Climate change and the surgeon: what is the problem? Why is it so hard? What can be done?

We know very well what causes climate change, and in general terms, what the dangers are. This is a new kind of environmental problem, it is not like taking lead out of petrol, and it is important to understand why responding to climate change is so challenging. But that is no reason to give up: in fact there are many opportunities to intervene, including actions that can be taken by surgeons and other health professionals.