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Geologist: The Anthropocene epoch is already underway. We will be left with concrete, microplastics and implants

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– Current climate changes will have repercussions for tens of thousands, or even hundreds of thousands of years – emphasizes geologist Jan Zalasiewicz, professor emeritus at the University of Leicester, who is one of the initiators of the concept of establishing an epoch called the Anthropocene. As he says, “we have changed biology in every corner of the Earth on an unprecedented scale and in an extremely short time.”

There is ongoing debate in the scientific world about whether the so-called Anthropocene, from the Greek word for human, has occurred. It would highlight the profound changes that have occurred on Earth as a result of human activity. International Union of Geological Sciences (IUGS) in March, she officially opposed the establishment of a new era in the history of humanity.

One of the promoters of this concept is geologist Jan Zalasiewicz, professor emeritus at the University of Leicester, who since 2009 headed the Working Group on the Anthropocene established by the International Commission on Stratigraphy (ICS). It is the largest scientific body of the International Union of Geological Sciences. In 2023, he was awarded the IG Nobel Prize for expertly explaining why some geologists lick rocks.

“All these changes leave traces”

According to prof. Zalasiewicz, establishing a new geological era is important “primarily because the world has changed so much.” – The oceans and atmosphere have a different chemical composition than a few decades ago. The increase in greenhouse gases in the atmosphere and global warming are a fact. The physical structure of the Earth is also changing under the influence of human activity. Thanks to us, much more sediment and rocks are moving on the planet's surface – argues the geologist. He adds that as humanity, “we also interfere with biology.” – On the one hand, many species are extinct, on the other hand we have homogenization of the biosphere caused by the transfer of plants and animals between different regions and continents – he explains.

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As professor points out Zalasiewicz, “all these changes leave geological traces.” – Sedimentary layers formed over the last 50 or 70 years are full of microplastics and synthetic radioisotopes. Current climate change will have repercussions for tens of thousands or even hundreds of thousands of years. Biological changes are permanent, he emphasizes. Therefore, in his opinion, “the Anthropocene has already arrived.”

As he argues, “there was too little discussion and the decision to reject the Anthropocene was not made based on evidence. Meanwhile, our Working Group on the Anthropocene has a lot of evidence.” – But the Anthropocene is a new idea and it also includes elements that geologists usually do not take into account. For example, concrete or plastics, according to many researchers, do not fit into the conservatively perceived geology, and human activity does not yet fit into geological time – he explains.

– I think we are dealing with a similar situation as before, when other new, radical ideas appeared. The theory of plate tectonics, or the hypothesis that a meteorite impact killed the dinosaurs 66 million years ago, was once highly controversial. Initially rejected by many conservative geologists, it took a long time to convince them. The Anthropocene is such a new idea that challenges many previous concepts. We knew there would be resistance to its formal acceptance – comments Prof. Zalasiewicz.

He emphasizes that the Anthropocene Working Group continues its work. – We may have to wait for a new generation of scientists who will not be so attached to the classical concepts of geology. However, for this concept to break through among geologists, a lot of time and work is still needed – he estimates.

Climate change and its consequences in the worldAdam Ziemienowicz, Maciej Zieliński/PAP

“Less than a hundred years ago there was a near-vertical peak.”

As the geologist admits, one of the reasons for the dispute related to the Anthropocene is its duration, which is only 70 years. – How can the time of one human life be an epoch? For me, the answer is obvious when we look at the graph of the pace of changes caused by humans, says the scientist. He points out that until recently there was only a horizontal line on it. – People appear on Earth, farm, build cities and empires, but the planet remains the same. However, less than a hundred years ago there was an almost vertical peak in the diagram – he points out.

– 66 million years ago, a meteorite hit the Earth in Mexico. The event took the blink of an eye, but it caused colossal changes to the planet. Millions of species became extinct, the domination of dinosaurs ended, and mammals began to develop. 70 years after the meteorite impact, the world was completely different. Now we are at a similar moment of change, we can no longer return to Holocene conditions – says Prof. Zalasiewicz.

Expert: in this respect we are unique

The scientist compares the impact of human activity to two significant events from the much more distant past. As he emphasizes, “there are two important differences.” – Firstly, a single species, Homo sapiens, is now responsible for great changes, and secondly, changes on Earth are taking place much faster. In this respect, we are unique in the history of the world, he notes.

As the scientist reminds, “2.5 billion years ago, a certain microorganism – probably a bacterium, or rather a group of various microorganisms – permanently transformed the Earth.” – He began using sunlight to convert carbon dioxide into oxygen and water. Photosynthesis caused the atmosphere to fill with oxygen. For the microbes of that time, oxygen was a toxic substance, so many of them died. Those that adapted survived, and then other oxygen-resistant organisms were created. This process took hundreds of millions of years, he describes.

– The next breakthrough probably occurred about 600 million years ago, when the first organisms capable of moving using muscles appeared. They could move around in their environment, swim, crawl or bury themselves in the ground. Animals disturbed sediment layers and caused physical and chemical changes on the Earth's surface. Later rocks are full of traces of these creatures. It was also not one species, but many groups of organisms – says the geologist.

Consequences of climate change in EuropeMałgorzata Latos, Adam Ziemienowicz/PAP

“We will leave behind a very clear fossil record.”

When asked what traces of people will remain in the settlements if someone were to examine them in millions of years, the specialist replies that “there will definitely be concrete and plastics in the layers corresponding to our era.” – Metal objects, such as cans, may retain their shape, but may also change into other compounds, for example, through oxidation or mineralization, they may turn into carbonates or sulphates. The glass will also remain, but will likely be opaque. It will tarnish over time like volcanic glaze. – There is no doubt that we will leave behind a very clear fossil record. Future geologists will have no problems finding traces of the Anthropocene – says Prof. Zalasiewicz. – Human bones and teeth may be preserved, but they will constitute a new type of fossil. About a hundred years ago, our skeletons began to change. Metal tooth fillings appeared, then hip prostheses and other implants made of plastic or metal, which remain almost intact despite the passage of time – he explains. As he adds, “we will also leave clothes behind. Modern archaeologists do not find many of them in the remains of centuries and thousands of years ago, because natural fabrics decompose quickly. But today we produce plastic materials, much more durable than cotton and wool.”

Climate risk rankingPAP/Adam Ziemienowicz

Prof. Zalasiewicz: we have changed biology in every corner of the Earth

As the geologist comments, “there is no doubt that the rate of extinction has increased markedly.” – Today it is estimated to be hundreds or thousands of times higher than the extinction background level known from the fossil record (the so-called extinction background is from 10 to 100 species per year). This is not the beginning of this process, our ancestors have already successfully wiped out mammoths and woolly rhinos from the face of the Earth – he says.

However, according to the researcher, “the most important geological signal of our impact on the planet” is not the extinction of species. – More importantly, we are responsible for moving countless species of animals and plants between continents and oceans. This phenomenon, which has intensified with international travel and global trade, is leading to the homogenization of ecosystems on our planet. – We have changed biology in every corner of the Earth on an unprecedented scale and in an extremely short time – he points out.

He adds that this process may contribute to the emergence of new species “provided that the catastrophic impact of humans does not wipe out all life from the Earth.” – The existence of each species that survives will be the starting point for a new type of life that will develop in the future – he explains.

– It is difficult to predict what life on Earth will look like in the future, and several interesting publications have even been published on this subject. We can imagine rats growing as big as elephants, or rabbits becoming as big as antelopes. You can speculate all you want, but no one has any idea what direction evolution will take. However, there is no doubt that changes are awaiting us in this matter, says Jan Zalasiewicz.

Climate change increases the risk of mass migration around the worldAdam Ziemienowicz/PAP

Main photo source: Shutterstock

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