Limiting global warming to around 1.8 degrees Celsius, rather than allowing it to reach 4.4 degrees Celsius, could prevent the loss of 1.89 billion years of healthy life from causes including extreme heat and air pollution, according to a new Lancet Commission.
Researchers warned that the actual health burden could be even greater. Without steep emissions cuts, health losses would continue to accumulate beyond 2100 and could intensify other threats, including migration, in ways not captured by the current estimates.
The Lancet Commission on '21st Century Global Threats to Health' was launched at the World Health Summit 2026 in Berlin, Germany. Researchers assessed hundreds of potential threats and identified 17 that pose the greatest risks to human health and survival between 2025 and 2100. According to the authors, these threats can also be mitigated through policy changes, funding decisions, and innovation.
The 17 interconnected catastrophic threats span diseases, social and economic conditions, environmental change, technology and conflict, and are expected to shape the health of the next generation. If current trends persist, they could collectively account for tens of billions of years of lost health.
Every country faces significant risks, although the scale varies across threats and regions. Within countries, people with limited resources and marginalised communities are expected to bear the greatest burden, compounded by existing inequalities.
Nuclear conflict and the malicious use of Artificial Intelligence (AI) were identified as the two threats with the potential to cause human extinction, although their likelihood was assessed as low.
Considering both potential impact and probability, the commission estimated that action to prevent nuclear conflict could avert 133 million deaths and 9.35 billion years of healthy life lost by 2100. Measures to reduce the risk of malicious AI could prevent an estimated 10.4 billion years of healthy life lost.
“The estimates highlight how much health loss could be avoided in each area. Some are already imposing substantial health burdens today, while others carry a real danger if they materialise. Crucially, all 17 threats are interconnected, which is why they must be addressed together, not in isolation,” commission co-chair Christopher J L Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington, said.
“The striking finding is not only the scale of these threats, but that humanity still has the agency to act. Across all 17 catastrophic threats, the decisions made by leaders today will shape the health and wellbeing of the next generation. But delaying action will only serve to shift and increase the costs into the future,” Murray added.
The other threats identified by the commission are air pollution, antimicrobial resistance, childhood malnutrition, 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.
The commission also proposed a framework for taking action before harm becomes entrenched. Its recommendations include creating and funding health systems prepared to respond to threats, increasing investment in innovation, and regularly reassessing threats through independent reviews.