Imagine that burning fossil fuels is the equivalent of smoking, and that the resulting climate crisis is lung cancer. In the range of available treatments, the best option is to reduce reliance on cigarettes as speedily as possible – or, in climate terms, to reduce energy consumption and speed up the transition to renewable sources.
Sometimes, however, either it is impossible for the smoker to stop, or too much damage has already been done, and medical intervention is needed. In the energy analogy, such efforts fall under the category of so-called “carbon removal”.
In the world’s race to reach net-zero emissions, “carbon removal is essentially your safety net,” says Jonny Peters from the think tank E3G. Not all sectors will be able to reduce their emissions as far or as fast as science requires; technologies that can mop up excess carbon will be necessary to uphold industries such as aviation, agriculture and concrete production. Carbon removal may also one day be used to achieve “net negative”, whereby more emissions are removed than emitted, Peters adds.
Options for carbon removal range from nature-based solutions – such as forest protection, restoring peatland and whale conservation – to speculative high-tech machines and processes. Potential technological fixes include bioenergy with carbon capture and storage, known as Beccs, which involves burning wood, vegetation or waste for power, capturing the carbon dioxide and storing it underground (as piloted by the UK power station Drax). Meanwhile, direct air capture (Dac) sucks carbon from the atmosphere before it is stored underground. The world’s biggest Dac project opened in Iceland last year.
In contrast, the potential use of carbon capture storage, or CCS, by the fossil fuel industry should not be considered carbon removal, warns the UCL professor Jim Watson. He argues that it still allows some emissions to be released and doesn’t lead to a net reduction.
To meet climate goals the world will almost certainly need carbon removal solutions, according to exploratory pathways modelled by the latest report from the Intergovernmental Panel on Climate Change (IPCC). And there is big money and big names behind these technologies. Elon Musk has set up a prize fund of $100m (£77m) for the best carbon capture technologies. Microsoft, United Airlines and ExxonMobil are all investing heavily in the field.
Yet, like lung transplants, such processes are costly and full of potential complications. To be used at scale, Beccs requires huge areas of land, which could have implications for food prices and biodiversity, while nascent Dac schemes require a lot of energy to operate. Plus, questions remain around how and where to store the sequestered carbon safely and in perpetuity.
Some experts, such as Genevieve Guenther, founder of the End Climate Silence project, argue that the inclusion of such technologies in the IPCC’s models is encouraging policymakers to treat carbon removal technology as a fait accompli and delay essential emissions reductions policies – which in turn makes a self-fulfilling prophecy out of its stated “need”.
Meanwhile, the UK government’s new energy security strategy, published yesterday (7 April), also seems similarly overly optimistic that net zero is a question of technology rather than an end to business as usual.
The strategy has been widely criticised for failing to provide support for lowering energy use (and bills) by improving efficiency, and for expanding support for domestic oil and gas. The Climate Change Committee (CCC), a government advisory body, warns that oil consumption should fall 46 to 62 per cent by 2035, and by 84 to 98 per cent by 2050. Meanwhile the consumption of unabated fossil gas should reduce by around 65 per cent by 2035 and be almost eliminated by 2050 if net zero is to be reached within the necessary timescale. The CCC’s annual progress report in June should show whether the energy security strategy is in line with the UK’s net zero target.
“The UK announcements rely on equipment like CCS, Beccs and Daccs [Direct Air Capture with Carbon Capture Storage], which can certainly be built and operated, but don’t have a long operating track record,” says Stuart Haszeldine, the world’s first professor of CCS at the University of Edinburgh.
“The government is definitely wrong to rely on the safety net,” adds Peters. “Because are simpler things we could be doing further and faster now — which avoid the need to rely on the really tricky stuff, like land use for carbon removal, where you run into issues balancing producing commercial biomass using and other essential things like biodiversity and food.”
In this context, it’s also important to emphasise that using CCS to “abate” emissions from dirty energy should, in particular, not be seen as an alternative to widespread cuts in fossil fuel use, cautions Steve Smith from Oxford University’s Oxford Net Zero initiative. “We’ve got to cut emissions as if carbon removal won’t work, and we’ve got to scale carbon removal as if we won’t cut emissions fast enough.”
Others, such as Friends of the Earth’s Mike Childs, author of a report titled “A dangerous distraction – the offsetting con”, are even starker in their concern: “When climate scientists tell us there is a need to remove carbon from the air they are not giving politicians the green light to carry on polluting. Instead, they are saying greenhouse gas levels are already dangerously high. The best way to act on carbon pollution in our atmosphere is not to put it there in the first place.”