Scientists have come up with  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  rock and over  relatively short space of time, transformed into  chalk-like solid substance similar to limestone.  team expressed their surprise at both  success and  speed of  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  huge surprise to all  scientists involved in  project, and we thought, 'Wow! This is really fast'." 
 scientists hope their experiment will be adapted on  larger, more industrial scale. It could help to alleviate  problem of growing CO2 emissions entering  atmosphere and warming  planet. It could also become  key technique in carbon capture and storage (CCS) solutions. Many other CCS techniques have involved injecting and trapping CO2 underground. However, there was always  problem of the emissions leaking their way back above ground and into  atmosphere. Dr Matter was enthusiastic about his team's experiments. He said: "We need to deal with rising carbon emissions and this is  ultimate permanent storage – turn them back to stone."