The most severe population crashes in history have been caused by disease, and we are now much better at preventing and treating them.
At its peak, the Roman Empire was home to around 30% of the world’s population and was a leader in technological, legal, and economic progress. Its citizens enjoyed the benefits of central heating, concrete, double glazing, banking, international trade, and upward social mobility. Rome was the first city in history to reach one million inhabitants and was a center of innovation. It seemed an empire impossible to topple, stable and powerful. Until it wasn’t anymore. First slowly, then suddenly, the most powerful civilization on Earth collapsed.
Civilization, in this case meaning a complex society with specialized labor, social classes, and institutions, allows us to become efficient on a large scale, collect vast amounts of knowledge, and put human ingenuity and natural resources to work. It also allows us to construct impressive monuments, share a dominant language and culture, and domesticate plants and animals to feed and sustain large cities. Without it, most people would never have been born.
Collapse is the rule, not the exception. All civilizations end, on average after 340 years. This is rarely a pleasant experience for individuals, as their shared cultural identity is shattered and institutions lose the power to organize people. Knowledge is lost, living standards fall, violence increases, and often the population declines. The civilization either completely disappears, is absorbed by stronger neighbors, or something new emerges, sometimes with more primitive technology than before.
What about us today? Our cities stretch for thousands of square kilometers, we travel the skies, and our communication is instant. Industrial agriculture with engineered high yield plants, efficient machinery, and high potency fertilizer feeds billions of people. Modern medicine gives us the longest lifespan we’ve ever had, while industrial technology gives us an unprecedented level of comfort and abundance.
However, this modern, globalized civilization is even more vulnerable in some ways than past empires, because we are much more deeply interconnected. A collapse of the industrialized world would mean that the majority of people alive today would perish, since without industrial agriculture we would no longer be able to feed them. There is an even greater risk: what if a collapse were so deeply destructive that we were unable to re-industrialize again? What if it ruined our chances of enjoying a flourishing future as a multiplanetary species?
Let’s start with some good news. While civilization collapses have happened regularly, none have ever derailed the course of global civilization. The most severe population crashes in history have been caused by disease, and we are now much better at preventing and treating them. The internet is a huge repository of knowledge and the vast majority of it is stored on hard drives and servers. So even if the internet itself were to be destroyed, we’d still have a lot of information that could help us restart civilization.
No pandemic, no natural disaster, no war—the last clear example of a rapid global population decrease was the Black Death, a pandemic of the bubonic plague in the fourteenth century that spread across the Middle East and Europe and killed a third of all Europeans and about 1/10th of the global population. Despite the immense loss of human lives and suffering, European economic and technological development was not negatively impacted in the long run, as population size recovered within 2 centuries. History is full of incredible recoveries from horrible tragedies, such as the atomic bombing of Hiroshima during World War 2, where 140,000 people were killed and 90% of the city was at least partially incinerated or reduced to rubble, yet the population recovered within a decade and today it is a thriving city of 1.2 million people.
Today, humanity has unprecedented destructive power, with nuclear arsenals so powerful that an all-out global war could cause a nuclear winter and billions of deaths, and our knowledge of our own biology and how to manipulate it is getting so advanced that it is becoming possible to engineer viruses as contagious as the coronavirus and as deadly as ebola. Despite this, there are reasons to be optimistic that we could recover from a massive collapse. For example, there are 1 billion agricultural workers today, so even if the global population fell to just 80 million, it is virtually guaranteed that many survivors would know how to produce food. Additionally, the internet is a huge repository of knowledge stored on hard drives and servers, so even if the internet itself were to be destroyed, we’d still have a lot of information that could help us restart civilization. Finally, we should stop using easy-to-access coal, so it can serve as a civilization insurance in case something bad happens. We would certainly lose a lot of crucial institutional knowledge, especially on hard drives that nobody could read or operate anymore. But a lot of the technological, scientific, and cultural knowledge stored in the world’s 2.6 million libraries, would survive the catastrophe. The post-collapse survivors would know what used to be possible, and they could reverse engineer some of the tools and machines they’d find. In conclusion, despite the bleak prospect of catastrophic threats, natural or created by ourselves, there is reason for optimism: humankind is remarkably resilient, and even in the case of a global civilizational collapse, it seems likely that we would be able to recover – even if many people were to perish or suffer immense hardship, and even if we lost cultural and technological achievements in the process. But given the stakes, the risks are still unacceptably high. Nuclear war and dangerous pandemics threaten the amazing global civilization we have built. Humanity is like a teenager, speeding around blind corners, drunk, without a seat belt. The good news is that it is still early enough to prepare for and to mitigate these risks. We just need to actually do it.
We made this video together with Will MacAskill, a Professor of Philosophy at Oxford and one of the founders of the effective altruism movement, which is about doing the most good you can with your time and money. Will just published a new book called What We Owe The Future, which is about how YOU can positively impact the long-term future of our world. If you like Kurzgesagt videos, the chances are high you will like it! The book has some pretty counter intuitive arguments, like that risks from new technology, such as AI and synthetic biology, are at least as grave as those from climate change. Or that the world doesn’t contain too many people, but too few. And especially that everyday actions like recycling or refusing to fly just aren’t that big a deal compared to where you donate, or what career you pursue. Most importantly, it argues that, by acting wisely, YOU can help make tomorrow better than today. And how WE together can build a flourishing world for the thousands or millions of generations that will come after us.
Many things we at Kurzgesagt talk about regularly are discussed here, in much greater detail. Check out What We Owe The Future wherever you get your books or audiobooks. Did we manage to unlock a new fear for you? Let’s counter existential dread with appreciation for humanity. Look how far we’ve come as a species. What we’ve built and where we’ve gathered. Let this new World Map Poster be a reminder of what we can achieve.