We now have an idea of the different promising ways we could remove CO₂ from the atmosphere:
Planting trees
Blue carbon (coastal ecosystems)
Biochar
Soil carbon storage
Enhanced weathering
Bioenergy with carbon capture
Direct air capture
But when we put them all together, will they be enough? Will they be affordable? And will people, especially politicians, accept them?
Let’s have a look:
Comparing different carbon sequestration methods
How can we fund negative emissions technologies at the gigatonne scale?
There are two main ways to pay for carbon removal at this scale:
a government-based approach, with the revenue raised through carbon taxes; or
a market-led approach, based on the exchange of carbon credits.
So, what do these involve?
The government-based approach would involve governments paying for carbon removal, using money from a carbon tax .
Carbon taxes
A market-led approach involves the trading of “carbon credits” between CO₂ removers and emitters: CO₂-removers create “carbon credits”, which can then be bought by CO₂-emitters .
Carbon credits
Because every tonne of removed CO₂ is paid for by a tonne of emitted CO₂, carbon credits on their own won’t lead to global negative emissions - the best they can do is get us to net-zero emissions . If you want to know more about carbon taxes and credits, check out the Climate Economics course!
What about the social and environmental impacts?
Scaling up CO₂ removal to 1,000 GtCO₂ will require more than just money: widespread social acceptance will also be needed, as well as government regulations to limit the negative side-effects (such as competition for land, energy, and water, as well as risks to the environment and human health) .
There is the risk that CO₂ removal distracts us from working on actually reducing our carbon dioxide emissions . This means that if there are problems, we would have released damagingly high levels of CO₂ and have no way to bring them down…
In other words, it’s probably better to think of CO₂ removal as a backup plan, rather than something that means we can go on emitting greenhouse gases as normal.
Removal and reduction are both necessary
What are the alternatives?
If either emissions reductions or emissions removals aren’t as effective as we hope, then we will be heading for dangerous levels of global warming. If this happens, it might be time to consider radical approaches to limit these increasing temperatures. But can we really rely on such approaches? Let’s have a look in the final chapter…
