CROWDSCIENCE

8.30PM, WORLD SERVICE HHH The idea of living in a tree house is a childhood dream that never loses its charm. The fairytale image of a rope ladder leading up to a front door, with rooms among leafy branches, is very appealing. The dream, for some, is a reality; Britain has quite a few of these leafy homes and, as we hear in this report, a project is under way to make a threestorey house of living eucalyptus trees in Addis Ababa, Ethiopia.