At the foot of the steep slopes of an Icelandic volcanic massif and near the Hellisheiði geothermal power plant, a factory - the largest of its kind in the world - sucks in ambient air to capture CO2, the main cause of global warming, before storing it underground in basaltic rocks for eternity. Now the Swiss frim says it has certifiably extracted CO2 from the air and permanently stored it in the ground, for the first time on behalf of paying customers, including Microsoft. FILE IMAGES