I've been a skeptic on Carbon Capture and Sequestration (CCS). After today's tutorial at Stanford's GCEP, I remain skeptical, but open to the idea that at least some part of our population should continue to work on the problem even if the solutions today are prohibitively expensive to be a true solution. Professor Sally Benson laid out a compelling case for CCS research. Carbon dioxide in the atmosphere causes ocean acidification, which negatively impacts the growth rate of organisms at the bottom of our food chain. If we do not get below 350 parts per million of CO2, then we risk runaway climate change. Since energy demands are "up and to the right," and we need negative emissions to reach 350 ppm, we must investigate CCS.
The thought of a time-bomb of underground carbon is unsettling. Professor Benson's contends that utilities have been storing natural gas as part of business as usual, and we can use these underground storage sites to store our CO2. Apparently we have enough suitable storage sites to allow us to perform CCS for a hundred years. Or up to 1000 years if we consider saline aquifers as suitable storage sites.
There are a few gaping troublesome spots though. The only solution to underground water contamination seems to be avoiding water tables altogether. This may be a good short term solution but the ground layers can shift. In addition, the cost of CCS, typically at 50-100% of the electricity cost, is cost prohibitive. At that price we can put in wind and solar infrastructure instead of investing in a new coal plant. Since today's CCS technology can only sequester carbon from high concentration outputs such as the tailpipe of a power plant, it seems cheaper to simply retire carbon intensive powerplants and build new ones based on wind, solar and nuclear.
But the reality of negative emission need remains. So CCS is probably sticking around. Or perhaps a twist of CCS can address the cost barrier, such as these companies working on recycling of CO2.