He doesn’t bite.
The first bloc of today’s presentations were about carbon capture and sequestration. Fascinating stuff.
The first presenter, from the Carbon Mitigation Initiative, presented a “stabilization triangle” model. Carbon emissions in 2004 were estimated to be 7 gigatons/year. On the current path, it’s expected to be 14 Gt/y by 2055. Stabilizing output would require finding seven wedges, each “wedge” equivalent to 1Gt/y of reduction somewhere. For example, increasing nuclear power generation 3x, wind 50x, or solar 700x would each generate a “wedge.” By combining many strategies, using technologies that exist today, the CO2 output could be stabilized.
There was some side discussion that we’re trending towards 21Gt/y. In 2006, emissions were ~8Gt/y It’s estimated 800 coal power plants (because coal is cheap) will be added in the next decade (China: 500, US: 100). Each 750MW coal power plant produces 5Mt/y.
One of the methods proposed for making power plants “carbon neutral” is to pump the CO2 back into the ground: coal beds, sub-sea sediments (that Sally sells by the seashore?), deep saline aquifers, and depleted oil fields.
Another option mentioned in Wired, is to add small amounts of iron to ocean water, stimulating phytoplankton that then convert CO2 into solid, harmless carbon. It’s an intriguing idea, though met with some skepticism. Plankton also consume NO3 and PO4 that could throw the marine ecosystem off for a few tenths of a gigaton of Carbon.
There was an amazing presentation by Jeff Bielicki (older copy linked) taking an economic view. With a model of locations that would suffice for deep sea sediment storage, he came up with a model for how a distribution network might look. The topology bore a striking resemblance to a computer network, where smaller facilities feeding into larger pipelines. He also considered the costs of routing (through a national park == expensive, along highway == cheaper). Then, he simulated the economies of scale. based on location and size of network. The unit cost of this model was hovering in the mid-$50/t.
The last presenter was advocating wood burial as a method. The premise was decomposition of fallen trees causes production of greenhouse gases. By digging a huge hole and burying the detritus, a carbon sink would be created. Benefits cited:
- Fire suppression by burying fuel
- Low technology, can be done in third-world countries
- Easy to monitor
- Easy to stop or reverse
- If expanded across all forests, it could generate a sustainable reduction of 10Gt/year:
- Tropical forests: 4.2Gt/y
- Temperate forests: 3.7Gt/y
- Boreal forests: 2.1Gt/y
To achieve this reduction, there’s a lot of digging and moving stuff into holes. A 10m x 10m x 25m hole holds 500t in a small surface area. A five person crew could dig this in a week using low technology methods. Faster if they have helicopters. (I swear he said this and threw up a slide with a picture.) Scaling this up would require one hole every 3 seconds, which amounts to 200,000 crews or one million workers.
There are “some issues.” (Oh, my, I don’t know where to even start.) Enough research has been done.
The second part of the day had lectures from IPCC working group chairpeople. That will be the subject of a future blog entry. It’s not a cheerful forecast.
Feeling totally bummed, I went back downstairs to the exhibit hall to buy my sand dollar:
On the way out, I ran into some friends who insisted on dragging me to Chinatown for some delicious orange beef and my annual bottle of beer (TsingTao). The buzz at half a bottle (or maybe it was just from looking at the label, I have such a low alcohol tolerance), good company and hilarious waiter helped my mood.