Eight billion tons of concrete are used for construction each year worldwide. To create space for new buildings, old ones are torn down. Most of the concrete ends up in waste dumps. And the environment suffers already when the mixture of water, gravel, and cement is manufactured: up to 15 per cent of the world’s annual carbon dioxide emissions arise from cement production. An idea developed by Fraunhofer researchers helps recycle component parts of concrete. Under water, bolts of lightning strike the concrete and split it up. This method can also be used to dismantle nuclear power plants, as even radioactive building rubble can be reduced.