How we can transform our energy system to achieve net-zero emissions

TURN on the nearest switch. You won’t notice anything different; that is kind of the point. Yet in many places, there is a better chance than ever that the electricity coming out of the socket was generated by clean, renewable sources such as solar panels and wind turbines.

That is progress, of a sort. In most countries, however, most electricity still comes from climate-polluting, fossil-fuel sources. Your heating, too, almost undoubtedly uses fossil fuels, as does your car, if you have one. Most goods you buy require fossil fuels to make them and transport them to the shop or…