Denmark starts seabed carbon-storage project

Denmark plans to store huge quantities of the greenhouse gas carbon dioxide, or CO2, under the North Sea, in the latest in a flurry of initiatives aimed at reducing the amount of the harmful material in the atmosphere.

The northern European nation started work on Project Greensand on Wednesday, via an international consortium that includes chemicals giant INEOS and gas and oil producer Wintershall Dea.

The gas will be stored in the now-exhausted former Nini West oil field.

Denmark's Crown Prince Frederik launched Project Greensand on Wednesday, 50 years after his father, Prince Henrik, kicked off gas and oil exploitation off the nation's coast.

The Independent news website quoted Frederik as saying: "It gives me great pleasure … 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."

The project calls for captured CO2 from Denmark and beyond to be turned into liquid for shipping before being trapped 1.8 kilometers below the seafloor. Eventually, the facility will accept 8 million metric tons of the gas every year.

The project will help the 27-nation European Union strive for its climate change targets. It has said it needs to eventually be capturing and storing about 300 million metric tons of CO2 annually.

But while CO2 capture and storage is preferable to leaving it in the atmosphere, critics say it is akin to applying a sticking plaster to the problem and that people should focus on creating less gas by reducing fossil fuel use. Additionally, gas storage facilities could release vast amounts of CO2 back into the atmosphere in the event of an earthquake. Also, many current CO2 capture projects use a lot of energy, which contributes to the creation of more gas.

These problems make the claims of a group of scientists behind an article in the latest edition of the journal Science Advances particularly appealing.

The group claims to have found a way to absorb CO2 three times more efficiently than current methods. The scientists also say they can turn the gas into bicarbonate of soda cheaply, which can be stored safely and easily in seawater.

The study's lead author, Professor Arup SenGupta from Lehigh University in the United States, said the method relies on a material that absorbs the gas.

The BBC quoted him as saying: "This simple ability to capture CO2 at a high quantity, in a small volume of material, is a unique aspect of our work."

SenGupta said the technology means a ton of CO2 can be removed for less than $100, which he said will be especially welcome in developing countries.