The Right Way to Achieve Net-Zero Greenhouse Gas Emissions Target?

December 4, 2023

The oceans are not a bottomless receptacle for humanity’s waste: Switzerland’s misguided approval of the export of CO2 into sub-seabed storage.

With the many developments hitting the news, including the Climate Change Conference (COP28) in December 2023, some decisions with significant consequences haven’t made it into the news or fallen under the radar of public attention. OceanCare is providing one example in that respect.

At its meeting on 22 November 2023, the Swiss Federal Council ratified the 2009 amendment to the London Protocol, which permits storing CO2 extracted via carbon capture or capture removal technologies in the seafloor. This ratification is part of the Swiss Government’s well-meaning strategy to achieve its long-term net-zero greenhouse gas emissions target. The government, as well as industry, are excited about the potential for this technology to compensate where emissions reduction is insufficient for Switzerland to reach net-zero, especially in those hard-to-abate industries, such as the cement industry. But any such enthusiasm is premature.

Do we talk about large scale successfully tested technologies?

At present carbon capture is unproven, carbon removal is unproven, and carbon storage is unproven, and, if anything, each of these technologies provide a cautionary tale, particularly in light of the massive future expansion that would be required to meet the world’s climate targets.

Carbon capture is generally carried out at the point of emissions, such as a steel plant. It is the process of separating a relatively pure stream of carbon dioxide (CO2) from industrial and energy-related sources before compressing and transporting it to storage. Although, to date, this process has captured significantly more CO2 than carbon removal processes, no projects have met their targets and many have been abandoned due to high energy and resource costs. Only one coal plant in the United States ended up using carbon capture on a large scale: The $1 billion Petra Nova facility in Texas, completed in 2017, which ironically sold the captured CO2 to oil drillers that injected the gas into oil fields to extract more crude oil.

Carbon removal on the other hand attempts to pull CO₂ out of the atmosphere. However, the CO₂ in the atmosphere only makes up 0.04% of the atmosphere, which makes its removal even more difficult. There are many proposed techniques to remove CO₂ from the atmosphere but chemical reactions are often involved. Swiss company, Climeworks, is one the most advanced of the carbon removal hopefuls. Currently, Climeworks only removes 4,000 tonnes of CO2 from the air, equivalent to three seconds of humanity’s annual emissions. Carbon removal uses vast amounts of energy, water and chemicals, and Climeworks is only able to be emissions negative by utilising very rare geothermal energy in Iceland, that would likely be better utilised to replace existing fossil fuel use in the first place. At the scales envisaged for carbon removal to play a meaningful role in the future i.e. removing 10 gigatonnes of CO2 per year, would require an amount of energy equivalent to current total global electricity production.

Captured and stored, but where?

In the Swiss case, the federal government estimates approximately a quarter of current CO₂ emissions will need to be either captured (7 million tonnes of CO2 per year) or removed from the atmosphere using technology (5 million tonnes of CO2 per year). The government wants to store the CO₂ captured in Switzerland domestically wherever possible. However, it considers the potential to be limited because it is not clear whether there are enough suitable geological storage sites that can be developed economically.

Indeed, whether carbon capture or carbon removal, the transport and storage needs are the same. In terms of transport, storage at scale would require such vast fleets of vehicles as to be insurmountable. This means instead a giant network of pipelines will need to be constructed across Europe, the United States and likely anywhere else significant emissions occur. On each continent, this network of pipelines to transport CO2 will need be tens of thousands of kilometres in length, requiring huge investment, energy and emissions footprint to construct, and creating further fragmentation and perturbation of the landscape.

Stored and out of sight?

Once the product reaches its destined CO2 terminal in the North Sea or elsewhere, it needs to be pumped into the seafloor.  Global experience with this technology is so far limited to two relatively simple and small-scale projects in Norway (Sleipner and Snøhvit) both of which cast doubt on whether the world has the technical prowess, strength of regulatory oversight, and unwavering multi-decade commitment of capital and resources needed to keep carbon dioxide sequestered below the sea.

The Sleipner CCS project began in 1996, each year injecting between 850,000-1,000,000 tonnes of gaseous CO2 into deep rock layers more than 1 km under the seabed. In 1999 CO2 began unexpectedly migrating in large amounts into a previously unknown upper layer where it has so far remained trapped under the caprock layer. Although the thick rock layer has so far prevented the gas escaping, the horizontal boundaries of the unidentified layer are unknown and could mean that the CO2 will continue move unpredictably and out of control, with a real risk of leakage. The other CCS project, Snøhvit, commenced CO2 injections in 2008 and was intended to have a capacity for 18 years’ worth of emissions. However, after only 18 months of operation, pressure in the storage space rose precipitously risking geological failure and requiring storage operations to be suspended and plugged. This experience has demonstrated that the practice of putting CO2 back into the ground can deviate substantially from predictions and that should the process fail, costly recovery action will need to be rapid to avoid a catastrophe.

Both onshore and offshore, injecting CO2 under the Earth’s surface has the potential to contaminate groundwater, cause earthquakes, and induce release of carbon trapped at depth; risks that multiply at the scales proposed to store billions of tonnes of captured and removed CO2. From a marine perspective, the establishment, injection, potential failure, or recovery of any failure events will all pose severe local- and possibly broad-scale impacts including via pollution, underwater noise and mechanical disturbance. Given the technology’s history of failure, doing so would inevitably put more pressure on ocean ecosystems that are already at the brink. Instead, environmental impact assessment, marine and species protection, as well as health and safety regimes should all be leveraged to protect against the threat of seabed storage of CO2.

Delaying tactic as a business model?

Perhaps unsurprisingly, aside from national governments, the oil and gas industry are already well-embedded in such ventures. The “Northern Lights” Norwegian storage project includes Equinor, Shell and Total and aims to provide large storage capacities under the seabed for European CO₂ emitters from 2025. Instead of subsidising such schemes that help prolong the fossil fuel age, governments should be preventing fossil fuel pollution in the first place, by ending reliance on oil, gas, and coal, and avoiding risky and expensive distractions.

The final analysis is therefore clear, if we don’t immediately and radically alter our dependence on fossil fuels, billions of tonnes of CO2 would need to be stored every year by 2050. What remains unclear is whether this scale could be achieved, and even if it could be achieved, whether doing so would present even greater risk to humanity and life on this planet.

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