PHOENIX, ARIZONA — John Mecklin, editor in chief of the Bulletin of the Atomic Scientists, is retiring after 15 years in the role. The Bulletin focuses on global existential threats, including nuclear weapons, climate change, and disruptive technologies.

The Bulletin was founded in 1945, with Eugene Rabinowitch serving as its first editor. The organization maintains the Doomsday Clock, which was set at 85 seconds to midnight in January 2026. This setting marks the closest the Doomsday Clock has ever been to midnight.

The Bulletin reports nine countries currently possess nuclear weapons: the U.S., Russia, the U.K., France, China, Pakistan, India, and North Korea, and all nine are expanding and upgrading their arsenals. The combined nuclear arsenals of these countries contain approximately 12,187 warheads. International nuclear nonproliferation treaties are expiring or being abandoned, and China has not joined international nuclear arms control treaties.

The U.S. and Russia have terminated bilateral treaties that previously constrained their nuclear arsenals, resulting in no current treaty-based constraints on their nuclear arsenals. "After all that effort to end that extremely costly and senseless arms race during the Cold War, we're right back in the middle of it." Mecklin said. The International Campaign to Abolish Nuclear Weapons reported that nine nuclear-armed countries spent a combined $119 billion on nuclear weapons in the previous year, with the U.S. spending $69 billion, which exceeded the combined spending of the other eight nuclear-armed nations.

The Bulletin began reporting on climate change as an existential threat in the late 1950s, publishing its first cover story on the topic in 1978. In 2007, the organization formally added climate change and biotechnology to its scope of coverage. Today, its coverage also includes disruptive technologies such as artificial intelligence, nanotechnology, and biological technologies.

No independent assessment of John Mecklin’s claims was available.