At the beginning of Section 5.4, you engaged in a brief discussion about why some scientists say that we have entered a new geological time period, often called the human epoch or Anthropocene . Here, we return briefly to that discussion.
As you probably realized in your earlier discussion, the idea of a human epoch comes from thinking about what geologists living millions of years in the future might see in sedimentary strata from our time. There are many ways that they could learn about our lives today. For example:
- Because we have dug up (through mining) so many metals from the Earth and used them in our buildings and devices, the sedimentary layers from our time will have a much higher concentration of these metals than layers from before we built our civilization.
- The layers from our time will be the first to contain plastics, since plastics are human-made.
- Our layer will we marked by many more extinctions than layers under it, since we are driving many species to extinction.
- Careful study of the fossil record can allow geologists to learn about past climates, so future geologists may be able to find evidence of the global warming that humans are now causing.
The only question is whether these types of things will represent enough of a change in the fossil record to cause future geologists to say that this marks a new epoch. The answer is debatable, but this is one of those cases where the question is much more important than the answer.
Thinking about the way we might be viewed millions of years from now gives us a different way to think about ourselves in the here and now. In particular, we can all hope that it will cause us to think more clearly about whether we are acting in ways that will make it possible for our civilization to survive, so that there might indeed be geologists looking back at us from the distant future.
Discussion
The Human Epoch, Part 2
Use the following questions in small groups or as a class to revisit and build upon your discussion from the beginning of Section 5.4.
- Consider again what geologists living millions of years in the future might find in sedimentary layers dating to our time. Can you think of any other things (besides the four listed above) that they will find in “our” layer that they would not find in layers from before we built our modern civilization?
- Overall, do you think that future geologists will see enough change in the fossil record from our time to say that we are now living in a new “human epoch”? Why or why not?
- The text above says that this is a case in which the question (as posed above) is more important than the answer. Briefly discuss what this means, and why you think the question is important.
We encourage you to spend a little time on this discussion, because even though this is one of the shortest sections in the entire book, the topic is very important to the way we think about our future. Encourage students to take the idea seriously, and keep in mind that this idea will be worth revisiting as we discuss human impacts on our planet in Chapters 7 and 8.
Journal Entry
New Perspectives
In earlier chapters you have considered how learning about Earth’s place in the universe changes your perspective on our planet, our species, and on you personally. Now, consider what you have learned in this chapter about how Earth works and about geological time. Write a few paragraphs about how these ideas change your perspective. You may focus your writing on any aspects of perspective that you wish. For example, you might consider how learning the evidence for continental motion and plate tectonics affects your perspective on science, or on how learning about the human impacts of geology change your perspective on the way we live as a society, or on how the long time scales involved change the way you view humanity or yourself.