Have you ever wondered? We can feed the world’s population, but how exactly? What happens if we remove all of one kind of animal — will we ever be able to put them back again? Should I travel on buses rather than take the car? Why do some hospitals not allow plants in the hospital wards? Why do some people put lights in greenhouses? Why is there a global ban on whaling? How do fertilisers harm the environment? Can we set up a biosphere on Mars?
