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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."

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