Carbon sequestration

What Is Carbon Sequestration?

Carbon sequestration is the long-term removal, capture, and storage of carbon dioxide ((CO_2)) from the atmosphere or from industrial emission sources. This process is a critical strategy within the broader field of Environmental Finance and Climate Change mitigation. The primary goal of carbon sequestration is to reduce the concentration of Greenhouse Gas Emissions in the atmosphere, thereby combating global warming. Methods of carbon sequestration involve both natural processes, such as absorption by oceans and forests, and engineered solutions, like capturing emissions from power plants and industrial facilities for underground storage. Projects involving carbon sequestration are often evaluated for their impact on a company's Carbon Footprint and their alignment with Sustainability objectives.

History and Origin

The foundational concept of carbon capture and storage (CCS) emerged in the mid-20th century, primarily within the oil and gas industry. Initially, carbon dioxide was injected into oil fields to boost reservoir pressure and facilitate the extraction of more crude oil, a process known as Enhanced Oil Recovery (EOR).³³, ³⁴, ³⁵ While (CO_2) capture technology itself has been used since the 1920s, the idea of capturing (CO_2) to prevent its release into the atmosphere was suggested in 1977.³² As global awareness of climate change intensified, the application of carbon sequestration evolved beyond EOR to become a dedicated strategy for mitigating atmospheric carbon emissions. Early development faced obstacles such as high costs and significant energy requirements, yet pioneering commercial projects demonstrated the viability of geological (CO_2) storage.³¹

Key Takeaways

• Carbon sequestration is a process designed to capture and store carbon dioxide, preventing its release into the atmosphere.
• It plays a crucial role in efforts to achieve Net-Zero Emissions and limit global temperature increases.
• Technological applications include capturing emissions from large industrial sources and direct air capture.
• Significant challenges persist, including high implementation costs, substantial energy demands, and the need for robust regulatory frameworks.
• The effectiveness and Economic Viability of carbon sequestration projects continue to be areas of active research and development.

Interpreting the Carbon Sequestration

Interpreting the impact and effectiveness of carbon sequestration involves assessing the volume of carbon dioxide removed or prevented from entering the atmosphere, typically measured in metric tons or gigatonnes. This measurement helps determine a project's contribution to climate goals. For example, the Global Carbon Budget, an annual report, provides critical insights into global carbon emissions and sinks, highlighting the scale of the challenge. In 2023, total global (CO_2) emissions were projected to be 40.9 billion tonnes, with about half typically absorbed by natural land and ocean "sinks."²⁹, ³⁰ Effective carbon sequestration aims to augment these natural processes or capture emissions before they are released, directly impacting atmospheric Carbon Dioxide concentrations. Evaluating carbon sequestration projects also considers their long-term storage stability and the overall energy balance of the capture process.

Hypothetical Example

Consider a large cement manufacturing plant that emits significant amounts of carbon dioxide as a byproduct of its production process. To reduce its environmental impact, the company decides to implement a carbon sequestration system. The system works by installing specialized equipment that captures (CO_2) directly from the plant's exhaust gases. This captured carbon dioxide is then compressed and transported via a pipeline to a suitable Geological Storage site, such as a deep saline aquifer located several kilometers underground. The aquifer's porous rock formations can safely store the (CO_2) permanently, preventing it from contributing to Global Warming. The company can then potentially benefit from Carbon Credits based on the verified volume of (CO_2) sequestered, helping to offset the operational costs of the system.

Practical Applications

Carbon sequestration is applied across various sectors, particularly in industries with high Fossil Fuels consumption or process emissions.

• Industrial Emissions Reduction: Cement, steel, chemical production, and power generation are "hard-to-abate" industries that rely heavily on fossil fuels. Carbon sequestration allows these facilities to reduce their emissions significantly without complete structural overhauls. For instance, the world's first plant to capture (CO_2) emissions from cement production began operations in China in 2024.²⁷, ²⁸
• Direct Air Capture (DAC): This technology specifically captures carbon dioxide already present in the atmosphere, offering a way to actively remove legacy emissions.²⁶ Captured (CO_2) is then sequestered underground.
• Enhanced Oil Recovery (EOR): While the initial purpose of injecting (CO_2) was to increase oil extraction, a portion of the injected (CO_2) remains permanently stored in the depleted oil reservoir, contributing to sequestration.²⁵
• Natural Carbon Sinks: Reforestation, afforestation, and sustainable land management practices enhance the natural capacity of forests and soils to absorb and store carbon.
• Policy and Market Mechanisms: Regulatory frameworks like Cap-and-Trade systems are designed to incentivize industries to adopt carbon sequestration technologies by assigning a cost to carbon emissions.²⁴

As of early 2025, over 50 million tonnes of (CO_2) capture and storage capacity were operational globally, with significant growth projected by 2030, driven by new projects in regions like China and the Middle East.²², ²³ The Global Carbon Budget for 2023 estimated that about half of all (CO_2) emitted continues to be absorbed by land and ocean "sinks," with the remainder accumulating in the atmosphere.²¹

Limitations and Criticisms

Despite its potential, carbon sequestration faces notable limitations and criticisms. A primary concern is the substantial cost associated with developing, building, and operating these facilities.¹⁷, ¹⁸, ¹⁹, ²⁰ This financial burden can make industries less competitive, raising questions about whether funds could be more effectively allocated to other Renewable Energy or climate mitigation strategies.¹⁶

Furthermore, the energy intensity of carbon capture processes is a significant hurdle. Many methods require substantial energy, which can potentially offset the climate benefits if the energy source is fossil fuel-based.¹², ¹³, ¹⁴, ¹⁵ Scalability remains a challenge, as transitioning from pilot projects to industrial-scale operations presents considerable technical and logistical difficulties.¹¹

Critics also highlight concerns about the long-term effectiveness and permanence of underground storage, with some historical projects raising questions about seal integrity and potential leakage.⁹, ¹⁰ Public perception and the absence of clear regulatory frameworks also create uncertainties and delays in project development.⁶, ⁷, ⁸ Some argue that carbon sequestration might prolong reliance on fossil fuels by offering a perceived "solution" for continued emissions, rather than accelerating the transition to truly clean energy sources.⁴, ⁵ Many carbon capture projects have historically failed or underperformed against their designed capacities.³

Carbon Sequestration vs. Carbon Capture and Utilization (CCU)

While closely related and often discussed together, carbon sequestration and carbon capture and utilization (CCU) have distinct end goals.

The main distinction lies in how the captured carbon dioxide is ultimately managed. Carbon sequestration focuses purely on storage to prevent its return to the atmosphere, while Carbon Capture and Utilization seeks to derive economic value by integrating the (CO_2) into new products. Both approaches aim to reduce atmospheric carbon levels but employ different strategies for the fate of the captured gas.²

FAQs

What are the main types of carbon sequestration?

Carbon sequestration can broadly be categorized into geological sequestration (injecting (CO_2) into underground rock formations), oceanic sequestration (dissolving (CO_2) into deep ocean waters, though this is less common due to environmental concerns), and biological sequestration (enhancing natural carbon sinks like forests and soils). Technologies like Direct Air Capture and post-combustion capture at industrial sites are part of the broader effort.

Is carbon sequestration a proven technology?

The individual components of carbon sequestration, such as (CO_2) capture from industrial sources and its injection into geological formations, have been used for decades in various industries, notably in Enhanced Oil Recovery (EOR).¹ However, large-scale, dedicated carbon sequestration solely for climate mitigation is a more recent development, and its widespread deployment still faces challenges related to cost, energy consumption, and long-term storage verification.

How does carbon sequestration impact the economy?

Carbon sequestration can impact the economy by requiring significant upfront Capital Investment for infrastructure and operations. It can create new industries and jobs in areas like engineering, construction, and monitoring. Policies like Carbon Credits or a Carbon Tax can provide financial incentives for companies to invest in carbon sequestration, potentially leading to new revenue streams or avoiding penalties for emissions. However, the high costs remain a barrier to broader adoption without strong economic incentives.