[This essay is excerpted from Noam Chomsky's new book, Who Rules the World? (Metropolitan Books).]

In January 2015, the Bulletin of the Atomic Scientists advanced its famous Doomsday Clock to three minutes before midnight, a threat level that had not been reached for 30 years. The Bulletin's statement explaining this advance toward catastrophe invoked the two major threats to survival: nuclear weapons and "unchecked climate change." The call condemned world leaders, who "have failed to act with the speed or on the scale required to protect citizens from potential catastrophe," endangering "every person on Earth [by] failing to perform their most important duty — ensuring and preserving the health and vitality of human civilization."

Since then, there has been good reason to consider moving the hands even closer to doomsday.

As 2015 ended, world leaders met in Paris to address the severe problem of "unchecked climate change." Hardly a day passes without new evidence of how severe the crisis is. To pick almost at random, shortly before the opening of the Paris conference, NASA's Jet Propulsion Lab released a study that both surprised and alarmed scientists who have been studying Arctic ice.