Here's a new one for me, landfill food waste contributes up to 8% of AGW gasses.

[joshcryer]

Sorry I can't find an editorial of this (on the first two pages of google), so I can only post the abstract:

Landfill gas emissions are one of the largest anthropogenic sources of methane especially because of food waste (FW). To prevent these emissions growing with world population, future FW best management practices need to be evaluated. The objective of this paper was therefore to predict FW production for 2025 if present management practices are maintained, and then, to compare the impact of scenario 1: encouraging people to stay in rural areas and composting 75% of their FW, and; of scenario 2, where in addition to scenario 1, composting or anaerobically digesting 75% of urban FW (UFW). A relationship was established between per capita gross domestic product (GDP) and the population percentage living in urban areas (%UP), as well as production of municipal solid waste (MSW) and UFW. With estimated GDP and population growth per country,%UP and production of MSW and UFW could be predicted for 2025. A relatively accurate (R 2 > 0.85) correlation was found between GDP and%UP, and between GDP and mass of MSW and FW produced. On a global scale, MSW and UFW productions were predicted to increase by 51 and 44%, respectively, from 2005 to 2025. During the same period, and because of its expected economic development, Asia was predicted to experience the largest increase in UFW production, of 278 to 416 Gkg. If present MSW management trends are maintained, landfilled UFW was predicted to increase world CH4 emissions from 34 to 48 Gkg and the landfill share of global anthropogenic emissions from 8 to 10%. In comparison with maintaining present FW management practices, scenario 1 can lower UFW production by 30% and maintain the landfill share of the global anthropogenic emissions at 8%. With scenario 2, the landfill share of global anthropogenic emissions could be further reduced from 8 to 6% and leachate production could be reduced by 40%.

http://wmr.sagepub.com/cgi/content/abstract/24/5/421

But all is not lost:

Greater economic activity and a wider economic gap between rural and urban areas is leading to accelerated urbanisation and the generation of 35% more Urban Food Waste (UFW) from 2007 to 2025. Besides landfilling, this paper examines the advantages of introducing onsite composting and anaerobic digestion for the environmental recycling of UFW and the lowering of handling cost. For Asia and Africa, these solutions for UFW could reduce the mass of MSW by 43% and 55%, respectively, thus help there cities manage almost all of their MSW. For North America and Europe, such practice could reduce earth warming trends.

http://inderscience.metapress.com/app/home/contribution.asp?referrer=parent&backto=issue,1,12;journal,4,11;linkingpublicationresults,1:120365,1

[Xipe Totec]

1. I don't understand how composting food waste will reduce green house gases

Composting produces green house gases too.

[joshcryer]

2. Composting produces CO2, methane is a much stronger greenhouse gass.

Composting can be made to fit within the carbon cycle, so there needn't be net emissions from it.

[NNadir]

3. Actually, composting produces methane as well as CO2.

What happens in landfills is not qualitatively different than what happens in compost piles.

I touched on a related topic on another website:

http://www.dailykos.com/story/2008/1/22/18510/1895">Constructed Wetlands in Norway: Greenhouse Gas Implications.

[joshcryer]

4. Landfills are highly compacted and low in oxygen, so anaerobic bacteria proliferate.

You can utilized composting methods that keep bacteria alive that produce more CO2 than methane. It's all a matter of keeping it aerated. (There's a reason old time farmers shift through their compost, it's to oxygenate it.)

[XemaSab]

5. Compost releases some greenhouse gases

but compost can also be a good means of sequestering carbon.

The way I see it is that the CO2 was originally taken up by the parent plants and sequestered in organic matter.

We can either keep that OM in sequestered form, or throw in in a landfill for who know what fate?

[izquierdista]

6. You can get more use out of it

Food for human consumption that gets landfilled is highly inefficient. If it was diverted to the pig or poultry farm, it could get turned into animal biomass (useful) and shit which could be turned into biogas (also useful). But in the landfill, it anaerobically digests into half CO2 and half methane, and percolates up into the atmosphere.

It's a given that a lot of that carbon starting out as food is going to end up in the atmosphere. How useful it is along the way and whether it ends up as methane or CO2 are important questions as well.

[joshcryer]

7. When I was growing up part of our regular rituals was to turn the compost heap.

Turning it allowed oxygen to enter and it made it compost much quicker. Granted, I learned later on that simply poking holes in the compost would allow for enough oxygen to enter, but still.

[Dead_Parrot]

8. And that's not including the energy to grow & transport all that waste

The whole system is fucked. :(

[OKIsItJustMe]

9. Many landfills are now using their methane to produce energy

http://www.epa.gov/lmop/proj/index.htm

As of December 2008, approximately 480 landfill gas (LFG) energy projects were operational in the United States. These 480 projects generate approximately 12 billion kilowatt-hours of electricity per year and deliver 255 million cubic feet per day of LFG to direct-use applications. EPA estimates that approximately 520 additional landfills present attractive opportunities for project development.

This is a clear advantage over letting all of that stuff sit in unturned compost piles.

[joshcryer]

10. That's awesome.

[Dead_Parrot]

11. Quibble...

Not with you though: It always makes me twitchy to see landfill gas described as "renewable" - sort of implies we aren't going to change our habits at any point in the future.

Which we probably aren't, of course, but it still makes me twitchy...

[joshcryer]

12. Looks like they tap older landfills, not new ones.

The methane is going to escape from those landfills anyway. Obviously in the future we should be better at handling our waste (no more landfills), but this is a good solution.

Also, it seems less energy intensive than composting, since you will be constantly turning the compost, and oxygenating it if you want to minimize methane out gassing.

The more you know. :)

Found this too, while I was searching: http://www.ashdenawards.org/winners/arti06

Man humans are awesome, even if we do mess up the environment.

[Nihil]

13. Sounds like a good move for the old landfills.

It will prevent the fire/explosion risks (if properly done) and provide
fuel for local consumers.

:thumbsup:

PS: Can you please re-post that bit about the award winner as a new thread?
I love things like that where several problems are solved at once by a bit
of applied headwork!

:woohoo: