How Much Global-Warming Methane from Food Waste?

Hey Mr. Green,

I think it’s been calculated what percentage of greenhouse gases from landfill are attributable to food waste. Our large senior apartment complex does not collect food waste from individual apartments (due to pest problems), but there’s more and more of this waste as increasing numbers of new residents only go to the dining room for one meal a day. We hope to find a way to combine individual waste with composting already done by our kitchen. Details of how bad it is for the world may help our case. —Mary, Oakland, California

Seems to me that the sheer volume of food waste is shocking enough in itself that it’s not even necessary to venture into the arcane calculations of methane from landfills (a method for which I’ll present later on). First, there’s the matter of sheer ridiculous volume: In the USA we presently dump about 33.5 million TONS of food “waste” into the landfills each year, or about 14% of some 240 million tons of stuff that goes to municipal dumps every year—and this doesn’t even count what zorks down garbage disposal units.

On top of this, garbage trucks burn well over 1 billion gallons of diesel fuel a year, according to a study by Inform, an environmental group that advocates for kinder, gentler garbage transport. So the food waste share is least 140 million gallons of fuel, and of course there are a lot of other pollutants emitted from diesel fuel.

Of possibly greater interest to you fellow seniors is another shocking discovery from Inform: there are twice as many garbage trucks as municipal buses in our country. Since many seniors are dependent on public transportation, they should be especially dedicated shifting resources from hauling garbage to hauling people.

Landfills in the United States contribute around 17% of our total global warming methane, which itself accounts for about 10% of the global warming gas generated in the United States, stated in terms of carbon dioxide equivalents. (Carbon dioxide from combustion accounts 83% of the total—so driving your car is still way worse than dumping food. While the volume of methane generated is only a fraction of  the volume of carbon dioxide, methane has 23 times the global warming potential, hence the effect of methane is stated in terms of how much carbon dioxide its effect equates to.)

Now to the complex calculations alluded to above. If you’re trying to determine the true global warming potential of your food waste, the actual volume of methane is only one part of a mighty complex scenario. A lot depends on how far away the dump and compost facility are from your town and how efficient the trucks are. Further complicating the matter is the fact that many dumps either just burn off the methane, which greatly reduces its global warming potential, while others actually run pipes through the dump that channel methane to be burned to run electric generators. A few even use their landfill’s methane to run their garbage trucks. (Mind you, while these solutions are technically intriguing, it would be way simpler to stop generating so much waste in the first place. While technically intriguing, using methane from waste in the landfill to haul waste to the landfill that didn’t need to land in the landfill in the first place seems to me a classic example of the growing absurdity of our economic system.)

Anyway, to find out what the score is in any given location, you have to start with a fair amount of investigation by contacting your local garbage haulers and landfill operators to get the details on trucking and landfill operations. If and when you manage to ferret out such data, you can then plug it into a calculator developed by the EPA to help municipal garbologists figure out the most cost effective and environmentally benign way to deal with garbage: http://www.epa.gov/climatechange/wycd/waste/calculators/Warm_Form.html

Yep, it’s your tax dollars at work, unless the right-wingers presently infesting Congress succeed in defunding the EPA in a nihilistic spasm that, as the poet Baudelaire said, “would willingly swallow down the earth.” OK. Enough politics, already. If any of you readers would like to undertake such calculations for your fair city, I would love to see the results of such dedicated citizen science, and thereby continue this discussion.

 

 

Comments

[Alicia]

Seems to me that the sheer volume of food waste is shocking enough in itself that it’s not even necessary to venture into the arcane calculations of methane from landfills