It s another hot day in Mali, at the edge of the desert, and Mariam and Issa know something special is about to happen. As they play in the shade and make clapping rhythms with their hands, Mum and Dad make their own kind of music with shovels, poking holes in the dry earth. When Uncle Cedric arrives, the children ask him what all the plants and baby trees in the back of his car will be for. The future, he says, with a smile. Taking part in creating...