Credit: Kevin Walsh, CC BY 2.0.

The scientific movement to declare a new geological epoch called the Anthropocene has received a lot of attention in the popular press. There seems to be an impression that designating an Anthropocene Epoch is a cool or compelling way to recognize that human societies have caused recent and ongoing global climate change, as well as other systemwide impacts on Earth, including acidification of the oceans, widespread species endangerment and landscape changes. I have even heard it said that the idea of the Anthropocene is a way to acknowledge and begin facing our personal and collective responsibilities with respect to those impacts.

Although some may consider the idea a good way to name a set of real and very serious problems, embracing the Anthropocene as an inevitable new geologic epoch betrays a misunderstanding of its quite serious material and ethical implications, especially regarding our conceptions of, and relationships with, the natural world and other species.

Scientific interpretations of unprecedented evidence of anthropogenic activity in rock layers — as would be required to geologically define a new epoch — have serious implications and social ramifications, for they provide the evidence for our common ideas about Earth, and our ecological relationships. There are important differences between noticing a geological signal, and interpreting and defining that signal as the sign of a “new normal” that has fully supplanted the current Holocene Epoch. We need much more discussion about the ethical dimensions of the proposal that the Holocene Epoch has ended and has been permanently replaced by the Anthropocene, and as such, we ought to table the question of the existence of the Anthropocene.

What’s in a Name?

The idea of the Anthropocene was first introduced into the scientific literature in 2000 by Paul J. Crutzen and Eugene F. Stoermer in the International Geosphere-Biosphere Program’s Global Change Newsletter. Since then, interest has grown in a hypothesis that Earth is in a new stage, distinguished by particularly intense, long-lasting and harmful anthropogenic impacts, and that this new stage amounts to a new geological epoch. An epoch, by its geological definition, denotes a stretch of time “during which the rocks of the corresponding series were formed.” It implies an observable record in rocks that is distinct from the previous epoch. Thus, those who propose the Anthropocene as a new geologic epoch implicitly suggest that direct anthropogenic impacts are visible in the rock record in unprecedented, stratigraphically marked ways.

The Working Group on the Anthropocene (WGA), a committee appointed by the International Union of Geological Sciences (IUGS), describes the Anthropocene as an age uniquely marked by “many geologically significant conditions and processes profoundly altered by human activities.” WGA’s definition highlights changes to the biosphere as well as “erosion and sediment transport associated with a variety of anthropogenic processes, including colonization, agriculture, urbanization and global warming; the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements … and environmental conditions generated by these perturbations [including] global warming, ocean acidification and spreading oceanic dead zones.” The WGA notes that before the Anthropocene is officially accepted, the proposal has to be scientifically justified by observations of the stratigraphic record.

The definition provided by the WGA makes clear that, in every sense, the marks of the Anthropocene Epoch have been produced by phenomena — from widespread human colonization to species extinctions — that have caused and continue to cause catastrophic harm to humans and nonhumans alike. Debates about the events that ushered in the Anthropocene are also telling. Some suggest it dates to about 1800, around the start of the industrial revolution, which created countless benefits but also, ultimately, put us on a path to catastrophic climate change. Alternatively, members of the WGA propose that the beginning of the Anthropocene, and hence the end of the Holocene, occurred specifically with the explosion of the world’s first nuclear bomb on July 16, 1945, at Alamogordo, N.M.

Geographically, that event was chosen because it produced a clear and indelible mark on Earth in the form of “worldwide fallout easily identifiable in the chemostratigraphic record.” As we all know, it also produced clear, catastrophic and long-lasting harms.

In identifying the product of nuclear warfare as the characteristic mark of a new age for Earth, we risk encouraging a grand narrative that conceives of the human relationship with our surroundings and fellow species as inevitably and ultimately destructive, careless and selfish. Instead, we should regard the proposed demise of the mammal-friendly Holocene Epoch as a crisis in the extreme that we should work to avoid.

The Anthropocene hypothesis necessarily implies that the proposed new epoch has supplanted the Holocene, Earth’s current epoch, which began about 10,000 B.C., after the Pleistocene epoch and the end of the last major ice age. Geological epochs have previously ranged in duration from about 2 million to 23 million years, so if the Holocene has abruptly been terminated after only a dozen millennia by human action, it would certainly be a deviation from geologic history.

The ethical implications of embracing the idea that the Anthropocene has begun should not be taken lightly. “Holocene” may seem like just a name, but it designates particular ecosystems that have been studied and defined. Those systems are living contexts in which all human cultures have developed and evolved, and they include multitudes of species with their own inherent worth. From the perspective of any ethical system that values the natural world, the prospect of the death of the Holocene should be viewed as a catastrophe, for the WGA’s claim that “the Holocene has terminated” is a declaration that the human-friendly climates and ecosystems dominant over the last 12,000 years are beyond saving.

The possible end of the Holocene due to anthropogenic impacts is not an interesting opportunity; it is an absolute tragedy calling for unprecedented responses. Collectively, in geological time, we humans have only recently begun to comprehend the details of our impacts. And it was comparisons with particular previous states of ecological and human health that enabled biologists such as Rachel Carson and Barry Commoner to show that certain practices and industries had created unprecedented anthropogenic pollution. Those comparisons helped raise global consciousness, and provided the basis for laws, policies and practices designed to protect the environment.

Holocene conditions and species continue to provide the necessary common reference points for determining ecological health and for motivating environmental movements. If the Holocene is over, what provides a rationale for our responsibilities to restore and strengthen the species and ecological states identified with the Earth that human beings knew before the ravages of industrialism and pollution?

The Power Behind a Name

The intensity of anthropogenic impacts at all scales calls for efforts to preserve Holocene conditions, strengthen resiliencies and mitigate harmful anthropogenic impacts. In effect, advocates of the Anthropocene hypothesis argue that the current state of crisis should be officially designated Earth’s “new normal.” If the proposed Anthropocene Epoch is a set of realities distinctly characterized by colonization, chemical agriculture, global warming, nuclear warfare and “significant anthropogenic perturbations,” it is difficult to understand the apparent rush to define away the Holocene epoch.

Some may believe there is no great risk in declaring the Holocene over, thinking that scientific names and denominations are merely symbolic. That view to me seems both naive and inaccurate. Even in a climate where politically motivated skepticism and anti-science ranting seem rampant, science — in part through its classifications and definitions — has the power to shift common understanding and directly impact the world.

Because the power to define can be potent, it comes with significant ethical responsibility. For example, when the International Agency for Research on Cancer classified sunlight exposure and secondhand tobacco smoke as “carcinogenic to humans,” they inspired broad social changes, including new laws and policies with economic implications. More abstractly, geneticists who identified bonobos as our “close relatives” implicitly provided a compelling argument for protecting bonobo habitats, because there are ethical and pragmatic reasons to provide for the health of our close relations. Trust in science requires confidence that new definitions and proclamations are based on decisive evidence, for all of society may be left dealing with the policies and norms that follow in the wake of a weighty scientific proclamation.

The Anthropocene hypothesis centers on a claim about how to label the significance of the stratigraphic evidence of recent anthropogenic impacts on Earth and earth systems. Members of IUGS advocating for the Anthropocene hypothesis argue that the marks of recent systemscale impacts, such as worldwide nuclear fallout from July 1945, indicate that the planet has been propelled into a new geological phase. It seems equally accurate to regard the marks of recent anthropogenic development and disturbance at the global scale — including current climate change, mass species endangerment and pollution of the oceans — as a dangerous syndrome that has already left scars, and that urgently needs to be remedied.

A Premature Conclusion?

The idea of the Anthropocene threatens to enable the intensification of eco-destruction and inequity into the future. At this point, anthropogenic signals in the geologic record caused by industry, war and happenstance policies should be regarded as crucial lessons and urgent warning signs, rather than as conclusive evidence that the Holocene Earth has expired. Perilous environmental changes and compromised systems at planetary scales are trends that need to be reversed. It is impetuous to move directly from denial to fatalism, for in between there is the space where one can perhaps best address a problem. We’ve only just begun, but we have begun, to comprehend and respond to the environmental impacts of the recent century.

Instead of declaring the death of the Holocene, let’s interpret the lasting environmental traces of war, pollution and disruption as crucial warnings within the current epoch, encouraging ethical and empowering responses rather than pessimism, in science and beyond. Several centuries from now, let interpreters of our responses more accurately determine the fate of Holocene species and environments, with more thorough evidence and more realistic assessments of what we will be able to achieve in the next few generations.