There has arguably never been a more critical moment in the history of communication between scientists and those in power than 1939. Physicists had demonstrated nuclear fission. Some speculated that uranium could be harnessed to trigger a chain reaction, unleashing the vast stores of energy locked inside the atom, and that this energy could be channeled to build a bomb with unprecedented destructive force.

The story of how a few prescient scientists convinced President Roosevelt of the danger and potential of the atom bomb is a fascinating case study, riddled with delays, uncertainties, and miscalculations that could be a cautionary tale for climate communicators. Many of the lessons to be drawn from that iconic episode almost 70 years ago echo themes familiar to climate change communicators.

What follows is an attempt to illuminate today's very different scientific urgency within this highly contrasting framework. The hope is that both the differences in context and substance and the sometimes-surprising similarities may provoke reflection on the difficulties of communicating the threats inherent in world-altering risks – the atom bomb on the one hand and the more slowly ticking time-bomb of climate change on the other.

In the narrow context of the story below, the communications campaign was a success – the scientists persuaded the government to build the bomb and, some argue, shortened the Second World War as a consequence.