Carbon dioxide (CO2—a single atom of carbon with two attached atoms of oxygen) gets most of the attention as the cause of global warming
because it can persist in the atmosphere for centuries. Methane is a
gas (CH4—a single carbon atom with four attached atoms of hydrogen)
that deserves attention, especially because every portion of a degree
is crucial in avoiding the worst consequences of global warming.
Although methane persists in the atmosphere for only about 20 years,
it is about 80 times more warming than carbon dioxide, so its
importance in the short term is critical. “Cutting methane is the
single most important strategy in slow near term warming,” says
Durwood Zaelke, the president of the Institute for Governance and
Sustainability (The Guardian Weekly, November 21, 2015). Its
pre-industrial atmospheric concentration was about 715 parts per
billion, and its 2025 level is presently measured at about 1930 ppb,
an increase of nearly 270%. Because of the short life of methane,
these high levels are maintained and increased by the continuous and
rising rate of emissions.
As a gas that is colourless and odourless, methane tends to be ignored
as a pollutant. However, it is emitted in huge amounts in the
production of oil, the extraction of coal, and leakage in the drilling
and handling of natural gas, including LNG—methane is the principal
flammable component of natural gas. An estimated 10% of methane
emissions come from agriculture—the flatulence of ruminates like
cattle, and from the decomposition of organic material such as manure
and sewage. The rotting of material in landfills also produces
methane, which can be collected and used as a supplement to natural
gas.
At the COP26 meeting in Glasgow, more than 150 countries agreed to
reduce their emission levels by 30% between 2020 and 2030, a measure
that would have a considerable effect on slowing the rate of global
warming. Unfortunately, the major emitters, India, China, United
States and Russia, were not signatories, and the US, under Donald
Trump, who even denies the basic science of climate change, is not
cooperating.
An analysis of methane production in The Guardian Weekly estimates
that capturing the escaping gas would be easy and inexpensive to do.
Indeed, capturing just one third would result in no net cost, since
the methane would have an estimated sale value of $1 trillion per
year.
As individual citizens, we can each help by electing politicians who
are cognisant of the methane problem. Governments can impose stricter
controls on the manufacture and distribution of natural gas and LNG,
and support the COP28 decision to “phase out fossil fuels.”—coal, in
particular, emits large amounts of methane simply by venting mines.
Government regulations can end coal mining, cap oil wells, curtail
fracking, and encourage the collection of methane from landfill sites.
Rotting forest debris creates both carbon dioxide and methane.
As individuals, we can also reduce our consumption of beef. As a food
source, cattle are inefficient and environmentally costly to grow.
Pastures displace forests, pollute waterways and use vast amounts of
water—about 1,542 litres is required to grow 100 grams of beef. About
60% of global farmland is used to produce beef, which supplies less
than 5% of the world’s protein.
As our planet warms, every fraction of a degree that can be avoided
will be immensely helpful. Reducing methane would be easy, effective
and cheap. Every little bit would help, and we certainly need help.
Ray Grigg for Sierra Quadra
Image Credit: Student setting methane bubbles on her hands on fire. (She dipped her hands in cold water first) – Photo by Scohen2017 (Own Work) via Wikimedia (CC BY 4.0)