The results are published in PNAS. "Every year we go back to the dome area with our research vessel, and every year I am anxious to see if one of these domes has become a crater," says lead author of ...

In New Delhi, the heat is oppressive, with burning pyres of rubbish assaulting your nose. In São Paulo and Beijing, thick smog shrouds the city and stings your eyes. In London, the diesel engines of ...