Wednesday, May 14, 2008

Bacterial Farts

New Scientist Bloggers write about how we should be more worried about methane than we should be about carbon dioxide.

From the blog:
Methane is a potent greenhouse gas, warming the planet 25 times more, molecule-for-molecule, than CO2. It doesn't last as long in the atmosphere, which tempers its kick, but it's still enough to give you nightmares.

As Fred Pearce has reported, thawing Arctic permafrost could give off massive amounts of methane, which would warm the planet. Permafrost is basically frozen mud, and when it thaws, microbes start chewing it up, emitting both methane and CO2, the amounts depending on the temperature, how wet it is, and other factors.
If you want to track methane levels, you can click here on the NOAA link. To choose methane, under "Gas" select CH4.

Methane is produced by methanogens (methano - methane, gen - birth/generate), bacteria which generate methane as a metabolic byproduct. They're found in nature where there isn't much air (i.e., anaerobic conditions) and different types produce methane from different sources. Some use carbon dioxide to produce methane, others use longer chain carbon sources.

These are the same bugs used in anaerobic digestion to make methane that, when cleaned up, can be used as natural gas ... so they're definitely useful and can be used for practical applications.


Blake said...

Do you mean that methanogens could conceivably be cultivated to capture commercially usable amounts of natural gas?

Tom said...

Not only is it conceivable, it's already being done.

Bison Renewable Energy is one example.

Here is an article about it in the Siouxland Business Journal. They'll be using 11 1 million gallon tanks of manure to generate methane via anaerobic digestion. This technology is employed with regularity in Europe and is found on a small scale on farms all over the world. I should probably blog about it.

Oh, and thanks for stopping by. Excellent question too. :)

Tom said...

I should also note that, if your natural gas company talks about getting some of their gas from landfills (aka, "landfill gas") you're already seeing use of methanogens in your own daily life. Perhaps you've seen the commercials about the companies using landfill gas to run their plants (their name escapes me at the moment), but here a link to a report on GM using landfill gas to run their OKC operation.

Blake said...

Fantastic! The GM article points me in the direction of the next question on my mind, i.e. to what extent can this technique replace current consumption. It looks like a significant source already; could it become a primary source, largely or even completely replacing diminishing mined reserves?

Tom said...


I intend on answering this today in a blog post. Just to let you know I haven't forgotten. :)