A 'concrete' solution to climate change

Many of the new solutions to flight climate change sound almost impossible. What if a machine could suck planet-warming carbon dioxide out of the air and store the gas forever inside concrete bridges and buildings?

Well, that’s happening. Last month, in the city of Tracy, California, the U.S. energy secretary joined a group of very excited scientists and corporate executives to celebrate a milestone: the country’s first commercial-scale direct-air capture, or DAC, facility.