To reach net zero organisations will have to remove, not offset, the emissions from the atmosphere that they cannot eradicate from their operations. Here we focus on carbon removal methods, specifically Direct Air Capture, and why those looking for net zero need to continue with reduction, but also invest in a carbon removal portfolio.
So we are talking carbon removal not carbon reduction? Yes. Even if we do everything else right on the path to reducing carbon emissions, the world still needs to remove up to 220 Gigatonnes of carbon from the atmosphere by 2050.
Hussein Dhanani head of sales and strategic partnerships, Climeworks, a carbon removal company based in Switzerland says: “The Science-Based Targets initiative (SBTi) states that in order to prevent the worst effects of climate change, we need to stay below 1.5 degrees Celsius. To reach net zero, we must reduce our emissions by up to 90 per cent and then employ carbon removal for the remaining 10 per cent.”
An Energy Transitions Commission report last year found CO2 removals could perhaps reach 3.5 Gigatonnes a year by 2030, at a cost of some $200bn per annum. If we are removing 3.5 Gigatonnes at year by 2030 we will still be some way off from that 220 Gigatonne figure.
What are the methods of carbon removal? There are many ways to remove carbon from the atmosphere – Mark Stevenson futurist and co founder of CUR8, a UK-based carbon removal company, says its scientists are currently looking at around 300 different ways to remove carbon, but only seven or eight of those processes have passed the test to make it into their removals portfolio – providing a best-available mix of speed of drawdown, durability of storage, societal and environmental co-benefits that are scientifically and legally verifiable.
Planting trees removes carbon from the atmosphere and it’s a good idea – with forests in the US capturing 12 per cent of carbon emissions – but a tree has to be quite mature to remove carbon effectively. If you are planting a virgin forest then, depending on the type of tree, the first 10 years that forest will be a positive carbon emitter and it’s only after 30-40 years the trees get the carbon removal going.
To remove carbon with a sense of urgency, there are other ways; such as enhanced rock weathering – carbon taken from the atmosphere binding with rock dust which can be used on farmland as natural fertiliser.
Using trees in construction (think cross laminated timber) keeps the carbon captured in buildings rather than released back into the atmosphere when they die. But this does have a durability issue considering buildings may only be standing for 60 years. So it’s not a permanent carbon removal solution although it can replace carbon-intensive materials such as steel and concrete.
Soil currently holds 2.5 billion tonnes of carbon (it’s the second biggest carbon storage mechanism on the planet after oceans). Moving to regenerative farming can quickly draw down carbon to the soil. The issue with that is, if the farmer dies or the farm changes hands what is to stop someone disturbing that process and releasing the carbon back into the atmosphere? However, approaches using microbes to rewild soil biomes show enormous promise – drawing down carbon in a far more durable form.
According to Cur8’s Mark Stevenson: “Getting carbon out of the atmosphere is not hard. Carbon is a chemically promiscuous element – it will bond with anything. Getting it to stay out is what my scientific team might call a ‘chemically recalcitrant form’ is more difficult.”
When you are removing carbon you have to think about several things simultaneously. You have to think about the method you’re using to get it out of the atmosphere and is it benign? You have to think about how quickly it comes out and about the durability of the storage of that carbon? And then you also have to work out how you verify that scientifically and legally.
Stevenson adds: “Direct Air Capture (DAC) does it really quickly. We are working with a company who, when they switch on the machine next year, will pull out a tonne of carbon every minute. It’s usually stored in a mineralised form, so the storage is on the millennial time-frame. And it’s pretty easy to verify and audit the drawdown. But, it’s massively expensive too.
What is DAC? Direct Air Capture technology uses chemical reactions to pull carbon out of the atmosphere and sequester it underground where it can stay for thousands of years.
Climework’s Dhanani says: “The science emphasises that achieving net zero requires not only reduction but also removal. The IPCC (Intergovernmental Panel on Climate Change) underscores this point. Within carbon removal, one of the methods is DAC, which stands out due to its permanence, additionality, and measurability. It’s also highly scalable. While DAC is a significant part of the solution, it’s essential to recognize that we will need every available method to remove carbon. DAC is undoubtedly a major component, but by starting early, you position yourself as a climate leader, aligning with scientific recommendations and future-proofing the supply for years to come.”
As mentioned, this technology does not come cheap. CUR8’s Stevenson says it’s around £1000/tonne of carbon removed, but that figure will come down as there is more buy in.
Three reasons why DAC should be on the radar
- We won’t reach net zero without carbon removal and DAC is a fast and permanent solution;
- Legally – the UK has a legally binding net zero target for 2050 which can only be reached by both carbon reduction and carbon removal;
- Commercially – the auditing journey to net zero will be much the same as financial disclosures but as CUR8’s Stevenson points out “at some point in the next 10-15 years you will be made legally responsible for you emissions and if you’re not on top of that you will lose your licence to operate”.
Where are the DAC facilities? There are 18 DAC facilities worldwide and 11 more in development, but even with all of these up and running they will only be able to remove 10 per cent of carbon emissions by 2050. At Climeworks’ facility in Iceland Orca, the CO2 is permanently removed from the air by capturing and geologically storing it for thousands of years with Climeworks’ storage partner Carbfix. Climeworks’ DAC facilities run exclusively on clean energy (they have to really as otherwise you are looking at huge heat and power inputs and removing, for example, just 1 Gigatonne of carbon dioxide from the air could be nearly 10 per cent of today’s total energy consumption).
The US government recently announced USD$1.2 billion for America’s first two DAC hubs in Texas and Louisiana. It will also take on 19 other projects to help with future DAC facilities.
Are there any in the UK? Lowestoft in Suffolk could be home to one of the UK’s first DAC pilot projects after planning permission was granted. If the pilot is successful the new facility would capture 1.5m tonnes of CO2 each year. That’s enough to offset nearly all of the UK’s emissions from rail travel. The Lowestoft project has had £3m of funding from the Government Greenhouse Gas Removal and could be operational from next year, although the pilot has been given two years to see results before a possible permanent full scale DAC facility is built. It would use heat generated from Sizewell C to extract CO2 from the air be at a different site to the Sizewell C site.
Do people have concerns about storing carbon underground? Carbon is a natural substance and not toxic. When it’s solidified it resembles marble as Climework’s Dhanani explains: “It was extracted to burn fossil fuels, and now we are returning it to its original source, storing it permanently in an effort to lock it away forever. Once it transitions from being a gas to a solid, it remains underground for over 10,000 years. Science guides our approach.”
Can’t we just concentrate on reducing carbon emissions and then come to carbon removal later? Not really. It’s a bit like a credit card bill. The longer you leave it the bigger the bill at the end. It’s great to reduce carbon emissions, and no one is saying to stop doing that, but carbon removal has to begin now ideally for any chance of reaching net zero. And unless the DAC technology and sector gets buyin, there won’t be the infrastructure there when people eventually want it.
Climework’s Dhanani says: “The next 10 years are critical for the DAC carbon removal companies because if they can’t get the buy in now, they won’t be able to build the facilities and put in the investment to deal with the demand when it eventually comes.”
How do we know carbon removal isn’t going to be shunned in the same way offsets are now finding themselves? All the laws on net zero around the world say you have to remove residual emissions – you can’t offset them, you have to remove them. There are arguments about when you do that, but looking at the science most would say start now.
Who is verifying carbon removal? Just as there are a lot of sustainable hotel certification bodies, there are a lot of verification standards and bodies evolving around carbon removal. And there are no universal standards.
CUR8’s Stevenson argues perhaps there shouldn’t be a universal standard as “it’s arguable that there shouldn’t be because for example trees in Scotland are not the same as trees in Madagascar. We go and look at the people who are doing the verification and how they are doing it – for example with soil carbon there are six or so bodies verifying it across the world. Some would argue that the Australian government is the most stringent one. What we do is make sure anything we sell you isn’t going to come back in the future to bit you in the ass. We can show an audit trail.”
Some ways of drawing down carbon haven’t made it to the market yet because they are so difficult to verify – a good example is marine carbon. Oceans hold huge amounts of carbon but creating a method and trying to verify that in that environment has proved hard.
Stevenson says: “With DAC machines it is really easy to measure. You can see the carbon coming out and any auditor or regulator can come in and see that and verify.”
What about carbon removal and the accommodation sector? James Fry founder Beyond Apartments, the UK’s first sustainable apartment group, says: “If we think of carbon like rubbish, we have built a huge rubbish dump, which we are all continuing to add to. We need to stop adding to it, while also reducing the amount of rubbish in the dump. The most important thing any individual and business can do is reduce first and then put our money into technology and innovation that enables us to take it out.”
Sustainable Hotel News reported in June this year of a hotel in Greece being one of the first to use DAC to be carbon neutral (see below) but the sector hasn’t been big on the uptake, concentrating on reduction first.
Climeworks’ Dhanani says: “We’ve started speaking to a few of them [hotels], but I think their focus today is largely on reduction, and they are putting in a lot of effort to reduce energy consumption and waste, which is absolutely necessary. What we are trying to explain to them is that while reduction is the top priority, in order to achieve net zero, you need to start early and think about carbon removal now. So, build a portfolio, listen to science, inspire others, and contribute to the growth of the industry. The next 10 years are critical.”
Is it too late to start investing in a carbon removal portfolio? The answer is of course it’s not too late to begin but it’s also, according to the removal companies, pretty imperative that companies start investing in removal portfolios now or there won’t be the infrastructure to support those who want to, and need to in the future.
Mark Stevenson says: “As our clients set reductions targets there is a point when you get to the residual emissions, so we build targets to remove that as well. Removing annually builds investment into the market to reduce the cost down the line. Doing both allows you to demonstrate a credible net-zero plan to your stakeholders and regulators.”
Dhanani adds: “Most of our partnerships are long-term, typically spanning 10 years. This approach provides them with long-term visibility and ensures a stable supply. Today, we cannot supply new customers until 2027, as we are constructing plants and working to meet growing demand. Scaling up to reach the billion target by 2030 will depend on more partners joining us.”