Coral reefs are among the most beautiful habitats in the world. As well as being rich in biodiversity, they're vital for the local economies that depend on them for fishing, tourism or protection from storms.While most of us are aware that ocean acidification is bad for coral reefs, scientists are now finding that coral communities are facing other threats from climate change.Richard Hollingham meets three coral reef experts to find out more - not in some tropical paradise but in the basement of a 1960s towerblock at the University of Essex.Later in the programme we hear from two insect experts at the University of Cambridge, who explain why it might be wise for oil palm producers to nurture patches of rainforest close to and among their plantations.We also find out why scientists think an asteroid caused the extinction of the dinosaurs, rather than huge volcanoes, why global warming could lead to more male turtles than female turtles and how household waste is being linked with pollution in rivers.