Denmark, which was the first country in the world to bury CO2 imported from abroad, on Wednesday inaugurated a carbon dioxide storage site 1,800 meters under the North Sea, a tool considered essential to curb global warming. a new green chapter for the North Sea", celebrated Prince Frederick, as he launched the pilot phase of the project in Esbjerg.
Paradoxically, this CO2 graveyard is an old oil field that contributed to the emissions. Led by the British chemical multinational Ineos and the German energy company Wintershall Dea, the "Greensand" project will allow up to eight million tons of CO2 to be stored per year until 2030.
Still in its infancy and very expensive, carbon capture and storage (CCS) consists of capturing and then trapping CO2, the main cause of global warming. There are currently more than 200 projects operating or under development around the world.
What makes Greensand special is that, unlike existing sites that sequester CO2 from neighboring industrial facilities, it uses carbon from afar. "It is a European achievement in terms of cross-border cooperation: CO2 is captured in Belgium and very soon in Germany, loaded by ship in the (Belgian) port of Antwerp," said European Commission President Ursula von der Leyen.
The gas is transported by sea to the Nini West platform, at the edge of Norwegian waters, and transferred to a reservoir 1.8 km deep. For the Danish authorities, who aspire to carbon neutrality by 2045, it is an "indispensable instrument in our climate toolbox".
The North Sea is a region ripe for burial because it is home to many pipelines and geological reservoirs that have been left empty by decades of oil and gas production.
"Depleted oil and gas fields have many advantages because they are well documented and infrastructure already exists that can most likely be reused," says Morten Jeppesen, director of the Center for Marine Technologies at the Danish University of Technology.
Near Greensand, the French giant TotalEnergies is going to explore the possibility of burying more than two kilometers under the seabed some 5 million tons of CO2 per year until 2030. A pioneer of CCS, neighboring Norway will also receive tons of liquefied CO2 from Europe in the next years. The main producer of hydrocarbons in Western Europe, the country also has the largest CO2 storage potential on the continent.
The quantities stored remain small relative to the magnitude of the emissions. According to the European Environment Agency, the European Union emitted 3.7 billion tons of greenhouse gases in 2020, a low level for being a year affected by the pandemic.
Long perceived as a technically complicated and expensive solution, CCS is now seen as necessary, both by the Intergovernmental Panel on Climate Change (IPCC) and the International Energy Agency. But it is not a silver bullet to global warming.
The energy-intensive process of capturing and storing CO2 emits the equivalent of 21% of the gas captured, according to Australian think tank IEEFA. And the technique involves risks, the research center warns, citing the risk of leaks with catastrophic consequences.
Among environmental advocates, the technology does not have unanimous support. "It doesn't solve the problem and it prolongs the harmful structures," says Helene Hagel, energy officer at Greenpeace Denmark. "The method does not change our deadly habits. If Denmark really wants to reduce its emissions, it must address the sectors that produce a large part of it, namely agriculture and transport," she said.
