Tobacco still kills six million people around the world every year.
Despite huge public health efforts to help people quit and prevent young people starting, smoking remains the single greatest cause of ill health and premature death.
And even with restrictions on tobacco advertising and smoking in public places, many young people continue to take up smoking.
The situation is even worse in poorer countries, where support to stop smoking is limited, and tobacco control policies weaker.
So in light of this, how should we view the increasing popularity of electronic cigarettes?
The vastly reduced number of chemicals present in e-cigarette vapour compared to tobacco smoke