BBC: Sea urchins create their shells by using the metal nickel to turn carbon dioxide into calcium carbonate. In an article published in the journal Catalysis Science and Technology, Gaurav Bhaduri and Lidija Šiller of Newcastle University in the UK propose that a similar technique could be used to capture and store carbon generated in power and chemical plants. Current plans call for pumping the gas into underground storage, but there is a strong possibility that some of it could leak back into the environment. To avoid that, a method has been proposed to lock up the CO₂ using an enzyme called carbon anhydrase, but it is extremely expensive. To be able to use nickel instead, as the sea urchins do, would be much cheaper and more environmentally sound.