September 2008 Archives

Methane Time Bomb Update

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Following on its coverage of an expedition to Russia's northern coast that found methane deposits leaking through melting permafrost into the water and atmosphere, The Independent has news that a British expedition to the seas off the coast of Norway has discovered "hundreds of methane plumes".  From the article:

Yesterday, researchers on board the British research ship the James Clark Ross said they had counted about 250 methane plumes bubbling from the seabed in an area of about 30 square miles in water less than 400 metres (1,300 feet) deep off the west coast of Svalbard. They have also discovered a set of deeper plumes at depths of about 1,200 metres at a second site near by.

The story notes that "It is likely that methane emissions off Svalbard have been continuous for about 15,000 years – since the last ice age."  I think it is fascinating that these plumes have only just been discovered.  This means the methane budget of the atmosphere is probably still quite poorly understood, even as it is clear new sources of methane are opening due to climate change.

Cleaning out some bookmarks

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In no particular order of importance:

  • Metbolix has announced it has modified switchgrass to produce PHA.  The "Mirel history" page on the website suggests there are 7 enzymes in the pathway.  An independent Life Cycle Analysis of Mirel, "Conducted by Dr. Bruce Dale, professor of Chemical Engineering at Michigan State University, determined that production of Mirel reduces the use of nonrenewable energy by more than 95% and provides a 200% reduction in greenhouse gases (GHG) compared to production of conventional petroleum-based plastics. concluded."  (PDF Press release)
  • Here is an essay from Jeremy Haft (WSJ via Huffington Post) that opines the US has a permanent competitive edge over China.  Really?
  • A couple of posts from Wired on saving our economy with a cleantech/greentech bubble.  'Cuz bubbles really keep us afloat.  Until they pop.  And we write $700 billion dollar checks.  Right... 

"Methane time bomb"

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The Independent carried a story on Tuesday that should alarm anyone interested in climate change (anthropogenic or otherwise).

"Exclusive: The methane time bomb", by Steve Connor, describes a just concluded methane sampling expedition along "the entire length of Russia's northern coast".  Interested readers should just follow the link to get the whole story.  To summarize: warming waters are releasing so much methane from previously trapped deposits that in some areas the seas are literally foaming as gas bubbles up from below.  Previous sampling cruises in the area have detected increasing concentrations of dissolved methane in water, but apparently methane deposits are escaping at an increasing rate.  Here is a good number from the article to keep in mind: the arctic region as a whole has warmed 4 degrees C in the last decade.

Since the release is caused by melting permafrost, there isn't much we can do to stop it.  So, given that methane is a much more powerful greenhouse gas than carbon dioxide, we might want to give some thought to attempting a fix.

Jamais Cascio has been following this threat for quite a while, and extends here his thoughts on dealing with atmospheric methane using geo-engineering using bio-engineered microbes.

Jamais writes:

The most conservative estimates I've seen start at around 70 billion metric tons of methane -- the equivalent in greenhouse terms to 1.6 trillion metric tons of CO2. As a point of comparison, the total annual greenhouse footprint in the US is about 7 billion tons; globally, the annual footprint is about 30 billion tons.

If this methane leak continues to increase, we may be facing a disastrous result that no amount of renewable energy, vegetarianism, and bicycling will help. This is one scenario in which the deployment of geoengineering is over-determined, probably needing to remain in place for quite a while as we try to remove the methane (or, at worst, wait for it to cycle out naturally over the course of a decade or so). It's also a scenario that might require large-scale use of bioengineering.

That would be, to put it lightly, an extremely hard project.  And we are nowhere near ready to start.  Happy Thursday.

"Coskata Due Diligence"

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Oliver Morton at Nature pointed me to a bunch of excellent posts on Coskata by Robert Rapier at R-Squared.  Recall that Coskata wants to gasify cellulose and feed the resulting synthesis gas to bugs that make ethanol.  Here are Rapier's "Coskata"-tagged posts.

Among other points, Rapier makes some nice back of the envelope estimates of the technical and economic feasibility of Coskata's process.  In short, Coskata's claims appear to be consistent with the laws of thermodynamics, but perhaps not so much with the law of supply and demand, and their logistics challenges might border on being inconsistent with the consevation of matter.

Basically, it all, err, "boils down" to the fact that Coskata is probably going to get tripped up by their focus on ethanol and the consequent energy cost of separating ethanol from water.  Even if you have a nifty process for turning cellulose into ethanol, it takes a large fraction of the energy in the cellulose to purify the ethanol.  And it really doesn't matter whether you distill or use a membrane -- the entropy of mixing still hoses you even if you somehow escape the specific heat of water and its enthalpy of vaporization.

Now if you hacked the metabolic pathway that consumes synthesis gas so that the bug made something more interesting like butanol, or a gasoline analog, that either had lower miscibility or even phase separated, that would really be something because it would minimize the energy cost of purification.

Great work, Mr. Rapier.  And many thanks, Oliver.