The Doomsday Clock, a symbol that conveys "how close we are to destroying our civilization with dangerous technologies of our own making," has moved from five minutes to three minutes before midnight.
The announcement was made Thursday by the Bulletin of the Atomic Scientists, a group founded in 1945 by University of Chicago scientists who helped develop the first atomic weapons in the Manhattan Project.
Each year, the group's Science and Security Board decides whether to move the minute hand of the clock closer or further away from midnight -- aka Doomsday -- or to leave it in place.
This year, the combined threat of "unchecked climate change, global nuclear weapons modernizations, and outsized nuclear weapons arsenals" convinced the Bulletin scientists to push the minute hand up, the group reported on its website Thursday.
In 2015, these developments "pose extraordinary and undeniable threats to the continued existence of humanity, and world leaders have failed to act with the speed or on the scale required to protect citizens from potential catastrophe," the group says. "These failures of political leadership endanger every person on Earth."
The last time the clock was so close to midnight was in 1984, when "a major defense build-up that included the pursuit of a potentially destabilizing ballistic missile defense system, relations between the United States and the Soviet Union reached an icy nadir," the Bulletin says.
"Today, more than 25 years after the end of the Cold War, the members of the Bulletin of the Atomic Scientists Science and Security Board have looked closely at the world situation and found it highly threatening to humanity -- so threatening that the hands of the Doomsday Clock must once again be set at three minutes to midnight, two minutes closer to catastrophe than in 2014."
2014 was the hottest year on record, the Bulletin notes. Additionally, it notes, nine of 10 hottest years on record have occurred since 2000.
Though some "modestly positive developments" have been made in the arena of climate change and in the advancement of renewable energy technologies, current efforts remain "entirely insufficient to prevent a catastrophic warming of Earth," it warns.
"Absent a dramatic course correction, the countries of the world will have emitted enough carbon dioxide and other greenhouse gases by the end of this century to profoundly transform Earth's climate, harming millions upon millions of people and threatening many key ecological systems on which civilization relies."
Meanwhile, "efforts to reduce world nuclear arsenals have stalled. The disarmament process has ground to a halt, with the United States and Russia embarking on massive programs to modernize their nuclear triads -- thereby undermining existing nuclear weapons treaties -- and other nuclear weapons holders joining in this expensive and extremely dangerous modernization craze."
The Bulletin asks the political leaders of the world "to take coordinated, quick action to drastically reduce global emissions of heat-trapping gases, especially carbon dioxide, and shrink nuclear weapons arsenals."
It also asks the citizens of the world "to demand action from their leaders. The threat looms over all of humanity. Humanity needs to respond now, while there is still time."
[Vinnie Rotondaro is NCR national correspondent. His email address is firstname.lastname@example.org.]