The first of two programmes about nuclear winter. In 1983, Toon, Turco,
Ackerman, Pollack and Sagan alerted the world to the danger of nuclear winter: that nuclear war might kill more people by its effects on the climate than by blast and radiation.
Colin Tudge teases out the details of their predictions and compares them with those of the scientists who prefer to think of nuclear autumn. Producer NICHOLAS MORGAN