Mark your calendars: We’re 30 seconds closer to Doomsday.

No, we aren’t joking, and the U.S. is mostly to blame.

The Doomsday Clock, a project created by the Bulletin of the Atomic Scientists in 1947 during the Cold War nuclear arms race, measures just how close humans are to destroying the world, based on our management of critical technologies.

And now, the clock hands have been moved 30 seconds forward, to two minutes to midnight — only the second time it’s ever been this close to utter apocalypse. The previous time the clock got this close was in 1953, at the peak of the Cold War when the U.S. and Soviet Union tested hydrogen bombs. It’s moved 25 times since 1947. The furthest it’s been away from an apocolyspe is 17 minutes, in 1991 when the Cold War ended.

The group of scientists said they moved the clock hands “because of the extraordinary danger of the current moment,” and their statement largely cites U.S. behavior.

Most prominently is the sharp rise in tensions between President Trump and North North Korea’s Kim Jong Un through a series of incendiary tweets in recent months. And the journal does not hold back in calling them both out directly, noting the “downward spiral of nuclear rhetoric between U.S. President Donald Trump and North Korean leader Kim Jong Un.”

“In 2017, we saw reckless language in the nuclear realm heat up already dangerous situations and re-learned that minimizing evidence-based assessments regarding climate and other global challenges does not lead to better public policies,” according to the statement following the announcement.

The journal also notes the future of the Iran nuclear deal remains a concern, specifically because while Trump has staunchly opposed Obama’s deal, he has yet to offer “practical alternatives.”

“The future of the Iran deal, at this writing, remains uncertain,” the journal stated.

Finally, climate change and U.S. tensions with Russia are also noted as serious threats to the world.

In its recommendations, the journal urges the U.S. and Russia to “exercise restraint and professionalism” to avoid conflict, and encourages Americans to “demand climate action” from the Trump administration after its withdrawal from the Paris accord.