The heat is on for greenhouse gas methane - Reuters

[Eugene]

Source: Reuters

The heat is on for greenhouse gas methane
Sun Apr 29, 2007 9:13PM EDT

By David Fogarty

BANGKOK (Reuters) - Across the globe, chickens and pigs are doing their
bit to curb global warming. But cows and sheep still have some catching
up to do.

The farm animals produce lots of methane, a potent greenhouse gas that
gets far less public attention than carbon dioxide yet is at the heart of
efforts to fight climate change.

-snip-

Methane concentrations have increased about 150 percent in the air since
1750 and now far exceed the natural range of the past 650,000 years, the
U.N.'s climate panel says. And human activities are largely to blame.

The panel will be focusing on ways to curb methane and other greenhouse
gas emissions when it releases a major report on mitigating the effects of
climate change in Bangkok in early May.

-snip-

Read more: http://www.reuters.com/article/scienceNews/idUSSP14117220070430

[Dogmudgeon]

1. Biofuel methane is carbon-neutral, but not cowfart methane

Does the particular use of the methane confer some magical alchemical property?

Once upon a time, I stated that biofuel methane would have a significant, but not overwhelming, greenhouse gas effect, and got flamed for it. In the interim, it has been decided that animals raised for food are major sources of greenhouse gas.

All methane is CH₄ -- right?

:shrug:

In the words of The Robot from Lost In Space, "That does not compute".

--p!
Ban coal, not cows!

[kurth]

2. People should eat more veggies

and less cow.

[Dogmudgeon]

5. (See my post #4, below)

Thanks,

--p!

[Eugene]

3. Biofuel methane is mostly burned, not released into the atmosphere,

and is renewable. Since it replaces fossil fuels, it is at least
theoretically "carbon neutral." Methane in the air is a GHG.
Methane in a tank is fuel.

[Dogmudgeon]

4. Same Problem, Different Fuel

I'm not trying to start a fight here, but it's the same problem. The use of any fuel automatically puts it into the air. Better methane than gasoline, but the principle is the same and the cycling time is a few decades instead of 90 million years.

One molecule of methane, when burned with oxygen, should yield one molecule of carbon dioxide (CO₂) and two of water vapor (H₂O). That takes four molecules of oxygen out of circulation, at least until solar UV light can dissociate the molecules. This actually sounds worse than it is, and the process is common in nature. I consider liquid, portable fuels like methane, alcohols, and similar simple hydrocarbons to be greatly preferable to petroleum. But as long as we burn hydrocarbons for fuel, we will produce greenhouse gases. Ditto that for cultivating a food chain, especially with the wasteful practices we employ.

(Since I am quite rusty in chemistry, I invite the chemists here to check "my" reaction equation:
CH₄ + 2*O₂ => (combustion) => CO₂ + 2*H₂O
Non-technical readers, note: oxygen in nature occurs in pairs as O₂.)

Recently there has been a big push to blame a lot of global warming on animal husbandry and non-vegetarianism. This is essentially a lifestyle-political effort; factory farming in all its manifestations is ruinous, and singling out the production of meat is just as likely to lead to overlooking other bad practices in the production of "veggies". The reform of agriculture and food production is even more vital to our long-range survival than phasing out incandescent light bulbs.

As with all my arguments about nuclear energy, Peak Oil, transportation, food, finance, and the nature of modern civilization, I see these as complex webs of problems that can't be solved by sloganeering or political partialism any more than the single-source "tech fixes" that good lefties abhor. We could vote Democratic or Naderite, but without having a comprehensive plan to remedy our situation, we'll just be shifting the locus of blame. And we could all Go Vedge until we piss chlorophyll and it's not likely to do much except kill fewer ruminants and more rodents.

No particular "solution" will solve anything; the solution will be a change in the overall creative efforts (in the broad sense) of all people. It won't be a matter that we'll get biofuels, or not; nukes, or not; vegetarianism, or not; socialism, or not. Most likely, what we'll get will be an idiosyncratic set of "solutions" that fit our planet and culture, the result of two or three generations of trial-and-error, informed argument, and hard work.

--p!

[Eugene]

6. The general idea of biofuels (in theory) is the carbon/CO2 is recycled.

Yes, burning fuel produces CO2, but in biofuel, that carbon
came from CO2 captured by plants. That's what makes it
"carbon neutral." Methane from biomass comes from the
plants too. If biofuels work right, continued production
will not introduce new CO2 into the atmosphere.

At additional benefit of consuming biomethane is that you
are removing a greenhouse gas 23 times as as potent as CO2
from the atmosphere. If biomethane as fuel is done right,
it reduces net growth in both greenhouse gases.