One of the two duties of a doctor laid down by the General Medical Council of the United Kingdom is “to protect and promote the health of . . . the public.”1 Should this duty extend to working to prevent climate change? We believe it should.

Climate change leads to the extinction of species. During the past 500 million years—a mere 10th of the world's history—five major and many minor events have caused extinctions. The last major event eliminated the dinosaurs 65 million years ago. An extraterrestrial object 10 km in diameter slammed into what is now the Yucatan peninsula, Mexico. It caused firestorms, a tsunami 1 km high, planet wide darkness for months, and an extended period of carbon dioxide induced global warming. Within a few months of the event, the 150 million year reign of the dinosaurs was …