On 5th November 1605 a conspiracy of English Roman Catholics, angered by King James I’s refusal to grant them more religious tolerance, resulted in the Gunpowder Plot. This secret plan was to blow up the Palace of Westminster, otherwise known as the Houses of Parliament, the supreme legislative body of the UK. The conspirators, who included Guy Fawkes, rented a cellar beneath the building where they planted barrels containing one ton of gunpowder. But their plot was uncovered, with Fawkes arrested, tortured and executed. This episode in UK history demonstrated the drastic measures felt to be warranted by certain factions within society if they deemed certain elements of legislation to be deficient. Today, many UK residents consider current legislative deficiencies to include those dealing with carbon capture and storage. In light of this, there is likely to be a mandatory requirement for appropriate legislative measures to be implemented for industrial plants where large volumes of carbon dioxide are produced and emitted. Of the 118 chemical substances listed in the periodic table of the elements carbon is, by mass, the 2nd most abundant element in the human body and the 4th most abundant element in the whole of the known universe. Hence its importance to life and living organisms cannot be overstated. However, in certain ways carbon is injurious to human health. Indeed, under the 2002 Control of Substances Hazardous to Health Regulations, carbon dioxide is classed as a substance hazardous to health.
Carbon dioxide gas is emitted when fossil fuels are burned to meet domestic and industrial demands for energy and whilst it is not the only greenhouse gas, carbon dioxide is the most significant. Furthermore, from a scientific and environmental viewpoint the evidence is clear that the emission of greenhouse gases, resulting from human activity, is causing climate-change. Therefore, to address this matter, in June 2019 the UK became the first major economy to pass legislation committing to ‘net zero’ emissions by 2050 thereby setting a target to reduce net greenhouse gas emissions by 100%, relative to 1990 levels, by the middle of the 21st Century. ‘Net zero’ refers to the balance between the carbon emitted into the atmosphere and the carbon removed from it, and in order to achieve net zero the emissions from homes, transport, agriculture and industry will need to be reduced. Current data indicates that the percentage average carbon dioxide emissions by mass are: heating 30%; transport 25%; electricity 9%; aviation 12%; food & farming 20%; and waste disposal & treatment 4%. However, notwithstanding the net zero target, some sectors, such as aviation, will be too complex or prohibitively expensive to cut emissions altogether. Any ‘residual’ emissions will therefore need to be removed from the atmosphere either by changing land-use to enable it to absorb more carbon dioxide, or by way of developing new extraction technologies in carbon capture, usage and storage.
Carbon dioxide gas is non-flammable and heavier than air, and it is also colourless and odourless at room temperature and atmospheric pressure. Consequently, it cannot normally be seen or smelt and whilst it is naturally present in breathable air it is not harmful to health at low concentrations. However, at higher concentrations the gas may become hazardous giving rise to symptoms of dizziness, headaches, confusion and loss of consciousness. Moreover, as this gas is heavier than air it may sink thereby displacing oxygen, and if it is kept in confined spaces its concentration may further increase substantially giving rise to the risk of death from asphyxiation.
In the environment, an air concentration of 350 parts-per-million carbon dioxide is thought to be the longstanding norm (established from analysing ice from the polar ice-caps and fossilised leaves), standing until the 1960s when the world started to industrialise in earnest. Levels are now hovering around 410ppm and increasing rapidly. Around levels of 1,000ppm humans feel drowsy, with increasing nausea and difficulty concentrating. Levels of carbon dioxide exceeding 5,000ppm shall suffocate. Evidence from arctic ice samples, fossils and sedimentary rocks lend credence to the theory that volcanic activity caused Pangea, a supercontinent that existed in the Paleozoic/Mesozoic geological Periods, to split up during the late Triassic Period resulting in carbon dioxide concentrations rapidly increasing to 6,000ppm which led to the extinction of the dinosaurs. Carbon dioxide concentrations today may be nowhere near that point but concentrations are indeed increasing rapidly.
Whilst for these reasons alone carbon emissions should be addressed, emissions must also be addressed for the wider UK economy to achieve sustainable status. Existing and future legislation suggests there will be inevitable mandatory reductions in carbon dioxide emissions relating to climate change, and in order to secure positive environmental and social impacts that will support the protection of wildlife, the promotion of biodiversity, and the improvement of a community’s livelihood. But the world’s energy demand is forecast to increase by approximately 50% by 2030, meaning that fossil fuels are likely to remain an important contributor to the energy mix for many years to come. Consequently, carbon capture, utilisation and storage technologies will be of fundamental importance in the fight to compensate for individual and collective carbon footprints, but the methods and means of harnessing these technologies remain uncertain.
The Russian born Belgian Chemist Ilya Prigogine, who was Professor of Physics and Chemical Engineering at the University of Texas and winner of the 1977 Nobel Prize in Chemistry, once stated:
‘The future is uncertain, but this uncertainty is at the very heart of human creativity.’
This prompts a reference to a quotation from the late John Lennon who stated:
‘Creativity is a gift. It doesn’t come through if the air is cluttered.’
‘Certainty’ and ‘creativity’ in the effectiveness of carbon capture, utilisation and storage technologies are paramount in meeting the environmental, health and political challenges we face. An ongoing environmental challenge warranting attention is greenhouse gas emissions and, nearly 50 years ago in 1977, the concept of reducing such emissions by the use of carbon capture and storage was first proposed by Cesare Marchetti the Italian physicist whose areas of research included the hydrogen economy and geo-engineering. Eleven years later in 1988 ongoing concerns regarding emissions contributed to the creation of The Intergovernmental Panel on Climate Change. This was established to provide policymakers with regular scientific assessments on climate change, to appraise associated future risks, and to promote mitigating measures. To assist in these endeavours the Panel chose to define carbon capture and storage as: ‘A process in which a relatively pure stream of carbon dioxide from industrial and energy related sources is separated, captured, conditioned, compressed and transported to a storage location for long-term isolation from the atmosphere.’
In 1996 a Norwegian gas field became the very first site of a large-scale carbon dioxide capture and storage project that was commissioned to combine gas injection, dedicated storage, and monitoring facilities. This heralded the beginning of the global carbon capture, utilisation and storage industry which then grew into a burgeoning sector comprising 150 fully operational global projects charged with managing 130 million tonnes of carbon dioxide annually by the year 2020. However, 7 in 10 of these projects were not implemented due to a variety of hindrances that included: high operating costs; a lack of social acceptability; threats to funding; external budgetary pressures; and a lack of means to address the long-term liability of carbon dioxide storage. All of these shortcomings contributed to project cancellations.
Subsequent work by various carbon capture & storage (CCS) projects around the world have successfully proven the technology and laid bare some of the challenges. The financial cost is the biggest immediate challenge to CCS. The lion’s share of the cost of CCS is sunk in the ‘Capture’ side of the process. ‘Low-emission’ sources of carbon from the traditional smoke-stack industries (coal-fired and gas-fired power plants, steelworks, cement factories, bulk chemicals etc) require carbon dioxide produced from the relevant industrial process to be separated from the flue emissions at the factory. This typically takes place in a carbon capture reactor (‘carbon dioxide scrubber’), where a solid or liquid adsorbent or absorbent is employed to capture the unwanted gas. Such a process has been used since the 1950s, introduced to keep the air fresh and breathable inside submarines. After scrubbing, the carbon dioxide gas can be released via heating or pressure changes in a more concentrated form that can be pressurised and then stored relatively cheaply in suitable geological formations.
The support of CCS by the UK government is considered as a knee jerk reaction to the potential fallout from a failure to achieve net zero. Whilst CCS does, if successful, provide some relief to carbon emissions, it is little more than a transitional technology to ‘greenwash’ those industries for which carbon pollution abatement is difficult. Furthermore, little legislative foresight has been given to: the management of the long-term liability and sustainability of under-ground storage; the local environmental consequences of noise pollution; risks from seismic activity; and health risks to the local population. In October 2024 the UK government announced “Government confirms funding to launch the UK’s first carbon capture sites, set to bring thousands of new skilled jobs, billions in private investment and support acceleration to net zero.” Furthermore, in July 2025 another announcement guaranteed 3500 jobs and savings for the public in the north west of England. However, whilst the promised benefits are yet to be seen the impact on local communities through dirty manufacture is already evident with local carbon producers regularly failing to meet targets. CCS is a short-term gamble to meet net zero pitted against a long-term problem which may be difficult to resolve. Investment into alternative carbon recycling through natural means i.e. bioreactors, waste reduction and cleaner energy production will provide results without incurring high-cost low-yield penalties through CCS.
A great deal of CCS projects take place in the United States and Canada, owing to the space available and suitable geology. Alarmingly, the University of Utah has estimated that a 50%-80% increase in the cost of electricity is required to pay for the implementation of CCS in coal and gas power stations, that being without a government subsidy. The US is happily riding a shale gas boom and has abundant cheap energy, so it might not hamper the international competitiveness of American industry. Britain, in contrast, has the highest energy costs in the G7 already. Heaping further costs on carbon-intensive industrial producers who are already struggling to compete with their international peers would be economically disastrous. As things stand, almost two thirds of British manufacturers cite energy costs as their main reason for not expanding, according to a survey run by the auditor Ernst & Young.
For a moment let us reflect on the profound views of two very different historical figures. In the 18th Century, thoughts from Napoleon Bonaparte, French General and European Statesman comprised:
‘Water, air and cleanness are the chief articles in my pharmacy’
Whilst a hundred and fifty years later the words of Franklin D. Roosevelt, the 32nd President of the United States confirmed:
‘A nation that destroys its soils destroys itself. Forests are the lungs of our land, purifying the air and giving fresh strength to our people’
Currently approximately 80% of captured carbon dioxide is employed in the enhanced recovery of oil. The benefits of this are two-fold, aiding extraction of oil and providing a repository for carbon dioxide. The process of aiding oil extraction entails the injection of the gas into existing oil field reservoirs which are partially depleted (as most of the North Sea fields are). This has two distinct effects. Firstly, it increases the oil pressure within the reservoir and so improves the overall mobility of the oil, and secondly, the injected gas combines with any remaining oil thereby reducing the latter’s density, increasing its effective buoyancy, and improving its rate of upward flow toward the production wells. However, once the total recoverable reserves of oil have been extracted the deep underground geological reservoirs that remain are often used as storage vessels for captured carbon dioxide gas. But before the gas is injected into such reservoirs formed in rock it is compressed into a supercritical fluid which has properties between those of a gas and a liquid.
Above its critical temperature and critical pressure carbon dioxide behaves as a supercritical fluid, expanding like a gas into any confined space like a gas but with a density similar to that of a liquid. Moreover, whilst it behaves as a gas in air at standard temperature and pressure, carbon dioxide behaves as a solid known as dry ice whenever it is cooled and/or pressurised to a sufficient degree. To retain carbon dioxide in a fluid state within a subterranean reservoir the latter must be located at a depth of at least 2,500ft but if the injection of carbon dioxide creates underground pressures that are excessive this may create fractures within rock formations. Technically such ‘over-pressurised’ conditions could even initiate geological effects in the form of seismic activity. Moreover, ‘caprock’, comprising a stratum of hard impervious rock that is employed to overlay and seal an oil or gas deposit, must be able to withstand the chemical and physical property changes caused by mechanical and chemical interactions of any pressurised carbon dioxide, water and various minerals embedded within the rock formation. However, any changes in the forces applied to such a storage system after the injection of carbon dioxide gas will gradually subject the caprock to tensile, shearing and compressive forces. These forces risk the formation of fractures or faults followed by the sudden and possibly violent high-pressure leakage of carbon dioxide gas.
The Intergovernmental Panel on Climate Change has suggested that well-managed storage facilities would be capable, with a 66% to 90% probability, of being able retain over 99% of injected carbon dioxide for more than a thousand years. However, a cautionary note relates to any artificially initiated earthquake activity subsequently compromising the risk of geological fractures. Any fracture would in turn compromise the efficacy of underground storage and if very large volumes of carbon dioxide are sequestered, even a 1% leakage rate over 1000 years could give rise to profound effects of excessive greenhouse gas emissions with severe health and climatic impacts affecting future generations.
Given the above risks, weaknesses in geological capture and storage of carbon dioxide gas must be addressed. Indeed, in 2020 successive weaknesses in operating practices adopted for carbon dioxide capture and storage led the International Energy Agency to state: ‘The story of carbon capture, utilisation and storage has largely been one of unmet expectations: its potential to mitigate climate change has been recognised for decades, but deployment has been slow and so has had only a limited impact on global carbon dioxide emissions.’ So why rely on a geological solution whilst over 70% of the Earth’s surface is covered by oceans and can offer an alternative means of capturing carbon? Seawater is able to absorb in the order of 150 times more carbon dioxide than air and globally our oceans absorb approximately one quarter of all carbon dioxide emissions. This means that if new technologies can be developed to extract and store the carbon captured within seawater then low-carbon seawater could be released back into the seas and oceans to restart the carbon dioxide absorption process once more. Interestingly, marine organisms rely on carbon throughout their life-cycle with mussels using it to create their shells whilst phytoplankton, comprising microscopic plant-like organisms, employ it during the photosynthesis process to biochemically convert light energy into chemical energy. An example of natural carbon capture comprises the process by which water and carbon dioxide react in the presence of sunlight to chemically combine and create glucose and oxygen:
Water + Carbon Dioxide + Solar Radiation = Glucose + Oxygen
6H2O + 6CO2 + Solar Radiation = C6H12O6 + 6O2
Hence natural environmental processes are able to capture carbon and convert it into breathable oxygen and blood sugar which, together with protein and fat, is one of the human body’s primary fuel sources.
All businesses crave stability and certainty and in discussing the future of carbon capture the current prevailing degree of uncertainty as to its future is perhaps most appropriately illustrated by use of the phrase ‘up in the air’. In terms of certainty, it is also apt to reflect on the work of Leonhard Euler the Swiss physicist, logician, engineer and greatest mathematician of the 18th century who once stated:
‘Logic is the foundation of the certainty of all the knowledge we acquire.’
Logical efforts of many businesses, coupled with considerable expenditure over a period of 30 years, have however culminated in the capture of only one-thousandth of all global greenhouse gas emissions. In comparison, Ronald Reagan, the 40th President of the United States serving two terms from 1981 to 1989 once stated: ‘All the waste in a year from a nuclear power plant can be stored under a desk.’ Consequently, the proverbial saying ‘prevention is better than cure’ neatly lends itself to our own catchphrase solution to carbon capture: ‘go emission-free, go nuclear’. But for now, the World’s current unsatisfactory situation with regard to carbon capture and storage warrants our concluding remarks:
‘Abject Failure.’
Copyright & permissions
