Climate scientist: overhyped carbon removal risks delaying urgent climate action

Misrepresenting the potential of novel carbon dioxide removal technologies like direct air capture (DAC) does not just squander investment, it risks undermining global efforts to decarbonise, says climate scientist James Kerry.

All the indicators of human caused climate change, including greenhouse gas concentrations and record-breaking global temperatures, are still going upExternal link, while the amount of carbon dioxide (CO2) we can still emit to keep warming to 1.5° degrees Celsius is shrinking at an alarming rate. Although we are not on track to fix this problem, the path to solving 90% of it lays before us should we choose to follow it. For example, the G20 countries that are responsible for generating 87% of all energy-related CO2 emissions could produce enough renewable energy for the whole world by 2050External link.

In roadmaps to reach net zero, meaning we no longer add more greenhouse gases than we take away, carbon dioxide removal technologies are assigned an important role. This includes addressing legacy emissions (pollution that’s still heating the planet) and so called hard-to-abate emissions. In reality, many supposedly hard-to-abate emissions are instead expensive-to-abate, for example, almost all the high-heat processes in heavy industry could be done with electricity, except that at present burning fossil fuels for heat is cheaper.

This problem was pointed out in a recent Swissinfo opinion piece by Cyril Brunner; “in many sectors we pay little or nothing today when we emit CO2”.

As long as the true cost of emitting CO2 is ignored, many industries will continue to claim their emissions are “hard-to-abate”. Successful decarbonisation requires both carrots and sticks, including accelerated investment in efficiency, renewable energy and storage, smart grids and electrifying everything we can. Combined with a price on carbon based not on the energy markets, but rather its true social and planetary cost: the damages it imposes on health, ecosystems, food systems, and future generations.

Based on current decarbonisation efforts, Dr Brunner is right to say that “the amount of CO2 we will need to remove is staggering” but he is wrong to suggest that carbon removal technologies like direct air capture (DAC), which filters CO2 from the air, can meet this need. To date, the DAC industry has sequestered around 10,000 tonnes of CO2, which is equivalent to about nine seconds’ worth of annual global emissions, less time than it takes to read this sentence. Reaching climate relevant scales of removals would mean scaling up the industry, in a matter of decades, by orders of magnitude that are unprecedented in industrial history.

DAC also faces some fundamental, inescapable headwinds that will not simply be resolved by trial and error. In the atmosphere, CO2 still accounts for a very small fraction meaning vast amounts of air must be processed. This consumes a lot of energy, which itself must be fossil fuel free for the process to make any climate sense. And DAC alone does not actually remove CO2; the captured gas must still be compressed, transported and injected underground. This second phase has so far also proved underwhelmingExternal link and fraught with risks, ranging from potential leakage to induced seismic activityExternal link, including earthquakes.

Contrary to claims made, funding is not the issue here. While DAC companies are not very good at sucking up carbon dioxide, they have proven far more effective at capturing investmentExternal link. Swiss-based DAC company, Climeworks, is a good example.

They have received around US$800 million in funding since they began operating 16 years ago and have not even managed to recapture their own annual operating emissionsExternal link. But debates about the amount of funding going to carbon removal miss the key point: overpromising on technologies like DAC poses real risks both in terms of undermining decarbonisation efforts now and in leading to unrealistic plans to reach net zero.

Pre-selling carbon credits is one way in which such companies engender false expectations that can undermine real climate action while offering the purchasers a fig leaf for unfettered emissions growth. Microsoft, SAP, Morgan Stanley and Tik Tok, for instance, have all purchased DAC credits while their emissions, which are not truly hard-to-abate, continue to rise.

Perhaps more pernicious still are the ties between the fossil fuel industry, petrostates, and carbon removal firms, particularly in the DAC sector. The CEO of Occidental Petroleum has described DAC as giving “our industry a licence to continue to operate for the next 60, 70, 80 years.” Occidental acquired US-based DAC company Carbon Engineering in 2023 while continuing to expand its oil and gas operations and lobby against stricter climate regulations. Given DAC’s failure to scale meaningfully, such acquisitions may be a likely exit strategy for other companies, including Climeworks.

Mitigation deterrence refers to the concern that integrating novel carbon dioxide removal methods into climate policy and industry planning may undermine or delay efforts to decarbonise. While this is difficult to demonstrate, there are certainly clear and present risksExternal link, and many actors from countries to city councilsExternal link now rely upon significant carbon removals that may never materialise as part of their net-zero plans. Separate targets for emissions reduction and carbon removalsExternal link may reduce the risk of mitigation deterrence but do not address the risk that overhyped technologies can distort priorities and lead to catastrophic policy missteps.

DAC is one approach whose hype is starting to encounter reality. Any objective assessment shows that it is not a serious, scalable climate solution, and perhaps behind closed doors Climeworks has begun to reach this same conclusion. Last year, the company began expanding its portfolio to include other carbon removal techniques such as biochar and enhanced rock weathering, most likely because DAC is not delivering results that were expected.

In the meantime, we are burning through the remnants of our global carbon budget and stumbling towards climate tipping points that may be irreversible, even if meaningful and safe carbon removal technologies eventually emerge. That we have reached this point should compel us to decarbonise with far greater urgency than we are currently mustering, because the evidence is clear: phasing out fossil fuels as rapidly and completely as possible is our only real hope of actually stemming the climate crisis.

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