Denmark hopes to pump some climate gas beneath the sea floor

Experts warn that carbon capture and storage is still an unproven technology and relying on it could undermine efforts to decarbonize the energy sector

Denmark pushed the button Wednesday on an ambitious project that aims to bury vast amounts of planet-heating carbon dioxide gas beneath the North Sea floor, in the hope that it can help the Nordic nation and others meet climate targets.

An international consortium including chemicals giant INEOS and gas and oil producer Wintershall Dea said Project Greensand in Denmark's North Sea will be the world’s first cross-border carbon storage project.

Denmark's Crown Prince Frederik gave the symbolic order to begin pumping CO2 into the depleted reservoir of the Nini West oil field, 50 years after his father Prince Henrik celebrated the start of oil and gas exploration off the Danish coast.

“It gives me great pleasure today to be able to reverse the traffic in the pipes and send CO2 back into the Danish underground to the benefit of the climate for Denmark, for Europe, but also for the planet,” said Frederik.

Initially the gas will be shipped in liquid form from an INEOS plant in Belgium, but the plan is to bring in CO2 from Denmark and other European countries later on. After a pilot stage it will see 1.5 million metric tons of the greenhouse gas buried in a sandstone reservoir 1.8 kilometers (1.1 miles) below the seabed each year, rising to 8 million tons per year by 2030.

In a recent report, the United Nations Intergovernmental Panel on Climate Change said carbon capture and storage technology has to be part of the range of solutions to reduce emissions and cap global warming at 1.5 degrees Celsius (2.7 Fahrenheit) compared with pre-industrial times.

“To keep global temperatures below 1.5 degrees we need to remove carbon on top of our efforts to reduce emissions,” European Commission President Ursula von der Leyen said in a video address at the Greensand launch event.