How much do we have to fear from A.I., really? It’s a question I’ve been asking experts since the debut of ChatGPT in late 2022.

The A.I. pioneer Yoshua Bengio, a computer science professor at the Université de Montréal, is the most-cited researcher alive, in any discipline. When I spoke with him in 2024, Dr. Bengio told me that he had trouble sleeping while thinking of the future. Specifically, he was worried that an A.I. would engineer a lethal pathogen — some sort of super-coronavirus — to eliminate humanity. “I don’t think there’s anything close in terms of the scale of danger,” he said.

Contrast Dr. Bengio’s view with that of his frequent collaborator Yann LeCun, who heads A.I. research at Mark Zuckerberg’s Meta. Like Dr. Bengio, Dr. LeCun is one of the world’s most-cited scientists. He thinks that A.I. will usher in a new era of prosperity and that discussions of existential risk are ridiculous. “You can think of A.I. as an amplifier of human intelligence,” he said in 2023.

When nuclear fission was discovered in the late 1930s, physicists concluded within months that it could be used to build a bomb. Epidemiologists agree on the potential for a pandemic, and astrophysicists agree on the risk of an asteroid strike. But no such consensus exists regarding the dangers of A.I., even after a decade of vigorous debate. How do we react when half the field can’t agree on what risks are real?

One answer is to look at the data. After the launch of GPT-5 in August, some thought that A.I. had hit a plateau. Expert analysis suggests this isn’t true. GPT-5 can do things no other A.I. can do. It can hack into a web server. It can design novel forms of life. It can even build its own A.I. (albeit a much simpler one) from scratch.

For a decade, the debate over A.I. risk has been mired in theoreticals. Pessimistic literature like Eliezer Yudkowsky and Nate Soares’s best-selling book, “If Anyone Builds It, Everyone Dies,” relies on philosophy and sensationalist fables to make its points. But we don’t need fables; today there is a vanguard of professionals who research what A.I. is actually capable of. Three years after the launch of ChatGPT, these evaluators have produced a large body of evidence. Unfortunately, this evidence is as scary as anything in the doomerist imagination.