What Constitutes an Earth History Approach?

An Earth history approach focuses on the development of the Earth over time. At the simplest extreme, it's simply a litany of what happened, who did it, and when at a geologic scale. The stories include:

• "Why are the Applachian Mountains are so much smaller than the Rocky Mountains?"
• "How did Earth end up with an oxygen-rich, carbon-dioxide-poor atmosphere unlike her sister planets Mars and Venus?"
• "Why do trees on the east and west coasts of the US often belong to the same genus but different species?"
At the university level, if not earlier, instructors will want to focus on patterns and causes of change as well as on the events and actors themselves.

An Earth history approach allows instructors to:


• Engage our students by telling stories of bygone worlds teeming with strange creatures (not just dinosaurs!)
• Emphasize the ideas of time and change
• More effectively teach some of the most important ideas in modern science: evolution, plate tectonics, and climate change
Historical geology is an obvious course to teach with an Earth history approach, but it turns up in our classes in all kinds of contexts, from physical geology, to introductory biology, to global warming seminars, because it is a valuable tool for teaching the major ideas of science and a number of important skill groups, such as taxonomy and stratigraphy. All kinds of science courses can use one or more Earth history units and integrate them with the more usual descriptions of modern processes.


For example, my Earth system science course for teachers uses an Earth history approach even outside of the historical-geology unit. The other units are:


• The Ice Ages: mostly focusing on the Late Wisconsinan and how the ice age ended
• Volcanism: using the recent and carefully observed eruptions of Mount Saint Helens, Mt. Pinatubo and Mt. Kilauea
• Global Warming: using the IPCC report and the Keeling data
These three units give students perspectives on different causes of climate change working on different timescales, that we pull together at the end of the course, using data on both the past and the present.