Climate change, driven primarily by the excessive emission of greenhouse gases, poses a significant threat to our planet’s ecosystems and human well-being. To mitigate this crisis, it is imperative to reduce greenhouse gas emissions and explore innovative solutions. One such solution gaining prominence is carbon capture and storage (CCS).

In this first of three blogs, we look at CCS, with a spotlight on offshore CCS, and why it has an important role to play in combatting climate change.

Unfortunately, capturing carbon dioxide (CO2) from many smaller scale emitters – such as homes, cars and aircraft – is difficult and financially impractical. Therefore, CCS involves the at-source capture of CO2 from large scale emitters, such as power generation plants, manufacturing and other industrial processes, and storing it securely in geological structures deep underground.

This technique offers a promising approach to reducing emissions while allowing for continued economic activity.

Generated image of industrial chimneys emitting smoke

Global progress and statistics

Global energy-related CO2 emissions grew by 0.9%, or 321 million tonnes, in 2022 reaching a new high of more than 36.8 billion tonnes per annum. Figures show that as of 2023 there were over 700 onshore and offshore CCS projects in various stages of development across the globe with the potential for capturing and storing 244 million tonnes per annum (Mtpa) of CO2. The Global CCS Institute reports that while the total capacity of CCS projects in development has increased significantly it’s still a fraction of what’s needed to meet global climate goals. The projected on and offshore CCS capacity by 2030 is 435 Mtpa of CO2, which is still short of the 1 gigaton per annum (Gtpa) needed to meet net-zero emissions targets by 2050.

Governments worldwide are recognising the importance of CCS in achieving these climate goal objectives and are implementing policies to support their development. Notable government initiatives include:

• The UK government has outlined plans to create a competitive market for CCS by 2035, aiming to capture and store 20-30 million tonnes of CO2 per year by 2030.
• The EU has set a target of capturing and storing at least 50 million tonnes of CO2 annually by 2030.
• The United States has allocated significant funding for CCS projects through the Infrastructure Investment and Jobs Act and is a world leader in CCS deployment.

Offshore Carbon Storage: A Promising Solution

Once captured, the CO2 is stored in deep underground structures such as depleted oil and gas reservoirs or saline aquifers. These CCS sites can be either land-based or offshore with land-based being (to date) the largest dedicated CCS growth area.

Nonetheless, offshore CCS offers several advantages: the key one being the availability of existing oil and gas infrastructure for both CO2 transportation and storage. As well as reducing installation costs, the use of pre-existing pipelines helps to allay public concerns and objections around safety or further disruption to the environment.

Additionally, many large-scale emitters are situated near to the coastline, meaning that any new transportation pipelines may be able to bypass populated areas, thus avoiding additional construction costs and decreasing the likelihood of public objections.

However, several key considerations for offshore carbon storage remain, such as:

• Environmental impact: Monitoring and assessment of potential risks to marine ecosystems are crucial.
• Geological suitability: Ensuring the long-term security of the stored CO2 requires careful selection of storage sites.
• Regulatory framework: The development of clear and robust regulations is essential for governing offshore carbon storage activities and instilling public confidence in the process.

Diagram illustrating carbon capture storage. (Global CCS Institute)

Offshore CCS: Key challenges

Safety and the avoidance of creating a new environmental issue whilst mitigating another are a key challenge to the large-scale adoption of offshore CCS. Rigorous geological and environmental assessments are crucial to ensure safe long-term CCS containment and to prevent any adverse marine impacts.

Research has shown that even small carbon dioxide releases (in the order of < 1 tonne per day) can have a temporary impact on subsea environments, while greater releases have the potential to be catastrophic with a permanent effect on marine habitats.

Despite its potential, the widespread adoption of CCS faces several challenges, including high costs, technological limitations and public concerns about the long-term safety of geological CO2 storage.

• Cost reduction: Technological advancements and economies of scale are essential for making CCS more cost-effective.
• Public acceptance: Building public trust and addressing concerns about the safety of CO2 storage is crucial for the successful deployment of CCS.
• International cooperation: Collaborative efforts between governments, industries, and research institutions are essential for advancing CCS technology and addressing global challenges.

Thankfully, ongoing research and development are addressing these issues and driving down costs.

Carbon capture and storage is a vital tool in the fight against climate change. By capturing and storing CO2 emissions, CCS can reduce greenhouse gas concentrations in the atmosphere and, therefore, help to mitigate the impacts of climate change. While there are some challenges to overcome, the potential benefits of CCS make it a promising opportunity for actively addressing the climate crisis.

In our next blog, we will be discussing the importance of reliably monitoring offshore CCS sites and looking at how our technology can help to advance this.

Stephen Auld.

Blog 2 – The critical role of monitoring in subsea carbon capture and storage

Blog 3 – Revolutionising carbon capture and storage monitoring Sonardyne’s cutting-edge approach