A new assessment of global health risks has identified 17 major threats facing humanity this century, with researchers urging governments to invest in prevention rather than wait for hazards to develop into emergencies.
The Lancet Commission on 21st Century Global Threats to Health brings together 35 experts. Its findings are due to be shared on Sunday at the World Health Summit in Berlin, and its assessment will be revised annually as evidence changes and new dangers emerge.
The report ranges from familiar causes of illness, including smoking and high blood pressure, to low-probability scenarios with potentially catastrophic consequences. Its central argument is that these problems interact and that addressing them together offers a more useful approach than treating each as an isolated crisis.
The most severe outcome is not a prediction
Nuclear conflict and the malicious use of artificial intelligence carry a risk of human extinction within the next 75 years, according to the assessment. The researchers describe the likelihood as low. They are not forecasting that either disaster will occur.
The nuclear scenario concerns famine caused when particles injected into the upper atmosphere block sunlight. The AI scenario includes the possibility of biological weapons created with advanced technology. Both are discussed because their potential consequences are exceptionally severe, not because the commission regards them as inevitable.
That distinction matters when interpreting the findings. A warning about an extreme possible outcome is different from an estimate that it is the most likely outcome. The commission's purpose is to identify opportunities to reduce risk before the harm occurs.
Counting years of healthy life
To compare threats, the researchers modelled disability-adjusted life years, commonly known as DALYs. This measure combines years lost through premature death with years lived in poorer health because of illness or disability.
The assessment classified threats capable of causing more than one billion cumulative DALYs by 2100 as major catastrophic threats. Inclusion also required potential solutions: the commission sought risks where realistic action could make a difference.
Alongside nuclear conflict and malicious AI use, the list includes air pollution, antimicrobial resistance, childhood malnutrition, climate breakdown, conventional war, declining overseas aid, heavy alcohol use, high blood pressure, income inequality, low educational attainment, naturally occurring pandemics, obesity, poor mental health, smoking and unhealthy ageing.
The breadth of that list challenges the idea that preparing for global health emergencies should be confined to outbreaks of infectious disease. Chronic illness, social conditions and policy decisions can produce a very large cumulative burden even without a single dramatic event.
Climate and aid decisions have measurable consequences
The commission compared scenarios in which global warming is limited to about 1.8C with one in which temperatures rise by 4.4C. It calculated that stronger mitigation could prevent 1.89 billion years of healthy life being lost.
These are modelled scenarios, not fixed outcomes. Their value is in showing the potential difference between choices made now and the long-term consequences of delaying action.
The report also examined reductions in international health aid, following large cuts announced by donor countries including the United States and Britain. A collapse or steep reduction in that aid could cost up to 1.5 billion DALYs before 2100, the commission found.
Nearly 70% of that projected loss would fall in sub-Saharan Africa, which also bears a disproportionate burden of childhood malnutrition. The figures underline how decisions taken in wealthier countries can affect health far beyond their borders.
Different regions face different burdens
Non-communicable conditions, including obesity and poor mental health, dominated the threats in higher-income regions. In lower-income regions, health losses were driven by factors including low educational attainment.
This variation means the report does not point to a single intervention suitable for every country. Strengthening health systems, investing in technological innovations and anticipating emerging hazards are among the approaches the authors advocate, with priorities informed by local circumstances.
Commission co-chair Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington, said the work began three years ago with conflict, climate and pandemics in mind. It revealed a much broader set of dangers requiring government attention.
The planned annual updates are intended to keep the assessment responsive to new data rather than preserve today's rankings indefinitely. The overriding message is not that catastrophe is certain, but that prevention, preparation and sustained institutional capacity can alter the health prospects of the next generation.
