Stuart Haszeldine: We’re in the carbon wars. Paying to capture and store carbon is like paying for waste collection

Original article published by Energy@Ed.

The Intergovernmental Panel on Climate Change (IPCC) has long been counting on the worldwide deployment of carbon capture and storage technologies. The IPCC’s influential 2018 report presented four scenarios for limiting the temperature increase to 1.5 degrees Celsius above pre-industrial levels. Three of these scenarios assumed that between 350 and 1,200 gigatons of CO₂ would be captured and stored during this century. More recently, the IPCC noted that storing the required CO₂ quantities underground is feasible and that capturing CO₂ directly from the atmosphere will be essential to counter residual emissions from aviation, shipping, and the chemical industry. However, the deployment of carbon-negative technologies is significantly slower than that envisaged by the IPCC. In his interview for Energy@Edinburgh, Edinburgh’s renowned geologist and climate scientist Stuart Haszeldine suggests ways in which carbon capture and storage technologies could nevertheless realise their potential.

According to the Institute for Energy Economics and Financial Analysis, carbon capture and storage is “an expensive and unproven technology that distracts from global decarbonisation efforts”. However, the University of Edinburgh professor stresses that “expensive” is a relative term. “If we take the idea of decarbonising petrol, let's say petrol is sold for £1.50 per litre, about half of which is tax. If we wanted to decarbonise and capture the carbon dioxide and store the carbon dioxide from burning all of that one litre of petrol, the price would increase to £1.70. This makes it more expensive, but that's well within the normal range that petrol prices have shifted”. The director of Edinburgh Climate Change Institute likens carbon capture and storage to common services that individuals rely on in their lives. “I don't tip my rubbish in the street, which would be cheap. More expensive is to pay somebody to take it away and store it permanently. That’s an analogy for putting carbon dioxide up into the common atmosphere”. An analysis by the Energy Transitions Commission also disagrees with sceptical economists: as CCUS technologies will likely apply only to 5-15% of today’s fossil fuel demand, their deployment cannot realistically mean “business as usual” for fossil fuel emitters: the supporters of the technology largely admit that it must be accompanied by other means of mitigating emissions.

Stuart Haszeldine argues that to have a chance to contribute meaningfully, carbon storage technologies need to operate within a reformed economic environment: “The key point is not to charge for emissions but to pay for storage. It becomes a profit- making activity where people coming out of oil and gas companies can, with the same skills but perhaps a different motivation, create new companies which handle carbon dioxide in the same way that oil and gas are handled. Being penalised for emitting clearly has not worked,” says the scientist, implying that the EU’s emissions trading system, which the union gradually adopted after the 1997 Kyoto Protocol, has not truly incentivised carbon storage. “What's happened there is that companies that emit carbon dioxide are just choosing to pay slightly higher prices to carry on behaving badly. Whereas we are trying to find a fundamental way of changing the polarity to be rewarded for behaving well”. If a larger-scale deployment of CCS is achieved through similar incentives, Edinburgh researchers believe it may eventually help reduce the costs of the technology.

Not all carbon capture is the same

Some strategies for storing carbon are cheaper than others, such as those that rely on biological processes. Indeed, some climate scientists call planting a forest a technology: “The forest attracts carbon, brings carbon down from the air, and stores that in the biomass in the trees”. While the IPCC sees bioenergy with carbon capture and storage (BECCS) power plants as one of the main carbon-capturing strategies, Stuart Haszeldine explains that on geological timescales, biological storage is only temporary, lasting up to a few hundred years. For long-term storage, other solutions are necessary, whether it be direct air carbon capture (DAC) and storage or industrial carbon capture, utilisation and storage (CCUS). “In terms of geological time scale, that long term might be 10,000 years. That's the time since the last glaciation happened in the northern part of the UK. And you can do that by compressing that pure carbon dioxide, separated from other emissions, to 70 atmospheres like in a fire extinguisher, and injecting that liquid maybe 2 or 3 kilometres deep underground, where that carbon dioxide will seep into the tiny pores between the sand grains of rock”.

Other methods of carbon storage are currently being researched, lying between short- term biological and long-term geological storage. In Scotland, they often involve basalt rock and biochar. “Some sorts of rock, particularly volcanic rocks like basalt, are chemically reactive. Carbon dioxide dissolved in water can act as a chemically reactive weak acid. Test projects focus on injecting carbon dioxide dissolved in water into rock formations to understand how fast that reacts and forms solid minerals,” explains Stuart. Companies in Scotland already use crushed basalt waste from quarries to draw down carbon dioxide from the atmosphere. When basalt weathers in water, it releases ions that can interact with CO2 to form stable carbonate minerals or bicarbonate ions, some of which may be transported to the ocean, storing carbon securely. Crushed, fine-grained basalt can also be spread over agricultural fields, capturing and storing carbon dioxide through the natural weathering process. The Edinburgh Climate Change Institute also investigates biochar applications in agriculture. This product of pyrolysis, a more sustainable, low-oxygen thermal decomposition process, can be used in small pellets around a seed being planted. Combined with rock dust, biochar fertilises the soil around the seed and stores carbon for decades or even centuries, offering a prospective tool for farmers globally.

Why aren't we decarbonising fast enough?

In 2024, the World Meteorological Organization predicted an 80% chance that the global annual average temperature would exceed 1.5 degrees above pre-industrial levels in at least one of the next five years. Despite rapid advancements in research and ambitious global commitments, this temperature was already exceeded last year. While the UK has closed its last coal power station and is among the European countries with the fastest pace of decarbonisation, similar progress remains relatively rare in the global context: “Fossil fuels worldwide still comprise about 80% of energy. And that's energy for transport, heating, making chemicals, making buildings work, and growing food. Fossil fuels are endemic throughout our whole culture. So, it's not surprising that it's difficult to move. Politicians have taken a quite superficial view of this and have taken the path of minimum resistance in some ways by declaring targets and ambitions and claiming that they are based on science, which often the numbers are. But there's a huge gap between those claims, wishes, and ideas and the actual practical reality of delivering decreases in CO2 emissions”. Having recorded the lowest emissions since 1879, statistics for the UK suggest that the country could serve as a potential model for decarbonisation for other countries. However, when emissions are measured per capita—dividing total emissions by the populations of states — Great Britain does not perform as well: “It's also true that if you do the accountancy quite rigorously, then some of those emissions, instead of being emitted onshore in Europe, have now gone away to be emitted onshore in Africa or onshore in parts of China to where the manufacturing has been relocated”. Nevertheless, Stuart Haszeldine emphasises that both the United Kingdom and the European Union have acted on their climate goals and that the overall trend is one of evident improvement.

If reducing greenhouse gas emissions remains a clear goal, the know-how associated with past carbon-heavy processes can be an asset in decarbonisation: “There's a famous saying that the oil industry isn't going to run out because we're out of oil, in the same way that the Stone Age didn't run out of stone to move on to the next era. People use their technologies and knowledge to move forward into the next space”. Edinburgh’s local neighbourhood exemplifies this dynamic, having been the birthplace of the shale oil industry. “The chemical industry's refining expertise then acted to locate the present-day oil refineries and petrochemical works there. Now, they are moving away from refining crude oil and gas out of the North Sea into making more complex petrochemicals and possibly starting to use biomaterials as a biomass feed.” Sites previously used for extracting carbon-based resources can be repurposed as carbon storage locations. Pipelines similar to oil and gas pipelines can transport carbon and hydrogen, a likely future energy resource that requires storing and transporting. Strikingly, even carbon capture and storage itself was developed within carbon-heavy industries to increase oil production by injecting CO2 into oil wells, a goal almost opposite to carbon-negative technologies’ current role.

The role of universities

Without scientific insights from geophysics, engineering, politics, and economics, technologies like carbon capture and storage risk becoming less viable than they could be. “We're in the carbon wars. So, if we're fighting against too much carbon, we want to be in there doing the technical, scientific stuff to make it smarter.” The university’s diverse scientific community aims to promote teamwork and cooperation that enhance individual scientific contributions: “One of the great things about Edinburgh University is its huge diversity of people from different corners of the world, but also diversity in the skills, techniques, and knowledge which people can bring. If you've got a problem and you're in a meeting room in the middle of Edinburgh, within three phone calls, you might find an international expert who can help you.”

Professor Stuart Haszeldine is a Co-Director of the Edinburgh Climate Change Institute and the Director of Scottish Carbon Capture and Storage, the UK's largest CCS research group. Over the past 35 years, Stuart has conducted research in energy and environmental science, developing innovative approaches to oil and gas extraction, radioactive waste disposal, carbon capture and storage, and biochar application in soils. He provides advice to both the UK and Scottish governments and frequently appears as a scientific expert on media programmes discussing climate issues. Stuart is a recipient of the Geological Society's William Smith Medal and holds an OBE for his contributions to climate change technologies.

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