The Doomsday Clock whose minute-hand cast a long, Damoclean shadow through the final years of the Cold War was restarted late last year by the Intergovernmental Panel on Climate Change (IPCC) warning that the world had 12 years left to move global decarbonisation meaningfully forward to avoid the most catastrophic impacts of climate change.

But there is fundamental difference in the realities that were facing the world then and now.