Compost vs Landfill: Does it Really Make a Difference?
Last week I wrote a post about curbside composting programs that some cities have started. One of the benefits of keeping compostable food out of landfills, I wrote, is that it reduces landfill methane - a greenhouse gas that is 72% more powerful than carbon dioxide.
One of the readers, Dean, posed a question in the comments.
Does this actually reduce methane emissions? It seems, based on the lack of detail in the article, that the same amount of methane would be produced whether the organic waste was sitting in a compost pile or a landfill. Why wouldn’t that be true?
This is a good question, and I thought it deserved to be answered in a post instead of just a reply in the comments section.
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Landfill methane is a gas that is produced in a landfill because the things in the landfill undergo anaerobic decomposition. Basically, this means that because municipal solid waste that is buried in a landfill does not receive oxygen, it will produce methane.
A compost pile, on the other hand, undergoes aerobic decomposition. Because it is exposed to oxygen, either by turning it or through the use of worms and other living organisms, it produces CO2 (carbon dioxide) instead of methane.
Of course, not all compost piles are treated the same, so some attention needs to be paid to the compost pile to so that it receives the oxygen that it needs. But, if a compost pile is being taken care of properly, it will produce far less methane than a landfill.
This is a very basic answer, but I think it should answer the question as to why food waste is better off in a compost pile than in the local landfill.
Image courtesy of D’Arcy Norman on flickr
Kiashu - Touche! Very well done. However, I have read more than I care to remember about global warming and sincerely believe that a majority of the papers published during the last decade have focused on the warming effects of man-made CO2, not CH4. I will admit that I was being absurd in an effort to illustrate absurdity, and to pull someone into an expanded discussion. I do not claim any sort of victory. However, I do hope that others will learn that the scientific community is not in lock-step agreement on the issue of global warming. I see the greatest danger being the development of an environmental religion in which no one retains the ability (or the right) to think independently and swears an allegiance to some green high priest. After all, the global warming issue has in many arenas become less a scientific endeavor than a two-sided discussion about a belief system.
Two sentences in your last post do intrigue me:
“It’s impossible for us to have no effect on the world we live in.”
“We can’t hope to have zero impact on the environment, only to have a positive impact in some areas to balance out a minimised negative impact elsewhere.”
“The world we live in” continues to espouse the concept that man is a trespasser on earth who is separate from nature, rather than a being who is part of the natural world. Scriptures suggest that man was formed from the very soil of the earth, as opposed to being spoken into existence like the other beasts. Evolution suggests that all life originated from a single pool of ooze that just happened to contain two living cells that could reproduce. Since man has an arguable physical connection to the earth, maybe our purpose is to have a positive effect rather than no effect whatsoever. The problem is an inability to agree upon which of our actions can be deemed positive, negative, or downright damning.
As far as the topic of composting, I see no harm in choosing to compost or to landfill most organic wastes. However, the decision to do either should remain a personal choice.
Dear Joe
Thanks for your fascinating comment. INterested in the bursts of methane released when compost is turned. Am also doing a Masters on this. The IPCC has very little on this.
can I quote you? What’s your surname? Know of any figures or studies?
Some best practice landfill only releases 10% of the methane to the atmosphere. Could bad compost be worse?
Also, Robin, methane is not 72% more potent than CO2, it’s 72 TIMES more potent a greenhouse gas, over 20 years (or 23 times over 100 years because CO2 lasts longer). Thank you for raising this issue, it’s very important.
Joe’s comment was the best researched, but who are you Joe? Can we quote you?
-Barbara from Australia
Several issues here. First this ignores the fact that many landfills siphon their methane for energy and thus turn it into co2+ energy. Second I do not buy the whole C02 greenhouse gas argument. It to me reeks of alchemey. There is no more carbon in the world today than there has ever been, that is a fact of science. The issue is sequestered carbon. Your garbage that is composting was not sequestered. No matter what you do with it in the end it will release co2 be consumed by plants and put back into a carbon compound. We are spinning ourselves around chasing a system that has worked since the beginning of time and now all of the sudden is broke or harmful? As a farmer I know that plants would LOVE a Co2 system that is 3 times richer than what exists now. They would grow faster and produce more food or lumber. The CO2 arguement is false and it is causing us to ignore the true issues facing the environment now. We will waste millions to change something that is not broke and in return ignore real environmental issues that could not be fixed due to lack of funding.
Nope, please don’t quote me. There are lots of large studies on this in reputable scientific journals to use if you are writing a thesis which show what I am explaining. Please use your library and find them.
I completed my studies more than 10 years ago and spent some time working as a composting consultant, measuring and trying to understand various aspects of the industrial composting process.
Given this is a very small field, before long I had to find alternative employment. But as I said, if you are completing higher education, don’t take the word of someone online, check out proper peer reviewed papers.
[...] hazardous gases within is on the whole an untested proposition, seemingly inspired by the landfill model – out of sight, out of [...]
Thanks for this post, I was listening to David Sizuki on the radio talk about how we should all compost to reduce methane gas and this was the first question that popped into my head.
This has inspired me to talk to the building management about a compost setup for our building. We have a few gardens on the property and there is a really nice community garden directly across the street. I’m sure they’d take our heaps of rotten goodness
Cheers
With methane at 0.00017% of the atmosphere and CO2 at 0.038%, the whole thing is academic in comparison to water vapour which really is the main greenhouse gas and which cannot be modelled accurately. Because this major input cannot be properly accounted for, all models produce invalid conclusions.