The Bulletin of the Atomic Scientists has taken the unprecedented step of moving the Doomsday Clock ahead 30 seconds, taking the world to two-and-a-half-minute to midnight. The scientists said Thursday that several factors weighed heavily in their decision, particularly climate change denial by people in power -- they cited U.S. President Donald Trump -- and talk about more nuclear weapons. From a report on NPR: The setting is the closest the clock has come to midnight since 1953, when scientists moved it to two minutes from midnight after seeing both the U.S. and the Soviet Union test hydrogen bombs. It remained at that mark until 1960. "Make no mistake, this has been a difficult year," Rachel Bronson, executive director and publisher of the Bulletin of the Atomic Scientists, said as the new setting was announced Thursday.