Will our species still exist in a thousand years? Humans have been pootling around on this planet for a tiny slice of its existence, so it stands to reason that at some point in the future, it will be game over for our descendants.
If our time is up long before 3022, then it would be reasonable to assume that the world would not look so very different from today. The atmosphere would be cleaner, of course, in the absence of fossil fuels being burned. The landscape would be a lot greener too, with forests, flowers and weeds reclaiming cities and towns—nature takes back its territory once people disperse or disappear. You only need to look at Tikal in Guatemala or Angkor in Cambodia, whose hundreds of thousands of inhabitants a thousand years ago would have listened in disbelief if you had told them that their cities would be filled with ghosts and tourists today. Back then they were vast metropolises at the centre of complex networks of exchange and teeming with cultural, political and military ambition.
Those cities and states fell into decline and their populations dispersed, partly because of changing climates: changes in rainfall patterns that included droughts that lasted for decades did not result in civilisational collapse—but they did add to existing pressures that made life more difficult, exacerbated rivalries, incentivised violence and reduced agricultural production. This time it is different. Such is the current rate of climate change that scientists are increasingly talking about a “sixth mass extinction”: plunging biodiversity, linked both to human exploitation of the landscape and to anthropogenic global warming, has seen a “cascading erosion” of all kinds of flora and fauna. It is startling in both scale and speed. Some animals and plants do well when others fail; that humans might fall into the former category seems doubtful.
For one thing, according to some studies, climate pressures are already “baked in”, meaning that significant warming would take place even if all emissions were halted with immediate effect. That means that we are in for sea-level rises of 11 and perhaps as many as 30 inches even if the Paris Agreement goals that were adopted in 2015 are met, and exposure to dangerous heat levels will increase by 50-100% across much of the tropics. Some are highly pessimistic about the future: one new study put the chances of limiting global average temperature change to the Paris targets at 0.1%. It seems all but inevitable then that populations will be pushed northward and southward, away from the tropics. Long-range modelling suggests that the Amazon may become a barren landscape by 2500, as temperatures continue to increase and sea levels rise by tens of metres, covering large parts of the world as we know it.
Warming is not distributed evenly around the world, and the burden will fall most heavily on the poor in low-income countries in tropical regions. The projections of what is coming towards us are chilling, with this year showing all too well what is at stake: temperatures rose above 40°C in Britain; China recorded the most severe heatwave anywhere on Earth; floods hit Pakistan with nearly 800% more rainfall than normal, affecting tens of millions of people and leaving a third of the country under water; winter temperatures in the southern hemisphere rose above 45°C in South America while temperatures in some parts of Antarctica were almost 40°C higher than average; and flash floods hit Death Valley in America, where three-quarters of a year’s average rainfall fell in just three hours. If and how we adapt will be the question of the 21st century, with the answers shaping the next millennium.
There are reasons to be optimistic that we can make it. For one thing, some new technologies might stem the damage we do to the natural environment. For another, plunging birth rates, particularly in high- and middle-income countries, means that there will be fewer of us in the future. That will ease pressure on finite resources, as well as on those that could be renewable—as long as consumption patterns do not continue to rise. This is significant given that natural resources are being expended today at a rate which means they are not being replaced. As one recent report put it, humanity currently require 1.6 Earths to maintain today’s living standards. That may change if populations fall sharply all around the world in the centuries ahead, and we all become more efficient with what we use and how we use it.
Even if the Scylla of climate change is avoided, the Charybdis of natural and other man-made disasters might sweep most of us away. Few need reminding that the prospect of military confrontation is alive and well. Even if resolutions can be found for Ukraine, Taiwan and other potential flashpoints in the coming years, it would be brave to bet against the use of nuclear weapons in a global conflict over the coming centuries. Instead the question would be how great an impact it would have—and whether it might affect the survival of our species. New climate models show that even a limited use of nuclear weapons would inject so much soot into the atmosphere that many regions would become unsuitable for agriculture for many years—and that is before factoring in escalation, which would produce a full nuclear winter and challenge human life on earth to its limits.
Consider the prospect of changing disease environments, too, which may make the covid-19 pandemic look like a cake-walk. One estimate suggests that the changing climate will leave 90% of the world’s population at risk of malaria and dengue fever by the end of this century. Although health systems in the Global North tend to be better, the recent coronavirus pandemic showed how sudden surges in demand for treatment can have dramatic impacts on primary health-care facilities, on medical staff and on equipment. Around 60% of infectious diseases are aggravated by climate hazards such as floods, droughts or shifts in marine environments. Humans must also contend with the rising resistance to antibiotics, which will result in tens of millions of deaths by 2100 and perhaps many more afterwards—unless new medicines or technologies are found.
Those of our descendants who make it past these climatic and biological milestones will find themselves living in a completely different world—one where artificial intelligence, machine learning, flying cars, bases on Mars, genetically enhanced babies and other products of science-fiction wishful thinking are less interesting and important than basic questions of survival. How many—if any—of us will be around to see it is a good question. At the rate we’ve been going, though, the world might be just as quiet as Tikal and Angkor are today—minus the tourists.
Peter Frankopan is Professor of Global History at Oxford University. He is the author of the forthcoming book Climate: A Lost History (Bloomsbury, 2023).