Do we need carbon capture and storage?
We should not ignore CCS because it hasn’t been a success in the past, the author writes. Picture from Technology Centre Mongstad, where CO₂ capture technologies are tested and improved (Photo: tcmda.com).
I was provoked by a simple and innocent tweet, referring to an article on the pending death of carbon capture and storage (CCS). The article is fair enough and common talking points, but somewhat outdated. CCS has moved on.
I have been critical of CCS myself, particularly when linked to bioenergy (BECCS), though this does not mean that the technology is not needed. My problem is not so much CCS or BECCS, but the scale.
On the surface, CCS and BECCS does not make sense. Why set up a huge infrastructure to bury a waste, when we could simply decide to not emit the waste? We could just use renewables? (or not).
Yes, we need renewables, but there are good reasons why we also need at least some CCS. Here I give three reasons why I think we need to keep moving with CCS.
1. We need zero emissions
The cumulative emission relationship presented in the IPCC Fifth Assessment Report is a powerful way that show that to stabilise temperatures, at any level 2°C, 3°C, 4°C, requires zero emissions. Zilch.
Not a molecule of CO2 can be emitted, otherwise temperatures will rise. Indeed, this is approximately true for any long-lived greenhouse gas.
If we keep emitting greenhouse gases, temperatures keep rising!
While some argue we can stop emitting all greenhouse gases by using 100% wind, water, solar (100% WWS), such an approach may be infeasible and costly.
2. We need to remove carbon from the atmosphere
The need for zero emissions has rather profound implications. Think about this.
I usually think of three implications:
- It may be that we can’t remove all emissions from all sectors. Think methane from paddy rice, wetlands, or cattle, or nitrogen oxide from fertiliser use, or military, or aid work, or any number of difficult sectors.
- For equity reasons, we may allow some poor countries to continue emitting for a longer period.
- We have pretty much emitted too much already, we can’t get our act together, and we must undo the emissions of the past.
If any of these three implications hold, then we need to remove carbon dioxide from the atmosphere. Yes, this has some bad implications, but perhaps we need carbon dioxide removal anyway. We could also use solar radiation management.
We could do carbon dioxide removal in all sorts of ways, all have their pros and cons, and the most promising ones involve some CCS. We might use a little of all carbon dioxide removal options, which still means some CCS.
