For at least 50 years, we have been living in the Anthropocene, although until recently, all of us Anthropos (human in Greek) were completely unaware of it. Of course, most people are not aware of our place in geological time, and the Anthropocene does not technically exist yet, but the scientific effort to define the beginning of the Anthropocene represents our effort to recognize when human activities have irreversibly altered the climate and ensured a global warming event that has already changed the direction of the planet’s evolution. Humans are a powerful climate forcing variable, but we have exercised that power in harmful ways. However, we still have a chance to choose to use our knowledge and power to change the direction of the planet’s evolution and create a future that supports climate equilibrium and ecosystem stability. Our choices will be recorded in the rocks that form on the planet’s surface, and our decisions will remain forever in the planetary record of Earth.
The history of the Earth is recorded in rocks, materials that form over thousands or millions of years as the planet’s outer layers change. OLLI Course In spring 2022, I will host a talk called “The Story of Earth as Told by Rocks,” where I will share 4.5 billion years of evidence of Earth’s evolution over the course of 12 hours. I looked at rocks and fossils that show important changes in the Earth system, such as the formation of the Moon, oxygenation of the atmosphere and oceans, the evolution of macroscopic life, the formation and destruction of supercontinents, and the role of large igneous provinces (just like massive volcanic eruptions) in mass extinctions that changed the course of life on Earth. 12 hours is not enough time to cover 4.54 billion years, and we could easily spend dozens of hours just focusing on a few hundred million years of Earth’s history. Much of the knowledge geologists have gained by observing the material and chemical changes Earth has experienced tells us that our current, anthropogenically caused climate predicament is comparable to devastating geological events that occurred millions of years ago. Because the rock record shows that rapid climate change events (RCCEs) and associated mass extinctions are not uncommon throughout geological time, we hope that we can use our knowledge of the past to prevent self-inflicted catastrophes. In fact, the geological time scale is primarily structured around mass extinction events.
There are approximately 10 GSSPs in North America, including the well-known “Golden Spikes” such as:
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Fortune Head, Newfoundland, Canada = The end of the Precambrian period, which includes about 8/9 of Earth’s history, and the beginning of the Phanerozoic/Paleozoic/Cambrian period, 538.8 million years ago, when the ancestors of the major lineages of skeletal animals began to appear in the fossil record.
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Greenpoint, Newfoundland, Canada – 485.4 million years ago, at the end of the Cambrian and beginning of the Ordovician, a key period Conodonts (a strange, creepy, and now extinct vertebrate) evolved in the sea
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Arrow Canyon, Nevada = End of the Mississippian Period and beginning of the Pennsylvanian Period 323.2 million years ago, when the earliest terrestrial tetrapods began laying eggs on land
The GSSP not only represents divisions on the geological time scale, but literally identifies geographic locations where scientific evidence of the evolution of life and changes in the planet’s climate is available. Earth’s history is a catalog of the evolution of the planet’s surface, life on the planet’s surface, and the ever-changing climate that determines where life can thrive and when it will become extinct. Our knowledge of climate change over 4.54 billion Earth years comes from rocks, which are records of changing surface conditions. The geological time scale is simply how we organize that information, and it continues to evolve as we get new information every day.
Until the Anthropocene came into being, we are living in the Holocene, the last division of the Cenozoic Era. The Cenozoic Era (meaning “recent life”) is divided into periods that span the past 66 million years. The term “cene” comes from the Latin “recens” meaning recent, new. “Holos” is Greek for whole, well-kept, or complete, so Holocene means “completely new.” The Holocene began 11,700 years ago, when the last ice age ended and natural warming processes began the interglacial period of the current glacial period in which we are currently living. During this interglacial period, which we call the Holocene, humans have transformed the Earth’s surface through agriculture, civilization, pollution, hunting, fishing, transporting invasive species, genetically modifying plants and animals, and a rapid increase in human population. This mark on the Earth in the past century has produced results comparable to devastating geological events that occurred millions of years ago that we know about through observations of the rock record.
In the early 2000s, the end of the Holocene The Anthropocene, the mid-20th century, is a time when traces of human activity are so deep they are recorded in rocks and remain forever as evidence of humanity’s impact on the planet. The golden spikes have not yet been officially selected, There are 12 potential sites, four of which are in North America, two of which are in California, one of which is in the San Francisco Estuary.This distinction is made because the San Francisco Bay ecosystem isCompletely transformed by introduced organisms“It is due to human activity. When geologists named the Holocene, they had no idea that the name “totally new” would describe such a massive change brought about on the Earth’s surface by a single species: Homo sapiens, aka “wise man”. The Anthropocene division reminds us that we have left our footprint on the Earth. At the moment, that footprint is not one we can be proud of, because it is the pollution and destruction of ecosystems that marks the beginning of the “totally human era”. But we can still change how we use the Earth’s resources. That footprint can evolve from destructive to supportive… if we choose to support the ecosystems we depend on, instead of taking what we want without regard for the impact on the Earth’s inhabitants. As individuals, we can be more careful about what we buy and how we dispose of our waste. And by supporting economic and political change towards a more sustainable future, but that choice is ultimately one that must be made by the Homo sapiens species as a whole…I wonder how wise our choices will be for the rest of the Anthropocene.
