Is carbon removal a solution to the climate crisis?
Our friend Craig Cohon is ‘Walking it Back’ from London to Istanbul - 4000km (!) - to raise awareness about carbon removals and to influence local decision-making in cities he’ll stop in along the way.
He’s already removed his lifetime carbon emissions to date. You can learn about his journey here.
What is carbon removal?
No doubt about it, there is too much carbon dioxide in the atmosphere.
One solution is to limit the amount of carbon dioxide being pumped into the air (mitigation). However, despite lots of progress in this area, mitigation strategies alone are not enough to reach ‘safe zone’ targets.
Carbon removal may be the answer - i.e. removing the carbon currently in the atmosphere which remains from legacy emissions.
How does it work?
Bioenergy Carbon Capture and Storage (BECCS)
As the name suggests, BECCS burns biomass (read: plant material) for energy/heat/fuel and then captures/stores/repurposes most of the emissions given off as a result of that burning.
Commonly, the carbon dioxide is captured and then:
a) turned into a new material called biochar which can then be used to enhance soil health;
b) turned into hydrogen gas (clean energy) when burned with incomplete combustion;
c) injected deep underground where it can be stored permanently.
This process can be carbon negative since biomass absorbs carbon as it’s grown and is 100% renewable.
Direct Air Capture (DAC).
Direct air capture removes CO2 directly from the air and then stores or reutilises it. A large fan draws in air from the atmosphere and filters out the carbon dioxide. The filter inside the fan chemically binds with CO2 to remove it.
The carbon dioxide is then either stored permanently (in ways similar to those described above) and/or can be reused for commercial applications - e.g. for carbonating drinks! The remaining air (99.96%) is released back into the atmosphere.
Iceland already removes 4,000 tonnes of carbon dioxide every year and stores it in volcanic rock.
It’s not a perfect solution…
As with all solutions to complex problems, carbon removal technologies aren’t a ‘silver bullet’ against the climate emergency.
Some caveats to these technologies include (but aren’t limited to):
- Can carbon removal be used to legitimise ‘business as usual’ behaviour? The possibility of removing carbon could give a ‘free pass’ for large-scale emitters since their damage can be ‘undone’.
- Huge questions still remain surrounding justice and planetary health implications - huge amounts of space is needed to grow the biomass - will this lead to large swathes of monocultures and potential land grabbing from indigenous peoples and communities in the Global South?
- BECCS and DAC must be scaled to meet demand - this will cost lots of money. Will this funding compete with action on mitigation and/or adaptation?
- With BECCS in particular, could the carbon emissions needed to grow, harvest, transport and processing the biomass outweigh the amount of carbon captured?
What do you think about carbon removal? Do you think it’s a solution to the crisis? Let us know in the comments or on socials.
Part 2 on natural carbon removal or ‘carbon sinks’ coming soon!