For those of us who grew up during the 40-year conflict known as the Cold War, the resonances of ‘duck and cover’ routines at school catapult us between the fear of another world war and the hope that out of this conflict will emerge not only a free Ukraine, but also a globally unified and urgent response to two existential threats the world faces today. The first, stockpiles of nuclear weapons, a legacy of the Cold War, and the second, the world's dependence on fossil fuels, one that might be curbed using lessons from the Cold War.