The Doomsday Clock, a figurative timepiece used as a barometer of humankind’s fate, was moved one minute closer to midnight on Tuesday, the first time it has been nudged forward since 2007. It is now 11:55, five minutes before the appointed hour. 

The re-setting of the clock has become something of a gimmick in recent years, carried out by the Bulletin of the Atomic Scientists, a group established to raise awareness about the perils of nuclear weaponry, and aimed at warning the public about various catastrophic dangers.

But the process involved in deciding the time is a deeply serious one, overseen by a venerable board of scientists, Nobel laureates and others and concluded with a symposium in Washington. The setting of the clock is no longer based only on the proliferation of nuclear arms, but also on threats such as climate change and biological weaponry.