A 27-year-old British researcher who worked on pretraining at Anthropic has publicly resigned, warning that the race to build recursive self-improving AI could lead to human extinction before the decade is out.
Jacob Coxon walked away from one of the most prominent AI safety companies in the world around September 8-9, and his parting message was not a polite LinkedIn post about “exciting new chapters.” It was a warning that the people building these systems genuinely believe they could produce catastrophic outcomes, and that the timeline for things spiraling out of control could be as soon as next year.
The insider alarm
What makes Coxon’s resignation particularly difficult to dismiss is what happened next. His own colleagues at Anthropic started publicly agreeing with him.
Evan Hubinger, who holds the title of Alignment Science Lead at Anthropic, backed up Coxon’s claims on social media. His personal estimate: a greater than 10% chance of AI leading to massive human fatalities within the next decade.
Hubinger went further, acknowledging that Anthropic lacks a clear plan for ensuring alignment with superintelligent systems.
Samuel Marks, another Anthropic researcher, echoed similar concerns, suggesting that senior employees inside the company are particularly worried about extinction-level risks.
Coxon specifically criticized the use of terms like “crunchtime” and “endgame” within AI development circles. These words frame the pursuit of superintelligence as something urgent and inevitable, a competition to be won rather than a risk to be managed. That framing, he argued, is part of the problem.
A pattern of exits
Coxon isn’t the first safety-focused researcher to leave Anthropic with concerns about the company’s direction. Mrinank Sharma, who led the company’s Safeguards Research team, resigned in February 2026. Sharma pointed to escalating dangers posed by AI and bioweapons, citing external pressures that he said were compromising the company’s ethical conduct.
The irony is thick. Anthropic was founded by former OpenAI staff, including CEO Dario Amodei, specifically because they felt OpenAI wasn’t taking safety seriously enough. It was supposed to be the safety-first alternative. Now its own safety researchers are leaving because they don’t think Anthropic is taking safety seriously enough.
Competition as accelerant
Coxon’s warning specifically flagged international competition as a factor making things worse. The pressure to keep pace with rivals, particularly from Chinese AI labs, creates an environment where slowing down to get safety right feels like unilateral disarmament.