“Mass extinction” has an intimidating sound to it. What does it entail, and is it something that we should be worried about? The answer to this is no… but also yes. Similar to many other threats to the environment and atmosphere, it is something we should pay attention to even though it will not necessarily affect us in this lifetime. To squash a common misconception, a mass extinction is not when half the population suddenly drops dead. A mass extinction is simply when species are decreasing at a faster rate than they are created, occurring typically every twenty-six billion years. Although this is a problem we should face far in the future, there are subtle signs telling us this may be occurring sooner than anticipated. Dwindling ecosystems are becoming so inhabitable that many diverse species are having to look elsewhere for a home.
These unfortunate outcomes are becoming more and more realistic, and in tandem, more of a cause for concern to those who study mass extinction. Notable authors like Elizabeth Kolbert have published articles and a Pultizer Prize winning book, The Sixth Mass Extinction, to bring the public’s attention to this approaching issue. Zalasiewicz et al. claimed that if extinctions continue at their current rate, the overall magnitude would match that of past mass extinctions.
Mass extinctions are characterized by some “catastrophic event” that creates a significant decline in species diversity. The most popular example of this would be the asteroid that wiped out the dinosaurs at the Cretaceous-Tertiary extinction about 66 million years ago, the fifth and most recent mass extinction. A large event such as this is displayed in the earth’s layers, forever recorded in geological time. This is observed in an area of study known as stratigraphy– the study of the earth’s layers. The large cosmogenous impact of the asteroid contained a substantial amount of the element iridium, which was found by stratigraphers.
Stratigraphy can detect any atmospheric, ocean, glacial, and sedimentary changes. Ocean acidification has been seen in the earth’s layers contributing to a few of the mass extinctions such as the end-Permian and end-Triassic. Our current epoch, unofficially named the Anthropocene, constitutes a new period of time defined by the influence of humans on the environment. The Anthropocene, stratigraphically, can be defined through spiking atmospheric carbon dioxide, industrial chemicals such as metals and plastics, and radionuclide fallout from weapons testing (Lewis & Maslin).
Ecological and atmospheric changes happening today are similar to the observable patterns that lead up to past mass extinctions. Elizabeth Kolbert is a well-renowned writer who covers a variety of environmental topics in her work. Her book, The Sixth Extinction: An Unnatural History highlights the ways in which our modern world is showing points of concern – many in comparison to past events – for mass extinction.
Species go extinct more often than we may think, according to Kolbert. This is especially true if you consider that we have only discovered a small portion of all the species on earth. But what happens if an entire ecosystem is destroyed, a forest clear cut, or a river dammed? Something as catastrophic as this has detrimental effects on countless species that call that land home and rely on it for protection. Unfortunately, this is the case for coral reefs.
Coral reefs create an ecosystem for a diverse array of marine species. This vast and intricate underwater forest, home to thousands of marine species, is disappearing before our eyes. Much of the increased carbon dioxide that has been added to the atmosphere is because of human activities related to fossil fuels, industrialization, and deforestation. The result of such action is an acidifying ocean, making it difficult for marine species to survive. To try and put the amount of carbon emissions in comparison: the overwhelming volcanic activity that contributed to the end-Permian extinction that lasted for two million years, emitted carbon at half the rate that we currently are (Cui, et al). This exemplifies what could come as a result of our emissions at the rate they are currently proceeding.
According to Kolbert, today, the ocean has risen in acidity and made life for marine calcifiers awfully strenuous, which is reflective of the third mass extinction 252 million years ago, the end-Permian extinction. Crabs, mussels, oysters, barnacles, and – you guessed it – coral are a few examples of marine organisms known as calcifiers. These species are reliant on building calcium carbonate shells — an increasingly difficult task with rising ocean acidification. Kolbert emphasizes that coral reefs could easily be our era’s first fully extinct ecosystem.
History, nature, and the Earth’s biosphere all go through patterns of repetition. While most people might hear this and think: “Earth has gone through this before, so what’s the harm if it happens again?” They fail to recognize just how different it is this time. The world has never had “us” before. Our impact on the Earth’s natural environment is something that has never before been seen. While our ecosystems continue to grow and change, they are doing so at a rate incomparable to any past events. This explains the proposed new era titled the “Anthropocene” where anthropo- means human and -cene means new. Establishing a defined era in which human impact on the planet has become substantial is one of the first steps to understanding how much of an impact we actually have.
Kolbert writes “Warming today is taking place at least ten times faster than it did at the end of the last glaciation […] To keep up, organisms will have to migrate, or otherwise adapt, at least ten times more quickly.” There has never been a “mass extinction” with factors like climate change or ocean acidification occurring at a rate similar to today’s. While this may seem impossible to solve, there are improvements and advancements we can make to combat this looming threat.
Phrases such as “The solution to pollution is dilution” are becoming more common, and are a great introduction to help people recognize the effects of their simple habits. Political solutions such as the Paris Accords have brought international activism to climate change. In addition, humans are capable innovators. While we may have innovated our way into this situation, there are many potential solutions to innovate our way out. For example, the utilization of certain renewable resources is a great way to lessen fossil fuel emission. Author Christina Figueres encourages a positive attitude towards the climate emergency. She emphasizes it is important to realize all the things we can do, rather than the potential downfall if we don’t change.
Adamson, J., Gleason, W. A., Pellow, D. N., Zalasiewics, J., Williams, M., & Waters, C. N. “Anthropocene.” Keywords for Environmental Studies, eds. Joni Adamson, William A. Gleason, and David Pellow, New York, New York University Press, 2016, pp. 14-16.
Kolbert, E. (2015). The Sixth Extinction: An Unnatural History. Henry Holt.
Lewis, S. L., & Maslin, M. A. (2015, March 11). Defining the Anthropocene. Nature News. Retrieved March 23, 2022, from https://www.nature.com/articles/nature14258