Two threats could push humanity toward extinction by the end of the century: a nuclear war, leading to global famine, and the malicious use of artificial intelligence. These are the most extreme risks among the 17 identified by the Lancet Commission on Global Health Threats of the 21st Century, which reviewed hundreds of potential threats to assess their impact on human health between now and 2100.
The report, presented at the World Health Summit in Berlin, does not predict that these scenarios will occur; rather, it assesses their catastrophic potential and the possibilities for limiting the damage through targeted interventions. The Commission brings together 35 experts and examines a wide range of threats—from conflicts to chronic diseases—emphasizing how they are often interconnected and can exacerbate one another.
From nuclear war to the malicious use of AI
A nuclear conflict is one of the most extreme scenarios because the consequences of a large-scale war would extend far beyond the direct victims of the explosions. The destruction of crops and climate changes could lead to a global famine, threatening the survival of a huge portion of the population.
The other risk with the potential to lead to extinction concerns the intentionally harmful use of artificial intelligence. Among the concerns raised by experts is the possibility of using these systems to design biological weapons. The Commission, however , distinguishes between malicious use and the potential benefits of AI, which can also contribute to scientific research and health care.
The report does not assign a date to these scenarios nor does it claim that extinction is a likely outcome. The estimates pertain to risks characterized by a high degree of uncertainty and are intended primarily to identify areas where prevention can mitigate the effects of the worst-case scenarios.
The Other 15 Threats to Global Health
In addition to these two extreme risks, the Commission identifies 15 other threats: air pollution, antimicrobial resistance, child malnutrition, climate change, conventional conflicts, reductions in international health aid, high alcohol consumption, hypertension, income inequality, low levels of education, natural pandemics, obesity, mental health issues, smoking, and unhealthy aging.
To compare such diverse scenarios, experts use DALYs, which stands for Disability-Adjusted Life Years: the years of healthy life lost due to premature death or disability. The estimates cover the period from 2025 to 2100 and assess how much the burden on health could change when moving from worst-case scenarios to more favorable ones.
Among the most significant findings is the data on antimicrobial resistance—that is, the ability of bacteria and other microorganisms to resist the drugs used to combat them: targeted interventions could prevent 3.44 billion DALYs by 2100. With regard to income inequality, the gap between possible scenarios amounts to 13.8 billion healthy life years. Improving access to education, on the other hand, could prevent 16.1 billion DALYs.
The Health Costs of Global Warming
The Commission estimates that limiting global warming to 1.8 degrees, rather than allowing it to reach 4.4 degrees, could prevent the loss of 1.89 billion healthy life-years by 2100. The calculation takes into account already measurable harms, including those related to extreme heat and air pollution. It does not include all the effects that are more difficult to quantify, such as drought and the impact on mental health.
Another threat concerns the possible drastic reduction in international health aid. According to estimates reported by The Guardian, such a scenario could result in up to 1.5 billion DALYs by 2100, nearly 70% of which would occur in sub-Saharan Africa.
The Commission identifies three areas for action: strengthening the preparedness and resilience of health systems; supporting innovation by ensuring appropriate governance and equitable access to its benefits; and monitoring the evolution of risks over time. The proposals also include an observatory dedicated to global threats.
The experts’ message is that the extent of the damage will also depend on the decisions made today. As Christopher Murray, the commission’s chair, points out, “The decisions made today by our leaders will shape the health and well-being of the next generation.”
