Narrative
Description of Climate Change Records of the last 800,000 years Poster
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The only thing you can ever really count on is change. That is certainly true of Earth’s climate system. The climate of Earth has changed from one defined by an atmosphere without oxygen, over 2.5 billion years ago, to one where human activities are affecting the change. Earth’s history is marked by the evolution of organisms dependent on the state of the climate to eek out an existence or adapt as climate continued to change. We, as humans, are still on that path and must make accommodations to mitigate or adapt to the changing climate. Before we can decide how to proceed forward we must understand the details of the past. In the last century, scientists have developed techniques for interpreting Earth’s natural records as one would read a book, with each page or layer of rock revealing hidden mysteries of Earth’s past. Some of these techniques now allow us to read closely enough to interpret changes on time scales as short as individual years. When trying to understand paleo or ancient climate change there are a number of natural records that are being used as proxies for understanding the conditions present on Earth in the past. The paleo record goes back over one million years before the present (ybp) though the most detailed records extend to approximately 800,000 years before the present (ybp). Four of the commonly used methods for interpreting Earth’s climate are presented on the accompanying classroom sized poster. They are the recent modern instrumental weather data, and three proxy records obtained by precisely interpreting natural records. The length of time that each of these four records extends into Earth’s past differs greatly and is displayed on the poster. The instrumental record extends back into time over 120 years before present, the pollen record extends back 60,000 years before present, and the ice core and deep sea sediment records extend back to 800,000 years before present. Great care and precision by scientists have been used to obtain and analyze these important records. These data also geographically span the globe from pollen extracted from lake sediments in the United States to ice cores from Antarctica. Our hope is that this poster will serve as an effective educational tool to introduce students to the basics of Earth’s climate records. For further investigation, the poster has an accompanying, always evolving, web site where detailed information about climate change, climate records, appropriate classroom activities, images, animations, professional development opportunities, references, and links to numerous other fantastic sources of information on climate change are available.
Poster design and execution by Zach Smith, Scott Battaion and Nick Deamer, Wright Center for Science Education, Tufts University.