Scientists Lawrence Krauss (left) and Robert Rosner (middle) and international affairs expert Sharon Squassoni (right) unveiled an updated Doomsday Clock, which the Bulletin of the Atomic Scientists has updated yearly since creating it in 1947. THOM WOLF/BULLETIN OF ATOMIC SCIENTISTS

The world is closer to nuclear annihilation than at any point since the first hydrogen bombs were tested in the early 1950s, says a group of scientists who monitor global tensions.

The Bulletin of the Atomic Scientists announced today that it has moved its Doomsday Clock to 2 minutes before midnight, citing North Korea's recent tests of missiles and nuclear weapons and the world's lack of progress in confronting climate change.

"In 2017, we saw reckless language in the nuclear realm heat up already dangerous situations and relearned that minimizing evidence-based assessments regarding climate and other global challenges does not lead to better public policies," said Rachel Bronson, the Bulletin's president and CEO in Chicago, Illinois. Last year the clock moved half a tick, from 3 minutes to 2.5 minutes before midnight; it has been in single digits since India and Pakistan staged back-to-back nuclear weapons tests in 1998.

"In 2017, we saw reckless language in the nuclear realm heat up already dangerous situations and relearned that minimizing evidence-based assessments regarding climate and other global challenges does not lead to better public policies," said Rachel Bronson, the Bulletin's president and CEO in Chicago, Illinois. Last year the clock moved half a tick, from 3 minutes to 2.5 minutes before midnight; it has been in single digits since India and Pakistan staged back-to-back nuclear weapons tests in 1998.

Trump bears blame for being "unable to develop, coordinate, and clearly communicate a coherent foreign, much less nuclear, policy," said Robert Rosner, an astrophysicist at the University of Chicago. The panel cited a dearth of diplomats and Trump's October 2017 decision not to certify that Iran was in compliance with an international agreement to throttle back its nuclear weapons program.

The Bulletin scientists said worsening effects from climate change have also increased the risk of global annihilation, citing destructive hurricanes in the Caribbean, heat waves around the globe, wildfires in the United States and Canada, rising greenhouse gas emissions, and declining Arctic ice cover.

Are things today as bad as in 1953, when both the United States and Russia exploded thermonuclear bombs? Comparisons are difficult, Bronson says, but there are more nuclear weapon states today than in the 1950s. "We've made the clear statement that we feel the world is getting more dangerous. ... We present the clock not so much as doom and gloom, but as an opportunity to get government and the public discussing the important issues," adds physicist Lawrence Krauss of Arizona State University in Tempe.

A Doomsday Clock report by the Bulletin scientists suggests ways world leaders can step back from the brink, starting with Trump ignoring Kim Jong-un's provocative rhetoric. But because leaders and governments have proved ineffective at easing many threats, says Sivan Kartha of the Stockholm Environment Institute, moving the clock back will require the public to "compel their leaders to once again respect scientists, heed the facts, and make rational choices that move us further from the brink."