What will be left of humanity in a million years?

Cities will collapse, computers will stop working, and most books will disappear. But a thin layer of concrete, plastic, metals, chicken bones, and chemical changes may tell future researchers that an industrial civilization briefly existed here that transformed an entire planet.

Suppose humans were to disappear tomorrow. It doesn't matter for the sake of this matter whether the cause was a natural disaster, a plague, a war, or a gradual process that would take thousands of years. What would someone digging in the Earth find in a million years?

The pyramids, skyscrapers, and dams seem to us today as monumental creations destined to last forever. But in geological terms, they too are temporary structures. Water will penetrate concrete, steel will rust, plants will break down roads, and temperature changes will crumble walls. Rivers will change their course, seas will rise and fall, glaciers will carve the land, and plate tectonics will continue to recycle the Earth’s surface.

In a million years, it is doubtful that an entire city will stand on a mound. Still, we will not disappear without leaving a trace. Instead of an intact tower, car, or telephone, future researchers may find an unusual geological layer containing a mixture that has no parallel in previous eras: concrete fragments, plastic particles, industrial compounds, metal alloys, ash from burning fossil fuels, and billions of bones from animals that humans raised for food.

This may be the signature of human civilization: not one magnificent monument, but a thin, global, and strange layer within the rocks of the future.

During the preparation of the article, the Haydan website spoke with Prof. Ron Milo of the Weizmann Institute of Science, who was a partner in a study that compared the mass of material created by humans with the living biomass on Earth. His words add to the discussion about the distant future a clear fact from the present: Today, it is not just about the footprints we leave behind, but about the amount of material that is comparable to and even exceeds the living world.

The mass we have created is already greater than the living biomass.

In 2020, Emily Elhachem, Liad Ben-Uri, Jonathan Grozovsky, Yinon Bar-On, and Prof. Ron Milo published Research in the journal Nature, who attempted to compare two enormous quantities: the biomass of all living things on Earth and the mass of materials that humans have produced.

The researchers included in the anthropogenic mass buildings, roads, machinery and products made of concrete, minerals, bricks, asphalt, metals, glass and plastic. They did not include waste generated after the use of these materials.

According to their calculations, at the beginning of the 20th century, man-made mass was equal to only about three percent of the global biomass. Since then, it has grown rapidly, while the mass of vegetation has declined significantly due to deforestation and land-use changes.

The researchers estimated that around 2020, with an uncertainty range of about six years in each direction, man-made mass would have reached about 1.1 trillion tons—the order of magnitude of all dry biomass on Earth. According to the study, humanity had produced, on average, more than the body weight of each person in roads, buildings, and products every week in the years leading up to its publication.

In a conversation with the Haydan website in late August 2026, Milo said that this point of equilibrium is already behind us. “Around 2020, the weight of anthropogenic mass equaled the weight of all living biomass on Earth,” he explained. When asked to assess the current situation, he emphasized that he did not have a new, precise measurement, but estimated that the mass of man-made matter is now about 20–30 percent greater than the living biomass.

This is an estimate based on the continuation of the trend measured in the study. He says that anthropogenic mass doubles about every 20 years. The coronavirus pandemic has caused some changes, but the overall rate of production remains, he estimates, roughly similar to projections.

Milo also emphasized what the comparison does not say. It does not compare human buildings to the entire mass of the Earth. Rocks, oceans, and non-living matter are much heavier. It is a “mass balance” between two defined components: all living matter on the one hand, and the materials that humans have produced on the other.

Anthropogenic mass and the technosphere are not the same thing

The discussion on the subject sometimes uses two concepts that sound similar but do not measure the same thing.

Anthropogenic mass, or anthropogenic mass, is the narrow definition: materials that humans have actually created, including concrete, bricks, asphalt, glass, wrought metals, cars, and telephones.

Technosphere is a broader definition. It can also include soil and rock that humans have moved or altered through agriculture, mining, excavation, and infrastructure construction, as well as waste and other systems related to human activity.

Therefore, there is no contradiction between the study by Milo and his colleagues, which estimated the anthropogenic mass at about 1.1 trillion tons around 2020, and A study that estimated the mass of the technosphere About 30 trillion tons. Each study focused on a different group of materials.

This does not mean that all of this mass will survive a million years. Much of it will decay, melt, oxidize, or be recycled through geological processes. However, the sheer quantity and global distribution greatly increase the chance that some of the materials will be buried in conditions that will allow their preservation or at least the preservation of their chemical imprint.

Not smartphones, but technological fossils

Geologist Jan Zalasiewicz and his colleagues proposed calling the human-made remains that could be preserved in future strata "Technological fossils" — technofossils.

Don't expect to find a smartphone in a million years that continues to display the images stored on it. The battery will break down, the circuits will oxidize, the glass will crack, and most magnetic or electronic information will be lost in a much shorter time. Paper, film, photographs, and digital drives are also very fragile ways of transmitting information over geological time.

But parts of the device may leave traces. Glass, ceramics, copper, gold, silicon, alloys and synthetic materials may be preserved as particles, as new compounds or as cavities and patterns within sedimentary rocks. A future researcher will have difficulty reconstructing the operation of the phone from them, but he will be able to recognize that this is a combination of materials that is not the product of a normal natural process.

Variety is as important as quantity. Civilization produces a vast number of objects of different shapes and compositions, and at a rate of change much faster than the rate of emergence of new species in evolution. A bottle, a ballpoint pen, a computer chip, and a car tire are in this sense different "species" within the world of man-made objects.

Earth of concrete

Skyscrapers themselves probably won't survive, but the concrete they're built from may be one of our most recognizable landmarks.

Concrete wears away and cracks, and the iron inside it rusts and widens the cracks. Nevertheless, large amounts of concrete debris will be buried in sediment, especially in cities located in estuaries, in floodplains, and along beaches that will be flooded.

Over time, the concrete may undergo chemical changes and become part of new rock. Instead of a complete wall, the geologist will find a layer rich in crushed building materials, glass grains, iron oxides, and minerals formed within the voids left by buildings and objects.

Cities that sink or are flooded may be better preserved than those located on mountains and in dry, exposed areas. Rapid burial in mud and sediment protects the remains from further weathering. Therefore, it is possible that neighborhoods, ports, and dumps that were swallowed by the sea or in river mouths will provide the most detailed archive of our lives.

Most of the land surface that exists today will not be preserved. It will be eroded or exposed again and again. The geological record is always partial: even dinosaurs survived only a few specimens out of a vast number of animals that lived for some 165 million years. But humanity has spread its products almost everywhere—from the oceans to the peaks of mountains—so it is likely that at least some of them will be buried and preserved.

What will happen to the plastic?

Plastic has become a symbol of the durability of human waste, but the statement that it “never decomposes” is inaccurate. Sunlight, oxygen, heat, waves, and biological activity break down polymers, turning large objects into tiny particles. Over long periods of time, their chemical composition may also change.

However, breaking down into particles is not disappearance. Microplastics are already found in soil, oceans, ice, and sediments. Particles that are buried quickly, away from light and oxygen, may be preserved for a long time. Others will leave behind unusual carbon compounds, molds, or minerals that have formed in their place.

New rocks containing plastic have already been found on several beaches. Sometimes it is plastic that has melted and bonded to sand, shells, coral or rocks following a fire. It is not certain that these structures will survive a million years in their current form, but they demonstrate how synthetic material is beginning to be incorporated into the rock cycle.

Even if the original polymer disappears, the layer in which it accumulated may remain very different from the layers above and below it.

Chickens may outlive humans

If future researchers look for a fossil that represents our era, it may not be a human but a domestic chicken.

Milo cautioned in the conversation that he is not an expert on all the processes that determine which materials will survive a million years. However, he mentioned that geological periods are often identified through bones, so the chicken bones may be a particularly clear marker of our era.

"For example, it would be possible to identify our era, that of humans and humanity now, based on the bones of chickens," he said. The chickens that humans raise for food have undergone extensive selection and improvement, and are therefore larger and different from the wild chickens from which they evolved. In addition, they are raised and eaten in enormous quantities.

According to Milo's comparison, the biomass of chickens in human households is about four times greater than the combined biomass of all 10,000–11,000 wild bird species in the world. Their bones accumulate in landfills and waste sites around the world, and the combination of quantity, distribution, and anatomical structure shaped by artificial selection may clearly distinguish them from bones from ancient times.

Article published in Royal Society Open Science suggested that the modern broiler chicken may in the future serve as a clear biological marker of the change that humanity has wrought in the biosphere.

The bones of cattle and pigs, pollen from agricultural plants, and the rapid disappearance of other species will also appear in the record. The future researcher will discover a biosphere that has undergone reorganization: a small number of domesticated species have become very common, while many natural habitats and species have shrunk or disappeared.

Signs that cannot be seen with the naked eye

Humanity's most enduring imprint may not be an artifact but a chemical change.

The burning of coal, oil, and gas has released into the atmosphere, in a geologically short time, vast quantities of carbon that had been buried for millions of years. Carbon from fossil fuels has a characteristic isotopic composition. Its release into the atmosphere, oceans, and sediments creates a perceptible shift in the layers.

Global warming, ocean acidification, species extinctions, and the global spread of species that humans have transported between continents may also leave long-term marks. A future researcher will be able to see that in a short period of time the composition of life has changed, the carbon and nitrogen cycles have changed, and an unprecedented amount of new materials have been created.

Nuclear tests in the atmosphere have left radioactive isotopes around the world, including plutonium-239. In layers formed since the mid-twentieth century, this is a clear time marker. However, even this marker is not eternal: the half-life of plutonium-239 is about 24 thousand years, so after a million years there will be a very small amount of it left. Over long geological timescales, it will also be necessary to identify decay products and other changes left behind by the nuclear age.

And what will be left in space?

Earth is a poor place for long-term preservation. It has water, oxygen, life, weathering, volcanism, and plate tectonics. In space, and especially on the moon, the conditions are different.

Most low-orbit satellites will lose altitude and burn up in the atmosphere within years, decades, or centuries, depending on their orbit. Even high orbits are not stable forever. Collisions, radiation, and the gravitational effects of the Earth, Moon, and Sun will gradually change them.

In contrast, the objects left on the moon’s surface—spacecraft parts, scientific instruments, and Apollo mission vehicles—are not exposed to rain, wind, or plate tectonics. Micrometeorite impacts, radiation, and temperature changes will gradually break them down, but they may last much longer than most structures on Earth.

The clearest evidence of human civilization may ultimately be found not where it was born, but on a dead celestial body nearby.

A tangible number for a huge responsibility

Milo says comparing masses is not just a statistical exercise. Climate crisis, he says, is sometimes difficult to grasp because it deals with a vast global system and changes measured in tenths of a degree, parts per million, and energy scales. Weight, on the other hand, is a more intuitive concept.

The fact that one species has created a mass that exceeds the total living biomass in a short time illustrates, he said, how much the relationship between humanity and the environment has changed. "We are one species on Earth, and we are already key players in shaping the biosphere — essentially our life-supporting environment," he said.

In the past, humanity was largely influenced by natural systems. Today, it also shapes them with unprecedented power. This, according to Milo, brings with it a “great responsibility” for the choices we make regarding the types of energy we use, the food we eat, and the methods we build.

Man-made mass is not a direct measure of greenhouse gas emissions or biodiversity loss. But it does provide a tangible measure of the depth of human intervention. If the matter we have created already outweighs all living matter by tens of percent, it is difficult to see civilization as a small, marginal factor in a large natural system.

A thin but global layer

In 2024, the authoritative bodies of geology rejected the proposal to recognize the Anthropocene as an official geological epoch that began in the mid-20th century. The decision does not eliminate the influence of humans. The dispute concerned the question of whether it was correct to define a new official epoch and at what point in time it should begin.

Even without official status, the term Anthropocene continues to be used to describe the era in which the activities of a single species have become a force influencing Earth's systems.

From a million-year perspective, our entire recorded history—from the first cities to the Space Age—would seem like a brief flash. Even a layer that lasted thousands of years would be very thin compared to layers that took millions of years to form.

But it will not be quiet. It will contain the sudden appearance of new materials, a sharp change in the carbon cycle, mass extinctions and migrations of species, the remains of cities, mines and drilling, billions of bones of farm animals and signs that one species has learned to break down the Earth's crust and assemble an artificial world from it.

Future researchers may not know our names, our languages, or the stories we told ourselves. They won't be able to operate our phones or read most of the books we've written. But they will know we were here.

They will also show that we have managed to change the Earth in an incredibly short period of time. What the layer alone will not reveal is whether we understood the significance of the change in time—and whether we were able to use our power to mitigate the damage before we disappeared.

Questions and Answers

Will buildings and cities remain intact in a million years?

Almost certainly not. Water, oxygen, vegetation, temperature changes, erosion, and geological movements will break down most structures. However, cities that are quickly buried under mud or sediment may leave behind layers of concrete, glass, metals, and voids in the shape of the original structures.

What is the difference between anthropogenic mass and the technosphere?

Anthropogenic mass is the mass of materials that humans have created, such as concrete, asphalt, glass, cars, and telephones. The technosphere is a broader concept that can also include displaced soil and rock, mines, waste, and infrastructure. Studies using these two terms may therefore arrive at very different figures without contradicting each other.

Why might chicken bones be a typical fossil of our time?

Humans raise tens of billions of broiler chickens, which have undergone artificial selection and are different from their wild ancestors. According to Ron Milo, their biomass is about four times greater than that of all wild bird species combined. Bones with an unusual structure, accumulating in huge quantities around the world, may be a clear marker of our times.

Is the Anthropocene an official geological epoch?

No. The proposal to officially recognize it as a period that began in the mid-twentieth century was rejected in 2024. However, the term continues to be used in science and public discourse to describe humanity's profound impact on the Earth.

More on the subject on the science website

• What geological imprint will we leave behind?
• Earth of concrete: Man-made mass equals the mass of the animal world
• Census of life on Earth: Trees still rule
• Can the human race avoid extinction?
• The Anthropogenic Period and the Human Imprint on the Israeli Landscape

For the scientific article: Opening the scientific article