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The Future of Humanity: When Will the Last Human Be Born and How Many Will Ever Live?

Author: Kurzgesagt – In a NutshellTime: 2024-01-04 15:50:00

Table of Contents

A Brief History of Human Population Growth

The human population remained small and stable for most of our existence, with gradual improvements in technology and survival leading to a population of around 2 million after 150,000 years. It was the agricultural revolution around 12,000 years ago that truly ignited population growth, allowing the number of humans to reach 300 million over the next 10,000 years.

This growth was then massively accelerated by the industrial revolution starting in the 1800s. In just the past 200 years the population has ballooned from 1 billion to over 8 billion today. About 7% of all humans ever born are alive right now, as many as were born in the first 150,000 years of human history.

From Hunter-Gatherers to Agricultural Revolution

For over 95% of human history, we lived as small bands of hunter-gatherers with limited ability to store food surpluses. Life expectancy was low, mortality rates were high, and population growth was gradual. The introduction of agriculture fundamentally changed this, allowing for systematic large-scale food production and storage for the first time.

The Effects of the Industrial Revolution

The industrial revolution, starting in the 1800s, brought about rapid advances in science, technology, and quality of life. This allowed death rates to plunge even as birth rates remained high, spurring massive population growth over a short period of time relative to previous human history.

Current and Projected Human Population

Today there are around 270 babies born every minute, totaling about 125 million births per year. The UN projects this rate to continue until around 2100 when the global population will peak between 10 and 12.5 billion people before starting to decline.

There is significant uncertainty in these projections however. Depending on whether humans colonize other planets or not, spread throughout the galaxy, avoid extinction events, and how long we survive as a species, potential future population numbers vary enormously.

Scenarios for the Future of Humanity

Given the uncertainties involved, we can consider different scenarios for the future of humanity and estimate potential total future population sizes.

If humans never expand beyond Earth, even conservative estimates point to around 100 trillion future humans given expected mammalian species lifespan. More optimistic estimates allowing 500 million years of habitability on Earth raise this number to over one quadrillion future humans.

Expanding beyond Earth allows populations orders of magnitude higher depending on the extent of space colonization. Spreading throughout the solar system could allow sextillions or more. Colonizing portions of the Milky Way galaxy could allow populations as high as 10^29. Leaving our galaxy potentially allows higher still.

If Humans Never Leave Earth

Conservative Projections

A conservative projection assumes humans survive about 1 million more years on Earth with stable birth rates, similar to average mammalian species longevity. This would mean around 100 trillion total future humans.

Optimistic Projections

More optimistic estimates based on Earth's potential 500 million year habitability raise projections to over 1.2 quadrillion future humans even with constant birth rates.

If Humans Become an Interplanetary Species

Becoming an interplanetary civilization utilizing resources from across the solar system could support populations many orders of magnitude higher than Earth alone, perhaps allowing sextillions of lives to be lived.

If Humans Colonize the Stars

If humans manage to colonize portions of the Milky Way galaxy over 10+ billion years, utilizing even a fraction of the star systems and energy available, projections climb to upwards of 10^29 potential lives.

Conclusion and Perspective for the Future

What becomes clear from these thought experiments is that if humanity avoids premature extinction, almost all human life exists in the future no matter how conservative the projections.

Rather than existing at the end of the human story, we are perhaps only 0.008% into the beginning. Quadrillions of potential people await being born, underscoring the immense responsibility we have today to steward the future.

Our choices matter enormously not just for those alive now, but for the unborn generations that deeply depend on our actions. With this perspective and sufficiently long timelines, perhaps we can build not just a good world, but an incredible one.


Q: How many humans have ever lived?
A: About 117 billion humans have been born and lived over the last 200,000 years.

Q: What percentage of all humans ever are alive right now?
A: About 7% of all humans that ever lived are alive right now.

Q: How many more humans could be born if we never leave Earth?
A: Conservative estimates suggest 100 trillion more humans could be born if we survive 1 million more years on Earth.

Q: What is the potential human population if we colonize the solar system?
A: Colonizing the solar system could allow orders of magnitude more people to exist, likely quadrillions.

Q: What is the potential human population if we colonize the galaxy?
A: Settling 100 billion stars for 10 billion years could allow hundreds of octillion more lives to be lived.

Q: Why does humanity's long-term future matter?
A: Quadrillions of potential future humans depend on the actions we take today for their chance to exist.

Q: When could the last human potentially be born?
A: If we survive and continue expanding for millions or billions of years, the last human birth could be extremely far in the future.

Q: How can we create the best future for humanity?
A: By sustaining progress, mitigating existential risks, expanding civilization, and ensuring future generations can thrive.

Q: What is the goal of the Kurzgesagt multi-language expansion?
A: To bring scientific knowledge and optimism for humanity's future to more global audiences by professionally translating videos.

Q: How can I support Kurzgesagt's mission?
A: Help spread the word about newly launched Arabic, Portuguese, French, Hindi, Japanese and Korean Kurzgesagt channels!