From the BBC World Service: Set against a backdrop of political turmoil, it’s going to be a big ask for the leading rich and developing nations to sign up to any meaningful declarations. In India’s capital, Delhi, restrictions are being tightened on construction and vehicles — air quality has become so bad that a blanket of toxic smog is covering the city. And we visit Madagascar, off the coast of southern Africa, where we look at some solutions to wide-scale environmental damage.
