Guardian: Engineers in Iceland are set to convert carbon dioxide to solid rock as a way to tackle global warming. The experts want to exploit the country’s volcanic origins to dispose of up to 30,000 tonnes of the greenhouse gas each year. They expect the gas to react with layers of volcanic rocks deep beneath the surface to form minerals that will lock the carbon pollution away for millions of years. “This is a well-known natural process,” said Holmfridur Sigurdardottir, project …