There has been lots of discussion on Twitter recently bashing carbon capture because it will supposedly restrict the deployment of renewables somehow. Mark Jacobson of Stanford seems to be adament about this.
I disagree but I understand where the sentiment comes from. Carbon Capture and Sequestration (CCS) was originally proposed as a way to have “clean” fossil fuel power generation, mostly electricity generation. Fossil fuel companies (e.g., coal companies) supported this because it made it appear they were addressing the climate issue and, therefore, carbon capture research supported their “social license” to operate. It was a form of greenwashing.
But coal powered electricity production is no longer cost competitive with renewable power generation and adding CCS will only make coal less competitive. Natural gas (aka methane gas) is not far behind coal’s path.
So when faced with the option to add CCS to a coal or natural gas powered electricity plant, you should shut down the plant and replace it with wind and solar and storage (and storage equivalents such as demand-response).
So what should CCS be used for?
About 10 gigatons of CO2 per year (20~25% of all manmade emissions) comes from the industrial sector such as cement and steel production. While there are proposals for how to convert many industrial processes to low emissions, much additional R&D is needed and these conversions will take many decades. CCS can be scaled up this decade to capture emissions from existing plants, though we will need new CO2 infrastructure to move the CO2 to safe sequestration sites or send it to reuse plants making products such as “renewable fuels”.
And then there is removing CO2 directly from the atmosphere, which is called carbon dioxide removal (CDR). An example of CDR is Direct Air Capture (DAC) which are machines that absorb CO2 from the air. Planting trees is considered by some to be a form of CDR, but trees don't permanently sequester CO2. And when climate change starts to really get bad, those tress will die from flood, drought, wildfire, disease, bark beetle, etc. and release their CO2 back to the atmosphere. Another issue is that trees are sometimes darker than the land they cover so planting trees in certain places can actually increase warming.
Some people say that CDR/DAC is a “moral hazard” because it will somehow prolong the use of fossil fuels. It’s a bit like saying cancer treatments promote continued cigarette smoking. But, in any case, CO2 levels are already too high and are still rising so CDR techniques such as DAC will be required to meet climate targets such as limiting warming to +2ºC, which is probably impossible in a practical sense without CDR. Therefore, I claim that calling CDR a moral hazard is itself a moral hazard because the claim may delay the development and deployment of life/civilization saving CDR technologies.
Full disclosure: I’m a cleantech investor and I started investing in carbon capture a decade ago because I felt then that it would be needed to allow us to maintain a livable climate for our children. The events in the past decade have reinforced my belief in the necessity for carbon capture — not as a replacement for emissions reduction, but as a complement.