From obesity to nuclear conflict and AI use: 17 threats that could shape humanity’s future, warns Lancet Commission

Humanity’s greatest health threats this century may not come from a single pandemic, war or environmental crisis, but from the combined effects of disease, climate change, inequality, technological risks and conflict.

A new Lancet Commission on 21st Century Global Threats to Health has identified 17 interconnected threats that could cause catastrophic losses to human health between 2025 and 2100. Launched at the World Health Summit 2026 in Berlin, the assessment argues that today's decisions by governments, industries, and international institutions will determine how much preventable illness, disability, and premature death future generations face.

Two threats stand apart-malicious use of AI and Nuclear conflict. The commission says they could cause human extinction.

The remaining 15 catastrophic threats include air pollution, antimicrobial resistance (AMR), childhood malnutrition, climate change, declining development assistance for health, conventional conflict, high alcohol use, high blood pressure, income inequality, low educational attainment, naturally occurring pandemics, obesity, poor mental health, smoking and unhealthy ageing.

The Commission classified a threat as catastrophic if it could account for at least one billion disability-adjusted life years (DALYs) by 2100, sufficient data existed to model its potential impact, and policy action was possible. DALYs measure years of healthy life lost through illness, disability or premature death.

The researchers said selection was based not only on the potential scale of harm but also on whether sufficient evidence existed to model the threat and whether policy interventions could reduce its impact. They also said major causes of ill health, including ischaemic heart disease and several site-specific cancers, were excluded from the catastrophic category because they already receive substantial policy attention and global health expenditure.

“Never before in human history have we been so clearly forewarned about the perils that await us if we heedlessly race ahead on the road to perdition. Again, never before in human history have we been so well forearmed with the knowledge and tools to forestall those dangers. It is a challenge to human intellect and enterprise to utilise those wisely to protect humanity and the planet,” says Dr K Srinath Reddy, public health expert and Founder President of the Public Health Foundation of India.

Nuclear conflict and AI among the gravest threats

The Commission examined hundreds of potential threats, drawing on historical evidence and health data covering 204 countries and territories. It identified two threats with the potential to cause human extinction by 2100: nuclear conflict, including nuclear famine, and the malicious use of artificial intelligence, including the development of biological weapons.

Although the probability of these events remains comparatively low, their potential consequences are exceptionally severe.

The Commission estimates that preventing nuclear conflict could avert 133 million deaths and 9.35 billion disability-adjusted life years (DALYs) by 2100. Reducing the risks associated with malicious AI could avert an estimated 10.4 billion DALYs.

DALYs measure the years of healthy life lost through illness, disability or premature death. They assess the health burden of different threats and estimate the potential benefits of interventions.

Why India cannot afford to ignore the warning

For India, the findings carry implications across public health, economic policy, environmental protection and national preparedness.

Obesity is a particular concern. The new Commission estimates that obesity could account for 23.1 billion DALYs globally by 2100 that could potentially be avoided through interventions. In 2022, India had the third-largest number of adults living with obesity worldwide, according to a global analysis published in The Lancet using the standard international body mass index threshold of 30 or higher. A separate Indian analysis using a lower BMI threshold of 25, , estimated that 254 million people had generalised obesity and 351 million had abdominal obesity in 2021.

For India, however, the implications reach beyond body weight management. Obesity is associated with increased risks of diabetes, cardiovascular disease and several cancers. Its growing burden makes prevention, early intervention and stronger health systems important priorities.

“India faces a mounting health crisis from rising obesity, hypertension, air pollution and deteriorating mental health, all contributing to preventable illness and premature mortality. Obesity fuels diabetes and cardiovascular diseases, while hypertension remains inadequately detected and controlled. Growing income inequality further widens disparities in access to healthcare and healthy living conditions,” says Dr Anoop Misra, eminent diabetologist,Executive Chairman of Fortis C-DOC Hospital for Diabetes and Allied Sciences.

“ A decline in Development Assistance for Health (DAH) could further weaken essential healthcare programmes, particularly in poorer countries. India urgently needs stronger preventive policies, early screening, environmental action and equitable healthcare. Failure to act now will impose an enormous health and economic burden on future generations,” he adds.

Climate change and inequality could exact a staggering toll.

Climate change is among the most far-reaching threats identified because it can worsen other risks. The Commission estimates that limiting global warming to around 1.8 degrees Celsius, rather than allowing it to reach 4.4 degrees, could prevent 1.89 billion years of healthy life from being lost to causes including extreme heat and air pollution.

The actual burden could be greater when harder-to-quantify consequences, such as displacement, drought and mental health impacts, are considered.

Income inequality could account for an estimated 13.8 billion DALYs by 2100, a burden the Commission compares with 25 COVID-19 pandemics. It also estimates that improvements inside educational attainment could avert 16.1 billion DALYs.

A shift from crisis response to prevention

An accompanying editorial in The Lancet describes the Commission’s work as “a radical conceptual shift” in how humanity thinks about future threats to survival. Instead of approaching each danger as a separate problem, it calls for a wider framework for coordinated action.

The Commission proposes three priorities: build readiness, back breakthroughs, and track threats.

Building readiness means strengthening health systems to anticipate, prevent, and respond to multiple risks, supported by sustained financing rather than emergency spending after a crisis begins.

Backing breakthroughs requires investing in innovations where existing solutions fall short, including vaccines, antibiotics, obesity treatments, and climate technologies, while guaranteeing fair access.

Tracking threats requires regular, independent assessments that incorporate new evidence and identify emerging dangers before they grow. The Commission proposes a Lancet Monitor of 21st Century Global Threats to Health to make this process more systematic.

India's way forward is to combine these risks and plan long-term strategies holistically.

The country must tackle obesity while confronting malnutrition, strengthen pandemic preparedness while dealing with AMR, and link environmental policy with public health, which will require cross-sector coordination.

The future, the Commission argues, is not predetermined. The question is whether governments can recognise how these threats interact and act early enough to prevent avoidable losses of life and health by the end of the century.