For the past decade north eastern Nigeria, and the areas around Lake Chad, have been beset by violent confrontations between the state and Boko Haram as well as armed kidnappers. One of the cruellest outcomes has been the abduction of school children. Hakeem Onapajo explains the research he’s done into why children have become targets. Among the factors he identified were that kidnappings attracted local and international attention. And they were useful in negotiating the release of terrorists imprisoned by authorities, and collecting huge ransoms.

A mile below the surface of the Greenland ice sheet, an ancient Arctic ecosystem is preserved in the frozen soil. How scientists discovered its leaves, twigs and mosses is a story in itself. It starts with a secret military base built into the northern Greenland ice. Scientists Andrew Christ and Paul Bierman describe the discovery as something of a Rosetta stone for understanding how well the ice sheet stood up to global warming in the past – and how it might respond in the future.