If you are worried about Global Warming Methane, it's great to know that methane is one of the greenhouse gases you as a composter can start to work to reduce. Let's have a look at the problem.
What is Methane?
Methane is a greenhouse gas formed when organic material decomposes without oxygen being present. It's chemical composition is CH₄. As a greenhouse gas methane is about 21 times more potent at warming the earth than CO₂.
That is the bad news. The good news is that global warming methane is relatively short lived and persists in the atmosphere for about 12 years. It is the principle component in natural gas so if we were able to carefully trap all the methane that's leaking into the atmosphere we could conveniently also provide ourselves with a relatively clean source of energy.
How Big a Contributor is Global Warming Methane to the overall issue?
According to the International Panel of Climate Change (IPCC) the effect on Global Warming of human generated greenhouse gases breaks down as follows:
So you can see methane or CH₄, is a significant player. The fact that is a short lived gas makes it an especially good candidate having a relatively quick effect.
Where does Methane come from?
Methane comes both from human activity and from natural sources. About 30% of Methane comes from natural sources - and most of that is from wetlands. The balance of 70% of methane production comes from human activities.
The breakdown worldwide on methane contributions is shown here in this pie chart. The biggest three contributors worldwide are:
Oil, Gas and Coal Mining
Enteric fermentation is science's way of describing a digestive process that results in serious gas. Cows are the biggest contributors and both ends have a crack at it - so it's the burps and farts of the grass eaters that give us the most methane world wide.
In North America the biggest contributors are:
Natural Gas Systems
Landfills account for about 24% of human generated emissions in North America and about 11% of world wide methane emissions.
As a Composting Gardener How Can You Help?
In Landfills methane is generated by the biodegradable waste doing its biodegrading. There are a few good strategies for coping with landfill methane:
Drill for gas in the landfill - in essence harvesting the gas instead of letting it drift up to the atmosphere. This has the added benefit of providing energy. Increasing numbers of landfills are doing this with many of them running small electrical generation plants off the methane. For the landfill methane already generated and lying in the fill this is a brilliant option.
Backyard or individual composting of as much food, yard and paper waste as possible for the individual. This has the benefit of reducing waste enroute to the dump and creating a valuable substance for use in a your gardens. It also has broader effects on the overall ecosystem.
Community Large Scale Composting of the biodegradables that make it to the landfill. These composting facilities can usually safely handle wastes that the average homeowner would have a tough time handling - things like dairy products, meats, bones, pet waste, etc. As well they are managed to maintain aerobic conditions eliminating methane production.
So for each of us we can have a small but every little bit helps effect on methane generation by taking care of our own compostable waste and a larger effect by banding together to develop a full composting program in our landfills.
Naturally we have a huge population of soil creatures waiting to both help and to receive our help. Not to mention all the other benefits...
And do not despair. Many brilliant minds are hard at work finding solutions for as many parts of the global warming methane, and overall climate change problem as possible.