A wave of proposals to pool carbon dioxide from fossil fuel and other industrial activities and bury it beneath the oceans could pose a massive risk to seabeds and aquatic ecosystems, the Center for International Environmental Law (CIEL) warns in a report issued last week.
“This untested technique, which involves a step change in the scale and complexity of offshore CCS (carbon capture and storage), poses uncalculated risks,” CIEL writes in a summary of the report. “Some of the envisioned hubs are associated with the buildout of new fossil fuel projects, and most would store waste from industries that must be scaled down or phased out if the world is to avoid catastrophic climate change.”
CCS is already a questionable enough technique on land, CIEL says—echoing the industry’s own assertions that the technology won’t likely be viable at scale by 2035. But that track record “has not stopped polluters from touting the promise of CCS and the possibility of turning the seabed into a storage site for their CO2 waste,” the report warns [pdf]. Those plans represent “a new threat to the world’s oceans and a dangerous distraction from real progress on climate change.”
The report says it’s risky to pool carbon dioxide from multiple industrial sources at a single storage site, and the plan to inject the collected emissions into subsea storage hubs is largely untested. “Combining various CO2 streams with different types of impurities could pose technical challenges and risks to infrastructure that may endanger projects’ feasibility, as well as their safety,” it states. Global experience so far is limited to two projects in Norway, “both of which encountered unpredicted problems despite their relatively simple designs and small scales.”
CIEL foresees multiple risks in injecting CO2 into seabeds, and cautions that methods of monitoring the practice are as yet untested. “Whether onshore or offshore, injecting CO2 under the Earth’s surface has the potential to contaminate groundwater, cause earthquakes, and displace deposits of brine, which can be toxic,” the report says. “These risks have never been confronted at scale, and the magnitude of offshore injection contemplated by proponents would create unprecedented challenges in managing reservoir pressure and monitoring CO2 plumes in the depths of the ocean.”
Those risks would only put more pressure on ocean ecosystems that are already at the brink, largely thanks to pipeline and shipping leaks and decommissioned infrastructure associated with fossil fuel production. “The push for offshore CCS reflects the same attitude that has left the oceans in crisis today: treating them as a limitless resource to exploit and a bottomless receptacle for humanity’s waste,” CIEL writes.
“Given the myriad uncertainties and hazards associated with capture, transport, and injection of CO2, and the technology’s history of failure, the precautionary principle weighs heavily against approving offshore CCS,” CIEL Climate and Energy Program Director Nikki Reisch said in an emailed statement. “Rather than subsidizing schemes that claim to ‘manage’ fossil fuel emissions, governments should be supporting strategies to prevent fossil fuel pollution at the source, and aimed at ending reliance on oil, gas, and coal.”
She added that the path to preventing the impacts of offshore carbon storage is already well laid out.
“Preventing polluters from turning the ocean floor into a disposal site for fossil fuel industry waste does not require new treaties or international agreements,” she wrote. “Existing laws at the local and national levels provide a crucial first line of defence, undergirded by established international ocean protections. Environmental impact assessment, marine and species protection, biodiversity conservation, and health and safety regimes can and should be leveraged to protect against the threat of offshore CCS and put the brakes on the buildout of risky carbon capture projects.”