Carbon dioxide removal is not a current climate solution — we need to change the narrative

Carbon dioxide removal (CDR) is what puts the ‘net’ into ‘net zero emissions’. All pathways to limit global warming to 1.5–2 °C above pre-industrial levels that have been assessed by the Intergovernmental Panel on Climate Change require rapid decarbonization to start now. But they also require the removal of CO₂ from the atmosphere because we won’t be able to eliminate carbon emissions entirely on the required time scales. ‘Hard to abate’ sectors such as aviation and shipping will remain large sources of greenhouse gases even in the most optimistic scenarios. Residual emissions will mean that we cannot achieve a zero-emissions goal, and we will need CDR to reach a net-zero target. Historically, this has meant planting or maintaining trees, but removing CO₂ from the atmosphere and storing it in the ground, the ocean or in products will be more durable.

However, businesses are springing up that promise various CDR techniques as climate solutions for today. Others are enthusiastically buying carbon credits — essentially, investments in planting trees, or other future CDR capacity — as part of their current decarbonization commitments.

I have spent my career studying the natural carbon cycle and, in recent years, developing methods for checking that CDR works. I have scrutinized dozens of proposals, and I was a reviewer for the US$100-million XPRIZE Carbon Removal competition funded by the Musk Foundation. I don’t deny the need to develop CDR methods over the longer term. And I welcome governments committing much-needed resources to this area. After some small-scale demonstrations of ‘direct air capture’ (DAC) technology, which suck CO₂ out of the atmosphere by chemical means, the 2022 US Bipartisan Infrastructure Law has devoted $3.5 billion to developing four DAC hubs. But it’s clear to me that deploying them to remove CO₂ from the atmosphere is pointless until society has almost completely eliminated its polluting activities.