From Wikipedia – Methane (US: /ˈmɛθeɪn/, UK: /ˈmiːθeɪn/) is a chemical compound with the chemical formula CH4 (one atom of carbon and four atoms of hydrogen). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure.
Methane is the main ingredient in natural gas. Methane is an odorless, colorless, tasteless gas that is lighter than air. When methane burns in the air it has a blue flame. When it undergoes combustion it produces a great amount of heat, which makes it very useful as a fuel source.
My earliest memory of methane was my teenage buddies lighting farts. This was done by holding a lighter near their butt holes while relieving flatulence. Not a pretty picture but it is a memory that sticks with me. Who among can say we never gave this a try? I don’t remember any direct injuries as a result but a flame in close proximity to skin can’t be the safest activity thought up by teenage boys.
Introducing methane into the conversation is important. Although it only represents about 20 percent of airborne gases and it lasts only about nine years, its warming impact over a 20-year period is 84 times that of carbon dioxide. There is consensus it is responsible for almost a quarter of global warming. To me, that means it is a much more dangerous gas than carbon dioxide. But the good news is given the short time it lasts in the atmosphere, it may be possible to reduce its impact more quickly than carbon dioxide and other airborne gasses bringing about atmospheric warming.
The main source of methane emissions is abandoned coal mines, oil and gas operations, and farming. Roughly sixty percent of methane is from human activities; including emissions from fermentation processes associated with livestock, from cultivated rice paddies, from fossil fuel use and biomass burning, and from landfills.
From when we started recording methane concentrations roughly 200 years ago, it has increased steadily. Since 2007, they have more than doubled. As with carbon dioxide, this is a direct result of human activity, and it is clear that the increase is well beyond what natural sinks can offset. So like carbon dioxide, there is a manmade imbalance.
Like the water cycle in which water evaporates into the air, returns to the Earth, and then evaporates again, methane behaves in the same way. There are numerous sources that release methane and also sinks or ways that methane is trapped (sequestered) or destroyed. The cycle beings in the soil where methane gas is created by microbes and consumed by methanotrophs, which are microorganisms that feed on methane. This is just one source and combines with emissions from landfills, livestock, and the burning of fossil fuels.
The main natural mechanism for the removal of methane from the earth’s atmosphere is oxidation within the troposphere by the hydroxyl radical. Okay, I have no idea what this is but apparently, it is a negatively charged oxygen atom bonded to a hydrogen atom. Still clear as mud to me but what counts is that hydroxyl radicals are a form of sink because they scrub the atmosphere clean of pollutant molecules and break them down. In an ideal world, methane sources would be balanced with methane sinks. As with carbon dioxide, however, the concentration of methane in the atmosphere is rising as a result of human activities.
Methane crystals, called clathrates (another new term for me), form in cold, oxygen-poor undersea sediments as well as being trapped in the permafrost which is the permanently frozen soil in the artic and subarctic latitudes. As the planet warms, these deep, cold sediments are melting and sending methane bubbling to the surface and emitted into the atmosphere.
So let me wrap this article on a positive note. As COP32, a handful of countries committed to reducing methane emissions. To my personal disappointment, Canada was not one of them but the recognition that methane needs comparable attention as carbon dioxide is a good start.
Reason for Hope – Totally Unrelated to Methane
A friend (Randy Barkhouse) sent me the chart below. It shows that the cost of renewable energy is dropping while that of fossil fuels is getting more expensive. That is very good news as it provides lots of motivation to spend on renewable energy sources. It doesn’t mean there is a solution right around the corner but it certainly creates a good argument that we are heading in the right direction. Hoorah!
The capital cost is just one aspect. We live in a world that has become tethered to fossil fuels so it will take time to retrofit. Personally, I want to be driving an electric car now!