The Doomsday Clock - a barometer¹ of nuclear danger for the past 55 years - has been moved one minute further away from the "midnight hour".

“末日时钟”——过去55年核危险的晴雨表——被从“午夜时分”再向前提前了一分钟。

The Doomsday Clock has shifted to six minutes before midnight

The concept timepiece计时器, devised by the Bulletin公告，公报 of the Atomic Scientists (BAS) now stands at six minutes to the hour.

The group said it made the decision to move the clock back because of a more "hopeful state of world affairs".

The clock was first featured by the magazine in 1947, shortly after the US dropped its A-bombs on Japan.

The clock had been adjusted 18 times before today since its initial start at seven minutes to midnight.

Most recently, in January 2007, the clock moved to five minutes to midnight, when climate change was added to the prospect² of nuclear annihilation消灭，灭绝 as the greatest threats to humankind.

The concerns then included Iran's nuclear ambitions野心，抱负 and the inability to halt the international trafficking of nuclear materials such as highly enriched uranium and plutonium钚.

See how the clock has changed

Two years later, however, the board of the BAS says that there is now a "growing political will" to tackle both the "terror of nuclear weapons" and "runaway³ climate change".

At a news conference in New York, the BAS board said: "By shifting the hand back from midnight by only one additional minute, we emphasize how much needs to be accomplished⁴, while at the same time recognizing signs of collaboration⁵ among the United States, Russia, the European Union, India, China, Brazil, and others on nuclear security and on climate stabilization⁶."

But Lawrence Krauss, co-chair of the BAS board of sponsors, warned scientists that there was still much to be done.

"We urge leaders to fulfill⁷ the promise of a nuclear weapon-free world and to act now to slow the pace of climate change," he said.

"We are mindful of注意，留心 the fact that the clock is ticking," he added.

The Bulletin of the Atomic Scientists, founded by former Manhattan Project physicists⁸, has campaigned for nuclear disarmament since 1947.

Its board periodically reviews issues of global security and challenges to humanity, not solely⁹ those posed by nuclear technology, although most have had a technological¹⁰ component¹¹.