Methane is what most Natural Gas is. Usually as much as 99% of the “Natural Gas” is methane.
Any methane that gets in the atmosphere is said to be “fugitive” – where it doesn't belong.
We see fugitive methane as a big problem. It is said to create about 20% of global warming, but atmospheric levels have regularly been surprising. It seems like much more of a wildcard than CO2. When it enters the atmosphere, it doesn't have full effect until it reaches the upper atmosphere. At that time it starts with about 125 x the effect of the same weight of CO2. But, unlike CO2, Methane (CH4) gets broken down into CO2 and water by ultraviolet sunlight. This follows a half-life curve, and that means every half-life there is only half as much left. It's half life is approximately 11 years. So after 55 years, its strength has halved 5 times. 2 x 2 x 2 x 2 x 2 is 32, so it's strength would have decayed to 1/32 of it's starting strength. The strength ratio is called GWP and the number is filled in as average impact over a time period. So GWP(20) is about 86 and GWP(100) is about 28).
One way of thinking about this is that if we could quit emitting methane, it would only take a few decades for it to fade away to much less significance.
However, it isn't fading, it's increasing. That is a problem.
So, there are both biological sources of methane and fossil fuel sources of methane. Also, there is some ancient methane stored in the Arctic ocean as a gel caused by mixing it with cold water under pressure. That form is called a hydrate or a clathrate. Each of these has a slightly different mix of carbon isotopes. See isotopes_for_identifying_methane_sources
Our story on “ Renewable Natural Gas ”
We actually have control over several sources of methane:
The “Natural Gas” industry has not been careful enough with containment of their methane. See Fugitive Methane
Here are a list of pages that address more about methane:
|Caves left over from coal or methane extraction from the ground are sometimes sealed and refilled with methane|
|Identifying the source of fugitive methane can be done if you can measure it's isotope mix. NASA is beginning to do that from space.|
|The huge amounts of methane stored in the cold of permafrost and the Arctic Ocean floor have bubbled up in the past. If it happens, now, it's pretty certain loss of control, and extinction of most life forms.|
|If methane gets into the air, it has “gone fugitive”. We don't want that to happen.|
|Since methane is such a big deal, there is a constant stream of articles coming out about it.|
|Permafrost and arctic waters have already exhibited that they are starting to release methane…|
|It would simplify protecting the climate if we could just let methane fade itself away.|
|There are many possible tipping points. We often use the methane bomb as the example tipping point while explaining “The Precautionary Principle”|