The idea that all the problematic carbon dioxide emissions in the future can be safely and permanently buried in the ground with carbon capture and sequestration (CCS) technologies might be extremely misplaced and impractical, a new study by researchers of Oxford University and Imperial College in London suggests. It might be technically possible, and in some cases, desirable, but heavy reliance on CCS to achieve net-zero levels might not be viable, the study said. CCS involves the capture of carbon from the source of emissions, like a power plant or a cement factory, and storing it below the ground in suitable geological structures such as depleted oil or gas reservoirs or some specific rock formations to prevent the release of these carbon emissions into the atmosphere. All net-zero emissions pathways to 2050 put forward by the Intergovernmental Panel on Climate Change involve some deployment of CCS technologies. There are currently no projections which make the world net-zero without some sort of carbon capture and sequestration. Emission pathways that require the world to put up to 20 billion tonnes of carbon dioxide underground in 2050 to achieve net-zero could cost at least US$ 30 trillion more than the pathways in which only about 5 billion tonnes have to be stored. “This can be prohibitive. As mentioned in the study, these are expected to be the lower end of the estimates. The actual cost differential between the high-CCS and low-CCS scenarios could be much higher. And this makes it extremely unattractive and damaging economically, if not totally impossible,” Richard Black, one of the authors of the study and a research fellow at the Grantham Institute, Imperial College, said in an interview with The Indian Express. “A blanket use of CCS technologies, as a solution to rising emissions, must not be relied upon. Frankly, that is not even an option, I think,” Black said. Significantly, the study found there had been no cost reductions in any part of the CCS process as the technology progressed in the last 40 years. “It’s not very surprising. Not all technologies undergo rapid cost reductions. The cost of nuclear power, for example, is now rising, if anything. The cost of hydropower is rising slightly. The ones where you see rapid cost reductions are the ones you can produce in volume, which does not apply to CCS technologies. So, even if the CCS technologies are scaled up from the current installations, it is unlikely to bring down the costs. At least that is what we have found with past trends,” Black said. As of now, all CCS projects around the world have a combined capacity to put away about 49 million tonnes of carbon dioxide emissions. That is just about one-thousandth of the annual CO2 emissions. “The fact that governments are not rapidly scaling up CCS technologies means even they realise it is not a very feasible option. It is useful in certain situations, like when it is applied to sectors like cement or iron and steel. There are few or virtually no options to reduce emissions from these industries. It makes sense to use CCS to capture carbon at source and deposit it below the ground. But there are much better options available in other sectors. Replacement of fossil fuels with renewables, afforestation are much cheaper and more effective ways of dealing with emissions,” he said. “There have also been at least two instances where the projects just did not work as designed,” Black said. “CCS needs to be deployed in a strategic and targeted manner. This idea that because we have CCS, we can continue using fossil fuels for a longer time won’t work. We need to do sensible things like shifting to renewables and halting deforestation.”
