The world faces two existential threats: climate change, and nuclear Armageddon. Action on both is required urgently. Tackling the first will impose significant economic costs and lifestyle adjustments, while tackling the second will bring economic benefits without any lifestyle implications.

Those who reject the first are derided as denialists; those dismissive of the second are praised as realists. Although action is needed now in order to keep the world on this side of the tipping point, a climate change-induced apocalypse will not occur until decades into the future.

A nuclear catastrophe could destroy us at any time, although, if our luck holds out, it could be delayed for another six decades. The uncomfortable reality is that nuclear peace has been upheld, owing as much to good luck as to sound stewardship.