Nuclear War and Rogue AI Could End Humanity by 2100, Lancet Warns—But Obesity May Cost the Most Healthy Years

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A new Lancet Commission has identified 17 interconnected catastrophic threats to human health through 2100, warning that nuclear conflict and malicious use of artificial intelligence are the only two with potential to cause human extinction. Yet the largest avoidable health burden may come not from a dramatic catastrophe, but from obesity, which could cost humanity 23.1 billion years of healthy life by century’s end.

What the report found

The Commission on 21st Century Global Threats to Health, launched at the World Health Summit in Berlin, analyzed risks across 204 countries and territories using Global Burden of Disease data. It measured potential harm in disability-adjusted life years (DALYs)—each representing one year of healthy life lost to illness, disability, or premature death.

A threat qualified as “catastrophic” if it could cause at least 1 billion DALYs by 2100, could be modeled with existing data, and offered a realistic route for policy action. The 17 threats span disease, economic and social conditions, environmental change, technology, and conflict.

The extinction risks

Only two threats were classified as having extinction potential: nuclear conflict and malicious AI. The report estimates that preventing nuclear war could avert about 133 million deaths, while reducing malicious AI risk could prevent roughly 10.4 billion years of healthy life lost by 2100—a burden comparable to naturally occurring pandemics and obesity.

The Commission examined three pathways through which AI could cause catastrophic harm: enabling biological weapons development, system failures such as autonomous weapons, and loss of human control over advanced systems. Forecasters consulted by the Commission showed wide disagreement on how likely an AI catastrophe actually is.

Obesity leads the avoidable burden

Despite the headline-grabbing extinction risks, obesity carries the single largest avoidable health cost on the list. If current trends continue, obesity could account for 23.1 billion DALYs by 2100—all potentially preventable through policies that reduce obesity risk.

Data cited in the report show overweight and obesity are rising in every country, with projections suggesting the global adult rate could hit 60% and a third of children by 2050 if nothing changes.

The full list of 17 threats

Beyond the two extinction-level risks, the Commission flagged: air pollution, antimicrobial resistance, childhood malnutrition, climate change, conventional conflict, declining development assistance for health, high alcohol use, high blood pressure, income inequality, low educational attainment, naturally occurring pandemics, obesity, poor mental health, smoking, and unhealthy ageing.

Low educational attainment—especially in sub-Saharan Africa—could cost 16.1 billion healthy years, while income inequality could cost 13.8 billion. Limiting global warming to about 1.8°C instead of 4.4°C could avert 1.89 billion lost healthy years.

A three-part action plan

The Commission’s roadmap rests on three pillars: build readiness through threat-ready health systems with dedicated foresight and prevention capacity; back breakthroughs via funding and innovation; and keep tracking threats through ongoing monitoring.

Co-chair Dr. Christopher Murray, director of the University of Washington’s Institute for Health Metrics and Evaluation, stressed that the heaviest burden will fall on resource-limited and marginalized communities, and that global health will be profoundly shaped by economic growth in sub-Saharan Africa, particularly the Sahel.

“The striking finding is not only the scale of these threats, but that humanity still has the agency to act,” Murray said, adding that because events like nuclear war and AI catastrophe have no historical precedent, “these estimates carry much greater uncertainty than those for other threats.”

Why it matters now

The report’s central message is that these 17 threats interact and amplify one another, meaning governments cannot afford to focus on a short list of favorites. Lancet editor-in-chief Richard Horton noted the goal is not to rank threats but to “catalyse international, regional, and national actions to protect and strengthen the future of health and humanity.”

Co-chair Dr. Natalia Kanem, former head of the UN Population Fund, put it bluntly: “Recent global events show us just how quickly stability can give way to crisis, and how costly it is to respond only after disaster strikes. Yet the future is not inevitable.”

The findings were released ahead of the World Health Summit in Berlin, which opened Sunday, with Murray leading a virtual media workshop on the findings on October 12.