What are the risks of Carbon Capture and Storage

Humans have been burying their garbage in their backyards for centuries. CCS is essentially a modern form of this practice. The process involves capturing CO₂ at the source and transporting it via pipeline or truck to an underground storage site, such as in geological formations deep beneath the earth's surface.

The idea is that by trapping and sequestering carbon dioxide underground, we can significantly reduce our atmospheric emissions and limit the amount of heat trapped in the atmosphere. Theoretically, this would slow global warming and its associated effects, such as rising sea levels. Scientists have found pockets of CO₂ buried deep beneath porous rock surfaces dating back millions of years.

In essence, the process goes like this:

Capture

In the US, manufacturing is responsible for about a quarter of all energy-related CO₂ emissions. The CO₂ is collected at its source — typically a power plant or industrial facility. The CO₂ is either captured in open-air or in enclosed vessels. It can also be captured at various stages of the production process.

Post-combustion capture is the most common approach. Once fuel is burned, the emissions pass through a device that extracts CO₂ from the stream. Pre-combustion capture is also used and involves capturing CO₂ directly from the fuel before it is burned. And oxyfuel combustion, the third approach, involves burning fuel in an atmosphere enriched with pure oxygen. It creates a stream of exhaust that is predominantly composed of CO₂.

Transport

Once the CO₂ has been captured, it must be transported to its underground storage site. That could be done via pipeline or truck. The transportation process would need to be carefully monitored for safety and efficiency. Ships could also be used for longer distances.

Storage

The CO₂ can then be injected deep underground in geological formations, such as saline aquifers or depleted oil and gas fields. The idea is to convert the CO₂ into a liquid, making it easier to contain and store. A variety of technologies can be used for this process. Oceans were also considered potential storage sites, which was later rejected due to already over-taxed ecosystems. Acidification of ocean water could also occur due to increased CO₂ levels.

Despite the potential benefits of CCS, it is not without its risks. Injecting large amounts of captured carbon dioxide into underground formations could lead to unforeseen consequences and long-term damage.

Potential leaks in the ground

The most immediate and obvious risk is leakage. If the CO₂ is not stored properly or fails to remain in a liquid state, it could escape and seep into surrounding areas. The leaks could lead to environmental and safety issues, including soil contamination and waterway pollution. The gas could even migrate to populated areas and cause health problems for those living nearby. In the event of a significant leak, it would add to the existing CO₂ levels in the atmosphere.

Dangerous infrastructure builds

The infrastructure needed to make CCS work would also present a risk. Pipelines and other energy-related projects have been known to disrupt local ecosystems, including destroying habitats and displacing wildlife. Additionally, these are also prone to leaks and disruptions, leading to potentially hazardous situations.

Pipelines are vulnerable to earthquakes, landslides, and other natural disasters. According to the Intergovernmental Panel on Climate Change, only 7 to 10% of leaked carbon in the ambient air could pose an immediate threat to human life. Vehicular transport is susceptible to accidents, and ships transporting CO₂ could sink or run aground.

Further dependence on fossil fuels

CCS also has the potential to create a new dependence on fossil fuels. While it is touted as a way to help reduce emissions and slow climate change, it could also incentivise continued use of fossil fuels in the long run. That would continue to put a strain on an already fragile ecosystem.

It incentivises the organisations responsible for the emissions to continue polluting. They can simply pay for carbon capture and storage solutions instead of investing in renewable energy or changing their practices. These practices also cause other forms of pollution, such as fine particles, which are not captured.

Enhanced oil recovery

Most of the active CCS projects are focused on enhanced oil recovery. This practice involves injecting captured CO₂ into existing oil fields, which helps to increase the amount of extractable oil. While this does help reduce emissions from burning that fuel, it also could lead to increased production of fossil fuels in the long run. Said fossil fuel is then sold to consumers who don't have access to CCS, leading to an increase in overall emissions.

Public perception

The public perception of CCS also plays an important role. How will people feel having an invisible gas injected into the ground near their homes? Will they trust that it will be stored safely and without any risk of leakage or escape? How will organisations explain what CCS is to an increasingly worried consumer population? These are all questions that need to be answered.

According to a study by St. Petersburg Mining University in Russia, the public's awareness of such techniques is still lacking.

High costs

It's important to remember that carbon capture storage is not new. Over the years, billions of dollars have been spent on projects worldwide, yet no commercial-scale facility remains. The Petra Nova coal plant in Texas, USA was the most promising commercial CCS power plant but was shut down in 2017 due to underperformance and high costs.

CCS is an expensive endeavour; without concrete evidence of its effectiveness, it is difficult to justify investing billions of dollars into such projects.

Energy intensive

Finally, CCS is energy intensive. In order to capture CO₂ and store it, a second set of infrastructure is needed, which requires its own energy inputs. For instance, the Energy Department recently announced a $12 million fund to improve the efficiency of carbon capture systems. The project aimed to remove 100,000 tons of CO₂ from the air. However, large polluters release a hundred million tons of CO₂ into the atmosphere each year. So, this project alone would only be a drop in the bucket.

The sheer scale of the infrastructure required to capture, compress, and transport CO₂ is daunting. This not only makes it expensive but incredibly energy intensive as well. In fact, one study found that removing 1 billion tons of carbon through direct air capture would require the equivalent of the entire United States' electricity output.