Doomsday is three ticks of the Atomic Clock's minute hand from arrival.

The Bulletin of the Atomic Scientists moved the metaphoric clock to 11:57, the closest it has been to midnight since 1984 and the first time since the clock was changed since 2012. "Doomsday Clock" operators pushed forward the minute hand because of concerns over climate change and world leaders not properly addressing them.

The Bulletin made its announcement Thursday at 1600 GMT (11:00 a.m. EST).

"In 2015, unchecked climate change, global nuclear weapons modernizations, and outsized nuclear weapons arsenals pose extraordinary and undeniable threats to the continued existence of humanity," the group said in a statement, according to USA Today. "World leaders have failed to act with the speed or on the scale required to protect citizens from potential catastrophic.

"These failures of political leadership endanger every person on Earth."

The Doomsday Clock originated with scientists who worked on the Manhattan Project to build atomic bombs during World War II. In 1953, the Bulletin placed the clock's minute hand at two minutes from midnight in response to hydrogen bomb testing.

The last time the clock moved was 2012 when the Bulletin placed it at 11:55. According to CBS News, that was over concerns of nuclear arsenals in various parts of the globe. That lingering threat contributed to the 2015 decision.

"Human influence on the climate system is clear," the Bulletin's Richard Somerville said during the conference. "Each of the last three decades has been successively warmer than any preceding on record."