdf
Cows Belch Methane, So Does the Earth (Source: ArcheanWeb) – https://archeanweb.com/2020/09/11/cows-belch-methane-so-does-the-earth/
Feature Image: Seafloor Methane Seep (Modified by ArcheanWeb) – Original Credit: By Authors of the study: Andrew R. Thurber, Sarah Seabrook and Rory M. Welsh – https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1134#d1e388, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=93592027