Archaeologists from around the world reveal deeper and more widespread roots of human age, the Anthropocene

Examples of how human societies are changing the planet abound – building roads and houses, clearing forests for agriculture and digging railway tunnels, shrinking the ozone layer, making species disappear, change the climate and acidify the oceans. Human impacts are everywhere. Our societies have changed the Earth so much that it is impossible to reverse many of these effects.

Some researchers believe that these changes are so important that they mark the beginning of a new "human age" in Earth's history, the Anthropocene epoch. A committee of geologists proposed to mark the beginning of the Anthropocene in the mid-twentieth century, on the basis of a striking indicator: the widely dispersed radioactive dust resulting from the nuclear bomb tests of the early 1950s.

But this is not the last word.

Not everyone is certain that today's industrialized and globalized societies will be long enough to define a new geological epoch. We are perhaps only a flash in the panorama – an event – rather than a long and lasting era.

Others debate the utility of choosing a single thin line in the geological record of the Earth to mark the beginning of human impacts in the geological record. Perhaps the Anthropocene began at different times in different parts of the world. For example, early examples of agriculture have emerged in different places and at different times and have had a considerable impact on the environment: clearing, habitat loss, extinctions, erosion and carbon emissions, permanently changing the global climate .

If the beginnings are multiple, scientists must answer more complex questions – as when did agriculture begin to transform landscapes in different parts of the world? This is a difficult question because archaeologists tend to focus their research on a limited number of sites and regions and prioritize sites where it is thought that agriculture has emerged more early. To date, it is almost impossible for archaeologists to develop a comprehensive picture of land use changes over time.

Global responses from local experts

To answer these questions, we have brought together archaeologists, anthropologists and geographers as part of a scientific research aimed at analyzing archaeological knowledge about land use across the planet.

We have asked more than 1,300 archaeologists from around the world to share their knowledge of how ancient peoples used the land in 146 regions covering all continents, with the exception of Antarctica, 10,000 years until 1850. More than 250 responded, representing the largest project of crowdsourcing expertise in archeology ever made. companies, although some earlier projects have worked with amateur contributions.

Our work has now mapped the current state of archaeological land-use knowledge across the planet, including parts of the world that have rarely been considered in previous studies.

We used a crowdsourcing approach because scholarly publications do not always include the original data needed to allow for global comparisons. Even when these data are shared by archaeologists, they use many different formats from one project to the next, making it difficult to combine for a large scale analysis. From the beginning, our goal was to allow everyone to control our work and reuse our data – we put all our research documents online where they can be freely consulted.

Previous and more generalized human impacts

Although our study collected archaeological information from experts all over the planet, data was more available in some regions – including Southwest Asia, Europe, northern China , Australia and North America – only in others. This is probably due to the fact that more archaeologists have worked in these areas than elsewhere, such as parts of Africa, South East Asia and South America. .

Our archaeologists have indicated that nearly half (42%) of our regions had a form of agriculture 6,000 years ago, which highlights the prevalence of agricultural economies around the world. In addition, these results indicate that the beginning of agriculture was earlier and more extensive than is suggested by the most common reconstruction in the history of land use in the world. history of the global environment. This is important because climatologists often use this database of past conditions to estimate future climate change; according to our research, we may underestimate the climatic effects associated with land use.

Our survey also revealed that hunting and foraging were usually replaced by pastoralism (raising animals such as cows and sheep for food and other resources) and farming in most places, with a few exceptions. Turnovers took place in some areas and agriculture did not simply replace foraging, it merged with it and coexisted side by side for a while.

The deep roots of the Anthropocene

The global archaeological data show that the human transformation of environments began at different times in different regions and accelerated with the emergence of agriculture. Nevertheless, 3000 years ago, most of the planet was already transformed by hunter-gatherers, farmers and pastoralists.

To guide this planet towards a better future, we must understand how we got there. The message of archeology is clear. It took thousands of years for the virgin planet of long ago to become the human planet of today.

And there is no way to fully understand this human planet without relying on the expertise of archaeologists, anthropologists, sociologists and other human scientists. To build a science of Earth more robust to the Anthropocene, the human sciences must play a role as central as the natural sciences.

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