Nighttime comes after the end of daytime, and then the sun comes up from the east. A new day, another cycle. At a larger time scale, people all over the world observe season cycles in a year, with one season swiftly following the end of the previous. The end seems always to be followed by the beginning of something new, either as the beginning of the same cycle or creating a new one.
Do you wonder if there is something similar happening at an even larger time scale? Without being noticed by most people, the Earth itself is also experiencing cycles between glacial and interglacial periods. The current geological era we find ourselves in is called the Holocene, after the end of the last glacial period 11,500 years ago (Hoek & Bos, 2007).

The Anthropocene

So what exactly is the Anthropocene? As many of you may have heard before, this term has been used in different contexts and domains, from environmental research projects to art exhibitions in Berlin; it truly has become “a scientific and cultural zeitgeist, a charismatic mega-category form and encapsulating elements of the spirit of our age” especially since the atmospheric chemist and Nobel laureate Paul Crutzen popularized it in 2000 (Malhi, 2017; Stromberg, 2013). In this article, I would like to discuss it from an environmental and geological perspective.

Is the Anthropocene part of the cycles the Earth itself naturally experiences or is it a result of us putting an abrupt end to the previous epoch? Unfortunately, the answer may be the latter.
As as indicated by its etymology, anthropo- (from anthropos meaning “human” in Ancient Greek) and -cene (from kainos meaning “new” or “recent” in Ancient Greek) in its name, the term relates to human impact on the Earth system. Undoubtedly humans are exerting a great deal of influence on the Earth, in many ways outcompeting natural processes; for example the nitrogen cycle and the global climate are functioning beyond the Holocene envelope of variability. Therefore, scientists came up with the idea of Anthropocene indicating that the Earth may have left the Holocene and entered a new human-dominated geological epoch (Crutzen, 2002; Lewis & Maslin, 2015; Malhi, 2017; Steffen et al., 2015). Although it is apparent that humans’ impacts are huge compared to natural processes, Anthropocene is a relatively new concept which needs to be discussed thoroughly and developed further.

The Anthropocene itself, and when its onset began, are still under heated scientific debate. While some scientists criticized the idea because the clear-cut evidence for a new epoch was absent in the rock strata (Stromberg, 2013), recently, the Anthropocene Working Group of the International Commission on Stratigraphy have been working to decide when the Anthropocene began, with a focus around the mid-20th century;12 candidate sites are considered to mark the onset using lake samples from Crawford Lake in Canada to coral samples from Flinders Reef in Australia (Waters & Turner, 2022), which are likely to help scientists to determine the onset of Anthropocene.

End of an era

The end of the Holocene, or the onset of the Anthropocene, has some potential dates. There are theoretical guidelines to help determine the temporal boundary between two eras. Identifying the timepoint is often based on answering four questions (Smith & Zeder, 2013):

1. What degree of human modification and control of the environment is necessary to start the Anthropocene?
2. Over how much of the Earth’s land surface with the above human intervention needs to be documented to start the Anthropocene?
3. What kinds of information are appropriate and acceptable to use to start the Anthropocene?
4. To what extent should the established protocols and criteria used by the International Commission on Stratigraphy to define previous geologic boundaries be adhered to in establishing a lower boundary to the Anthropocene?

The attempted responses to these four questions resulted in different proposed dates, ranging from thousands of years ago to nearly present. Here are some examples:

One hypothesis suggests around 5000 years ago. Early extensive farming starting to impact the global environment because agriculture crops started to replace natural vegetation, speeding up species extinction and impacting biogeochemical cycles. The second hypothesis suggests 1610 AD. The collision of the Old and New World peoples took place and as a result, once distinct biotas especially in South America became homogenized. In the second hypothesis, the onset is defined by a pronounced dip in atmospheric carbon dioxide from an ice core, which can be attributed to the regeneration of the forest following a large decline in human numbers after Europeans arriving in South America. The third hypothesis suggests 1964 AD. This period was marked with the ‘Great Acceleration’ when population started to grow exponentially, and novel chemicals were produced in various industries. The onset in this hypothesis is marked with the peak in atmospheric radiocarbon from tree-rings and other records, and global temperature anomalies (Lewis & Maslin, 2015; Smith & Zeder, 2013).

The communality found across all three aforementioned example hypotheses, Homo sapiens, despite being just one species, play a major role in ending an era and shaping the emergence of a new one.

Why is this (end) important to you?

The potential end of the Holocene and the proposed start of the Anthropocene might sound like something only academics argue about at conferences. However, behind the labels is a much bigger story; humans have been gaining the power to moderate our mother planet, like a force no longer held in balance. For instance, the current extinction rate induced by humans is up to 700 times higher than the rate of nature itself (Christenhusz & Govaerts, 2025). It is something worth everyone’s attention, and the way in front of us remains largely unknown.