The importance of CCS in light of the exploratory data analysis of the IPCC AR6 Energy Scenario dataset
CCS technologies refer to a range of techniques used to capture and store carbon dioxide emissions from emission sources. These technologies represent a promising means of removing carbon dioxide (CO2) from ongoing processes and extracting previously released emissions through direct air capture. CCS provides a hybrid solution that offers both direct mitigation and removal of emissions, making it a valuable tool in achieving the aims of all actors in the climate and energy multidimensional challenges. As it allows the continuation of known and mature energy demand processes in a low-carbon environment, thus it ensures alleviating the economic impacts associated with limiting global warming to below 2°C by the end of the century.
Despite its significance, the estimated operational and developmental capacity of CCS remains insufficient to achieve the projected targets of limiting global warming to below 2°C. The gap between the current technological progress and the required technology deployment scale underscores the utmost importance of enhancing investment and fostering collaboration between energy producers and consumers to scale up CCS.
Advantages of CCS
CCS has emerged as a fundamental solution that supports global decarbonisation and ensures reduced climate mitigation costs. CCS provides a development pathway that permits existing industries and industrial processes to continue functioning in a low-carbon economy. Furthermore, it allows for capturing past emissions from the atmosphere. Thus, it fits the target of all actors in energy and climate-interrelated challenges by reducing energy-related emissions.
CCS can be integrated with existing power generation plants to allow them to function in a low-carbon economy without the need to retire them. This reduces the economic impact of decarbonising the power generation sector, which is responsible for a large share of CO2 emissions. In 2021, it accounted for 36% of global CO2 emissions.
Furthermore, CCS presents a practical solution for decarbonising hard-to-abate industries, such as steel and cement, which contribute to approximately 25% and 27% of global industrial CO2 emissions, respectively (UNECE, 2022). Notably, progress is being made in industrial applications of CCS. Currently, the construction of the first CCS-equipped cement plant is underway in Norway. Similarly, in the United Kingdom, a net-zero cement plant is being built, incorporating CCS technology. For iron and steel production, there is currently only one fully operational CCS-equipped plant, located in the United Arab Emirates.
Additionally, CCS can effectively address emissions originating from the supply side. This technology plays a crucial role in reducing CO2 emissions associated with the processing of natural gas, thereby minimising the environmental impact of natural gas production. Notably, successful projects such as Sleipner and Snøhvit in Norway, along with the recently operational Qatar LNG CCS, have demonstrated the effectiveness of CCS in this aspect. At present, the predominant application of CCS technology is observed in natural gas processing, which accounts for approximately 70% of operational CCS projects globally. This amounts to around 30 MtCO2, representing the majority of CCS deployment in operation.
In addition to its role in reducing emissions from energy demand and supply sides, CCS enables the production of low-carbon hydrogen that can play a substantial role in decarbonising hard-to-abate sectors. CCS technologies offer a development pathway to the existing carbon-intensive conventional hydrogen production processes to produce blue hydrogen, which currently has substantial cost benefits over other hydrogen types. Nowadays, almost all hydrogen is produced from hydrocarbons. The most widely used hydrogen production technology is steam-methane reforming (SMR). This method accounts for around 75%, or 70 MtH2, of global hydrogen production (Massarweh et al., 2023). This mature process involves utilising high-temperature steam to produce hydrogen from a methane source, typically natural gas. The resulting specific CO2 emission of the produced hydrogen is estimated at 8.5 KgCO2/KgH2 (Katebah et al., 2022). By implementing CCS, the specific CO2 emissions of hydrogen production from SMR can be reduced by 90%. It is worth noting that applying CCS to SMR with a CO2 capture rate of 90% may result in a 35% increase in the cost of the produced hydrogen, yet is more economically competitive than hydrogen produced from electrolysis.
A key technology in limiting global temperature rise
In order to quantify the importance of CCS as a climate solution, the scenarios produced for the Working Group III of the IPCC Sixth Assessment Report are used. These scenarios describe possible realisations of global energy under different sets of energy policy and technology assumptions. Also, the scenarios were classified according to their resulting global temperature increase at the end of the century. The dataset of the scenarios was used to compare the demand of each energy source in each emission category that meets limiting global warming to 2°C or below (1.5°C, 1.5°C with overshoot, 2°C with high probability “P>67%”, and 2°C with medium probability “P>50%”) as presented in Figure 1.
Figure 1 Distribution of primary energy demand by fuel in 2050 for different global warming at the end of the century
Source: Chart made by the author based on AR6 Scenario explorer and database hosted by IIASA, Edward Byers, Volker Krey, Elmar Kriegler, Keywan Riahi, et al., 2022. Found at: data.ece.iiasa.ac.at/ar6//
Figure 1 presents the distribution of the projected primary energy demand for each energy source at different emissions categories in boxplots. These boxplots allow for a convenient comparison of scenario expectations for each energy source, where the body of each boxplot represents the projected demand range.
From Figure 1, if the 2°C target is met, fossil fuels will still make up the majority of the energy mix as indicated by the higher natural gas, and oil projected demand, followed by solar and wind. Interestingly, if the 1.5°C target is achieved, fossil fuels are still occupying a large share of the global energy mix. As a result, the continued use of fossil fuels is indispensable in almost all scenarios that aim to simulate limiting the temperature rise to below 2°C. However, the use of fossil fuels unavoidably results in CO2 emissions, highlighting the crucial requirement for the widespread deployment of carbon mitigation and removal technologies like CCS.
From the same dataset, the IPCC assessed energy scenarios dataset, a visual representation of the projected range of CCS capacities was generated for each temperature rise category in 2040 and 2050 as shown in Figure 2. The results suggest that to effectively constrain the global temperature increase to 2°C or less by the end of the century, it is estimated that the necessary global CCS capacities would be within the range of 4,000 to 12,000 MtCO2 by 2050. It is important to note that a positive correlation exists between the level of CCS technology deployment and the degree of reduction in temperature rise. As the climate target becomes more ambitious, the level of CCS deployment increases accordingly. Furthermore, in addition to the magnitude of CCS implementation, the speed at which the technology is developed also plays a significant role. This is evident as the 1.5°C category requires higher CCS deployment in 2040 and 2050 than the 2°C. In summary, in order to meet ambitious climate targets, it is imperative to accelerate and expand the deployment of CCS technology.
Figure 2 CO2 to be captured in 2040 and 2050 based on IPCC-assessed scenarios (MtCO2)
Source: Chart made by the author based on AR6 Scenario explorer and database hosted by IIASA, Edward Byers, Volker Krey, Elmar Kriegler, Keywan Riahi, et al., 2022. Found at: data.ece.iiasa.ac.at/ar6//
CCS is a climate solution for reducing emissions from both the energy demand and supply sides. The quantitative analysis of the role of the latest energy scenarios dataset produced for the IPCC Sixth Assessment Report shows the need for scaling up the technology at a fast pace to limit global warming to below 2°C.
