Scientists have come up with a smart but simple way to deal with carbon dioxide emissions, by turning them back into stone. Researchers in Iceland pumped 220 tons of CO2 deep underground into volcanic rock. It reacted with minerals in the rock and over a relatively short space of time, transformed into a chalk-like solid substance similar to limestone. The team expressed their surprise at both the success and the speed of the CO2 conversion. Lead scientist Juerg Matter said: "Of our 220 tons of injected CO2, 95 per cent was converted to limestone in less than two years." He added: "It was a huge surprise to all the scientists involved in the project, and we thought, 'Wow! This is really fast'.