A proposed global layout of carbon capture and storage in line with a 2 °C climate target

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Carbon capture, utilization, and storage (CCUS) is regarded as one pivotal technological solution for limiting global temperature increases within 2 °C compared to the preindustrial level. Without CCUS, the total abatement cost for achieving the 2 ℃ target will increase substantially. Moving towards carbon-neutral should similarly hold CCUS in a passionate embrace. However, CCUS is still at the stage of sporadic demonstration, lacking a global large-scale deployment strategy. This makes the development of CCUS far from the ambitious temperature limiting goals set a decade ago.

The first central issue that puzzles us is how countries around the world could achieve the greatest cost savings by corporately partaking in the arduous duties of the CO2 emission reductions for CCUS. An effective task sharing depends on the responsibilities (carbon emissions) and capabilities (storage capacity) of each country. It is necessary to understand the distribution of carbon sources and carbon sinks, with their potential contributions, on a global scale. However, this topic has rarely been examined directly.

To present a satisfactory proposal, we try to disassemble this difficult problem into three meta-problems for in-depth analysis: (1) Where are the large emission sources and available storage sites for achieving the necessary emission reductions? (2) What are the economically optimal solutions of source-sink matching from a global perspective? (3) How much money is demanded and whether it is acceptable for countries or not are uncertain?

To address the above concerns, my colleagues and I worked hard together for nearly three years. We go beyond the previous research by providing an operational and economically optimal CCUS deployment strategy from a global perspective. Our research provides the first instance to identify 4,220 large-scale emission clusters by integrating the point emissions of 66,273 thermal power plants and 20,491 non-power industrial plants, with the nonpoint emissions data of 139 countries. In addition, we further estimate the effective storage potential of 794 oil/gas reservoirs and deep saline aquifers across the world. We suggest that achieving CO2 mitigation duties of CCUS in line with 2 ℃ target requires the cooperation of 85 countries/regions, among which China, USA, the EU, Russia and India will be major contributors. By 2050, even considering technological progress, the total cost of CCUS to achieve the required emission reductions is ~US$5.76 trillion, equivalent to ~0.12% of the global cumulative GDP by 2050, and the average cost is approximately US$62.7 per ton of CO2. 80% of the source-sink matches are distributed within 300 kilometers, indicating high transport feasibility.

The development of CCUS should uphold the principle of achieving shared growth through discussion and collaboration. A fair and reasonable international climate governance system must be built with the help of global cooperation. Under such a proposal, some developing countries can benefit from the development of CCUS, such as Qatar and Kuwait. Furthermore, at the oil price >US$100 per barrel, 75% of countries with CO2-EOR (Enhanced Oil Recovery) will turn profitable. Therefore, it is necessary to revive oil prices and accelerate the establishment of a global carbon market to increase the initiative of countries to deploy CCUS.

At present, high investment is hindering the commercial development of CCUS, which goes diametrically against the goal of limiting the temperature increase to 2 ℃. Our results provide a straightforward instruction on the direction for future CCUS technology breakthroughs; and meanwhile explicitly clarify the cost threshold for promoting CCUS in line with the warming target, which is very informative for the implementation of carbon trading market, carbon tax, or subsidy setting.