Swiss climate scientist: CO2 removal is tricky but essential

Initiatives to remove carbon dioxide (CO2) from the air are faltering – not because they don’t work, but because we fail to see opportunities and lack vision, says Swiss climate scientist Cyril Brunner.

Imagine a single company removing one million tonnes of CO2 from the air in 2030 – one-thirtieth of Switzerland’s current domestic emissions – and achieving this at less than $100 (CHF82) per tonne in the future. These two outlooks appear in almost every pitch deck of a CDR start-up (CDR stands for carbon dioxide removal or negative emissions technologies). To give this some perspective, at $100 per tonne, removing the CO2 from burning one litre of petrol would cost CHF0.31.

But without such ambitious targets, it is almost impossible to get funding for these kinds of projects. Investors and those seeking funds are likely aware that these scenarios are unrealistic. Whether it is strategically wise to underwrite them anyway is questionable, especially in a nascent sector in which public trust is still lacking.

This is currently the case at the Swiss start-up Climeworks, where two of their 19 facilities have fallen short of expectations.

Nevertheless, the ambitions reflect society’s wishes for CDR. What follows is an endurance test for a sector without which we cannot become climate neutral.

Driven by goodwill, not market logic

Our first challenge is that, as a society, we neither recognise the true cost of emitting a tonne of CO2 nor do we experience its effects when it is emitted. CO2 has a global impact that lasts for thousands of years. A recent studyExternal link by the Swiss research office Infras puts the average climate cost rate at CHF430 per tonne (2021 figure). If the burden on future generations were given greater weight, this figure would be around four times higher. Yet in many sectors we pay little or nothing today when we emit CO2. Therefore, paying someone to remove CO2 from the air is typically only a voluntary gesture of goodwill. To become a climate-neutral society, this must fundamentally change. It would require a legal framework – like the one we in Switzerland introduced 54 years ago for wastewater, and later for trash.

Most people would prefer if CO2 removal were free. Hence the unrealistic outlook of $100 per tonne. But removing CO2 from the atmosphere and storing it permanently is complicated and expensive. Depending on the technology and degree of maturity, CDR currently costs between CHF300 and CHF2,000 per tonne. Although these amounts are likely to decrease with technological advances and economies of scale, it is already clear that CDR will remain the most expensive part of a climate-neutral society. It is like a rubbish collection service for the emissions we cannot avoid and continue to dump into the air.

Just a drop in the bucket

The prevailing view is that first we must reduce emissions and only later worry about CO2 removal. According to this logic, every franc and every sustainably generated kilowatt hour of electricity should go towards reducing emissions rather than paying for CDR. Last year, $4 billion was invested in CO2 removal worldwide, just 0.2% of total investments in net-zero infrastructure.

Critics point out that companies like Climeworks currently filter out only a few hundred tonnes of CO2 from the air. But in a climate-neutral future, we will need to cut emissions by 85-90% and use carbon removal to offset the remaining 10-15%. Scaling up to billions of tonnes will not happen overnight. Rather than dismissing current efforts, it would be more constructive to acknowledge the need for ongoing emissions reduction, while simultaneously increasing investment in CDR.

To date, around 80% of global demand and investment in CDR has come from the United States. Under former President Biden, the US aimed to position itself as a global leader in this emerging economic sector. Three years ago, Climeworks was one of two companies awarded a major contract to build a CDR plant in the US. It hired around 350 additional employees for the project. Now, the Trump administration is reviewing whether to cut the $1 billion in federal funding commitments and, as a result, Climeworks has been forced to lay off staff. The job cuts did not come as a surprise given the circumstances, and difficult times likely lie ahead for other CDR companies.

For critics, this shift has confirmed what they believed – that CDR is not a viable solution. But they are mistaken – CDR does work. What prevents it from scaling is not technical failure, but our continued refusal to acknowledge the true cost of emitting CO2 and the effort involved in cleaning it up.

Nothing about this is easy

Many aspects of CO2 removal are counter-intuitive. To begin with, its necessity is not immediately obvious. For example, removing CO2 will always be necessary to compensate emissions from food production. We tend to forget that some emissions like these are unavoidable, and no amount of solar panels or nuclear power plants can solve this problem.

Second, more technology can sometimes be better for nature. Natural ecosystems are under immense pressure. Rather than optimising them purely as CO2 filters, we should focus on protecting and restoring them. These forests, soils and other ecosystems will contribute to CO2 removal, but not at the scale we need.

Third, even with massively reduced CO2 emissions, the amount of CO2 we will need to remove is staggering. Fourth, it can make more sense to remove less CO2 now but invest in scalable methods – even more expensive ones – that will deliver greater results in the long term.

Fifth, trial and error is an inherent part of innovation, even if it contradicts society’s expectation of instant perfection. Climeworks was transparent about the challenges facing its CDR installations in Iceland, which deliberately conducted tests in the harsh climate there. That transparency helps build trust – but also made the company a target for some, who wrongly blamed technical issues for job cuts, overlooking the underlying geopolitical and financial causes.

The CO2 removal process is difficult, its use is counter-intuitive, and yet its necessity is inescapable. It works technically. But for it to scale effectively, society must recognise the true costs of climate damage, seize the opportunities, and trust those who are developing solutions. Walking the tightrope between conflicting expectations and reality – of building a new global sector in a short space of time – is only possible if policymakers, industry and the public rally behind the pioneers who are leading the way.

Adapted from German by David Kelso Kaufher/vdv

The views expressed in this article are solely those of the author and do not necessarily reflect the views of SWI swissinfo.ch.