Explanation:

• Till now carbon capture and sequester, or CCS, was seen as a potentially significant way to combat climate change. The idea is that storing CO2 emissions underground would prevent the greenhouse gas from entering the atmosphere. Most experiments involve pumping CO2 into sandstone or deep aquifers, though there are concerns that the gas could eventually escape and reenter the atmosphere — whether through human error or seismic activity.

• Experiment of converting Co2 into stone is called Carbfix. In this experiment, Co2 was injected into a deep well in Iceland.

• As a volcanic island, Iceland is made up of 90 per cent basalt, a rock rich in elements such as calcium, magnesium and iron that are required for carbon mineralisation. The CO2 is dissolved in water and carried down the well. On contact with the target storage rocks, at 400-800 metres under the ground, the solution quickly reacts with the surrounding basaltic rock, forming carbonate minerals.