Until 2100, humanity is likely to face a paradoxical situation: demographic decline and aging in some regions will be combined with growth and youth in others, and technology, especially artificial intelligence, will become the main driver of the economy. The key choice is between the scenarios of \"too little, too late\" and \"a giant leap\".

Demographics: peak passed, the world is aging

According to UN forecasts, the world's population will reach a peak of 10.3 billion around 2084, after which it will slowly decline, reaching approximately 10.2 billion by 2100. The main reason is the decline in fertility: in more than half of the countries in the world, the total fertility rate is below the replacement level (2.1 children per woman).

This will lead to a radical change in the population structure.

• Aging. The number of people over 65 will more than double — from 857 million today to 2.4 billion by 2100. Their share will grow from 10% to 24%. For the first time in history, the elderly and young people under 25 will be represented by approximately equal shares.
• Leadership change. China, whose population is expected to decline from 1.4 billion to 633 million, will be replaced by India. African countries (Nigeria, DR Congo, Ethiopia, Tanzania) will become the main drivers of global growth.
• Migration. To mitigate the effects of aging, developed countries will be forced to either stimulate fertility or actively attract immigrants. Studies show that with the complete cessation of immigration, the share of the United States in the world GDP could fall from 14.4% to 9.2% by 2100.

Technology: artificial intelligence as the foundation of the economy and war

By 2100, technology will become an integral part of the economy and security. Projections indicate that artificial intelligence and automation will determine global power.

Climate and resources: two forks

The future by 2100 will largely depend on how quickly the world will stop using fossil fuels. There are two fundamentally different paths.

• Scenario \"too little, too late\". With the continuation of current policies and slow reaction to climate challenges, the world is facing gradual disintegration: increasing inequality, social tension, degradation of democracy and ecosystems. Global warming could reach 3.2°C by 2100, leading to extreme weather events, droughts, and fires.
• Scenario \"a giant leap\". If humanity can implement five extraordinary reversals (fighting poverty, reducing inequality, expanding women's rights, transforming food and energy systems), there is a chance to keep warming within 2°C and create sustainable prosperity. This will require unprecedented levels of international cooperation.
• Resources and collapse. Some systemic dynamic models show that with the continuation of current trends, global economic growth may reach its peak and turn into a decline this century due to resource depletion and climate damage.
• Ocean currents. A separate concern is the risk of stopping the Atlantic Meridional Circulation after 2100 due to high emissions, which would cause a sharp cooling in Europe and changes in precipitation in the tropics.

Conclusion: an era of abundance or an era of decay

Projections for 2100 paint not a single picture, but a fork. Optimistic scenarios show that with an annual economic growth of 2.6% and large-scale investments in green energy, even the poorest layers of the population will be able to live at the level of today's Switzerland. The world will become economically 8.5 times larger, and the population will reach 12 billion.

However, without decisive political action, humanity risks sliding into a scenario of gradual decay, where technological progress and wealth will be distributed extremely unevenly against the backdrop of climate disasters.

Permanent link to this publication: