Welcome to the Anthropocene

We live in the Anthropocene – the geological era shaped by humans. With this thesis, the Dutch chemist and Nobel Prize winner Paul J. Crutzen caused a sensation in 2000. The term is derived from the Greek word “anthropos” (human being). According to Crutzen’s assumption, which is corroborated by the US biologist Eugene F. Stoermer, the Anthropocene has taken over from the most recent geological epoch – the Holocene or post-glacial age. While nature was still omnipotent in the Holocene, the earth is influenced predominantly by humans in the Anthropocene. [1] Human legacies such as nuclear radiation, plastics, or concrete residues are deposited in the sediments.

Climate change supports the thesis that a new geological era has dawned

Crutzen’s theory has given rise to scientific debates. [2] Is it actually correct to proclaim a new geological era? No, says geologist Manfred Menning from the German Research Centre for Geosciences (GFZ) in Potsdam and chairman of the German Stratigraphic Commission (DSK) until 2015. In the geological context, the term Anthropocene “is of no use whatsoever” and therefore unnecessary, he told the business newspaper Handelsblatt. [3]

A contrary opinion is held by Reinhold Leinfelder, professor of palaeontology and geobiology at Freie Universität Berlin, member of the Anthropocene Working Group of the International Commission on Stratigraphy (ICS), and founding director of Futurium from 2014 to 2016, who argues in favour of the Anthropocene. Humankind is a force of nature, Leinfelder told the Neue Zürcher Zeitung, and this brings responsibilities with it. He argues for developing a new awareness of the impact of human actions: “It’s down to us whether the Anthropocene is going to lead to new struggles for resources, wars, and environmental catastrophes of unimaginable proportions, or lead us into a new era of sustainability and societal viability.” [4]

The date for the beginning of what is possibly a new geological era is contentious too. Scientists of the University College London and the University of Leeds want to prove with their study that the human era began with the conquest of America. [5] According to their theory, the widespread deaths among the native American population after the invasion by Europeans may have triggered the Little Ice Age, which lasted from the 16th century until the mid-19th century. Since agriculture hardly took place during this period, forests expanded and CO₂ emissions decreased – with temperatures dropping significantly. Other researchers claim that the Anthropocene began with the invention of the steam engine or the nuclear age.

The scientific community agrees that human intervention has been shaping the earth, especially since the middle of the 20th century. Many of the changes brought about by humans will still be visible millions of years from now. However, it is not too late to curb this development.

Five reasons why we are in the Anthropocene:

1. The earth is warming up – faster than ever before

Climate change is a sure sign that humans are interfering with processes on earth. Triggered by global warming, climate change has been speeding up more than ever before. It began with the industrial revolution: from 1850 to the present, the average global temperature has increased by about one degree Celsius. [6]

Global warming is caused by humans: since the middle of the 19th century, humans have increasingly burned fossil sources such as coal, oil and natural gas to produce energy and fuel. CO₂ is released in the process. If the amount of CO₂ in the atmosphere is too high, the earth heats up as if it were under a heat dome.

One of the consequences: around the globe, the weather is becoming more extreme, and in the long run our climate will change. Scientists predict that dry regions will suffer from a rising number of prolonged droughts, while water-rich areas will have to cope with increasingly heavy rainfall and flooding. Around the globe, this development has already been manifesting itself over the course of recent decades.

2. Global warming causes sea levels to rise

The earth is warming – and ocean temperatures are rising accordingly. All over the world, polar ice caps are melting, and glaciers and ice sheets shrinking. One analysis [7] shows how the melting Antarctic ice sheet has been causing sea levels to rise more than ever before in the past 25 years. With devastating consequences for oceans and coastal regions, which could be facing severe changes.

The current Special Report on the Ocean and Cryosphere in a Changing Climate [8] by the United Nations Intergovernmental Panel on Climate Change (IPCC) predicts: if we humans continue to produce gigantic amounts of greenhouse gases, sea levels are likely to rise by 0.61 to 1.10 metres by the end of the century. According to a recent US study [9], many more people than was previously assumed could become affected by rising sea levels. Benjamin Strauss, one of the authors of the studies, told Deutschlandfunk radio that 450 million coastal residents could be living below the flood line by the middle of the century. [10]

If this development becomes reality, many coastal regions will become uninhabitable over the course of this century. Another problem that could then arise for coastal residents is that the ground-water table would rise with the sea level. Soils would become waterlogged – and groundwater salty – as seawater seeped into reservoirs. In addition, entire ecosystems would become unbalanced because of the major changes for animals and plants in their coastal habitats – or entire habitats such as the Wadden Sea could disappear completely.

3. More and more species are becoming extinct

Humans are endangering biodiversity around the globe. Rainforests are being cut down, industry and agriculture are polluting waters and soils, massive fishing is threatening natural ecosystems. Climate change is also affecting biotopes – the region of a habitat associated with a particular ecological community – which are facing major changes. The World Biodiversity Council (IPBES) predicts a large-scale general extinction of species if the temperatures on earth continue to rise: one million species could die out over the next years and decades, according to the 2019 UN report. [11]

And there’s another indication that we are in the Anthropocene: millions of years from now, it will still be possible to prove that species have spread worldwide because of human impact. New species – for example the raccoon – settle outside their original habitats and displace other animals in their new ones. According to the World Wide Fund for Nature (WWF), in 2014, about 1,150 non-native animal species, and 12,000 non-native plant species, were counted in Germany alone. [12] More than 860 of these have firmly established themselves and are reducing the living space of native flora and fauna.

The marine habitat is changing too. Oceans store a large part of the heat generated by the human-induced greenhouse effect. In addition, they absorb from the aerosphere around one third of the carbon dioxide, which is generated primarily through the burning of fossil fuels [13]: the chemical reactions occurring in the process increase the concentration of carbon compounds in the water. As a result, the acidity of seawater increases slightly too (read more about this process here).

The “acidification” of the oceans is already endangering marine life such as the corals of Australia’s Great Barrier Reef. Their calcareous shells dissolve in the slightly acidic water, as do the calcareous skeletons of many animal plankton species. In the long term, they will cease to exist as a food source – and the entire marine ecosystem will suffer as a consequence. [14]

4. Human areas replace natural areas

Aerial photographs of the earth illustrate impressively how humans have interfered with natural landscapes. Scientists say it has become a geological factor. According to the US environmental scientist Erle C. Ellis, around 75 per cent of the inhabitable surface on earth has been shaped by humans – and has therefore been turned into so-called anthromes. [15] The term is composed of the Greek word “anthropogenic” (influenced by humans) and biome, the term used for habitats as they were previously known. Only just under a quarter of the earth’s surface is still covered by virgin nature.

A study published by the Science Journal [16] illustrates the creeping loss of wilderness: between 2001 and 2015, more than three million square kilometres of forest were cleared around the globe. That’s an area more than eight times the size of Germany. One quarter of this former forest landscape has been lost forever.

That’s because a large part of the forest areas has given way to urban agglomerations. Or it is used for agricultural purposes, to produce food for the ever-growing human population. As a result, the soil is increasingly being eroded by wind or water. Entire landscapes and biotopes have also been changed by river regulation in the form of straightened watercourses or dams. Quarries, mining tunnels, urban tunnel and pipe systems, as well as networks of roads have changed the earth’s surface forever – and left a human mark on it.

5. We live in the “technotope”

The entirety of things produced by humans and their machines – from smartphones to nuclear waste dumps – weighs in at an estimated 30 trillion tons. This is the conclusion of an international study [17]. According to calculations made by the team of researchers, this so-called technosphere pollutes our planet with 50 kilograms per square metre of the earth’s surface.

The scientists are convinced that many of the “technofossils” will be used in the future to date and characterise the Anthropocene. After all, new human-made materials such as concrete, fly ash or plastics will continue to bear witness to the Anthropocene as technofossils – for example as microparticles in the oceans – millions of years from now.

This is the case because, unlike most biological relics, many technofossils are non-degradable. They settle down and remain detectable as tiny particles in different geological layers. Radioactive dust from past and future nuclear tests will be detectable there too. For this reason, some researchers argue that the beginning of the Anthropocene should be marked by the first atomic bomb test on 16 July 1945.

What happens next?

But what’s going to happen next in the human era? Do we want to go on in the future as we are now, destroying the earth? How serious are we about taking responsibility for our planet? Scientists interpret the Anthropocene in very different ways and, against this backdrop, develop various strategies for dealing with the changes on earth in the future (read more about individual concepts here). Will the goal be to roll back wherever possible the impacts on landscapes that have already happened? Should technological interventions in nature be more greatly intensified for this purpose? Or should we primarily attempt to develop concepts that preserve the remaining natural landscapes and fight climate change? Regardless of what the Anthropocene will look like in the future, the message of the need to take responsibility for the preservation of our planet has been heard.

Sources and bibliography

[1]https://www.nature.com/articles/415023a

[2] http://www.klimaretter.info/forschung/hintergrund/18455-crutzen-qwir-brauchen-wieder-oekologieq
[3] https://www.handelsblatt.com/technik/forschung-innovation/anthropozaen-wann-begann-das-zeitalter-des-menschen-eigentlich/12837570-2.html?ticket=ST-29329672-HdsbD2dAq4h3poMdsart-ap5
[4] https://www.nzz.ch/wochenende/anthropozaen/wir-kommen-nicht-zurueck-ins-holozaen-ld.1509967
[5] https://www.sciencedirect.com/science/article/pii/S0277379118307261#!
[6] https://www.ncdc.noaa.gov/sotc/global/201908
[7] https://www.nature.com/articles/s41586-018-0179-y
[8] https://www.ipcc.ch/srocc/home/
[9] https://www.nature.com/articles/s41467-019-12808-z
[10] https://www.deutschlandfunk.de/steigender-meeresspiegel-viel-mehr-menschen-bedroht-als.676.de.html?dram:article_id=462262
[11] https://www.ufz.de/export/data/2/228053_IPBES-Factsheet_2-Auflage.pdf
[12]https://www.wwf.de/themen-projekte/biologische-vielfalt/invasive-arten-gefahren-der-biologischen-einwanderung/
[13] https://science.sciencemag.org/content/363/6432/1193
[14] https://www.br.de/klimawandel/ozeane-weltmeere-erwaermung-co2-klimawandel-100.html
[15] Cf. Ellis, E. C., Ramankutty, N.: Putting People in the Map: AnthropogenicBiomes of the World, in: Frontiers in Ecology and the Environment 6/2008, p.439–447, here p. 445.
[16] https://science.sciencemag.org/content/361/6407/1108
[17] https://journals.sagepub.com/doi/abs/10.1177/2053019616677743