Guardian: It has long been the holy grail for those who believe that technology can save us from catastrophic climate change: a device that can “suck” carbon dioxide (CO2) from the air, reducing the warming effect of the billions of tonnes of greenhouse gas produced each year. Now a group of US scientists say they have made a breakthrough towards creating such a machine. Led by Klaus Lackner, a physicist at Columbia University in New York, they plan to build and demonstrate a …