TEACHING ABOUT CLIMATE CYCLES: A NEW COMPREHENSIVE STUDENT-ACTIVE LEARNING MODULE FROM ′BUILDING CORE KNOWLEDGE′ FOR THE UNDERGRADUATE CLASSROOM

As part of the NSF-funded CCLI Phase 1 project “Building Core Knowledge and Reconstructing Earth History”, this new three-part student-active learning module focuses on cyclic climate change in the geologic record, and the explanation of that change using astronomical theory. In Part 1 students examine records from a variety of archives, locations, proxies, and geologic epochs that display cyclic climate change. Students calculate the periodicities of these records, and reflect on sources and implications of scientific uncertainty. In Part 2 students first consider seasonality to draw out prior knowledge and misconceptions, and then examine the long-term orbital variations of eccentricity, obliquity, and precession. Students connect these orbital drivers to the periodicities in the climate proxy records in Part 1. In Part 3 students dissect the CO₂ record of the last 400 ky to characterize greenhouse gas levels during past glacial-interglacial periods and today. Students should identify a distinct break in the cyclicity and develop hypotheses to explain this change in climate.

The exercise set is designed for use in introductory undergraduate geoscience classes, either as a series of separate 30 to 50-minute in-class activities, as a single concentrated lab activity, or as homework assignments. In addition to developing content knowledge about proxy records of climate change, orbital periodicity, and glacial-interglacial cycles, students also develop and practice their skills in making observations, interpreting data from graphs, photos, and tables, constructing hypotheses, performing calculations, identifying and evaluating assumptions and uncertainties, and communicating scientific results. This exercise set is currently being tested in courses at 4 colleges and universities, and is part of a larger undergraduate curriculum called “Building Core Knowledge and Reconstructing Earth History”, which uses authentic data to teach anchor concepts of climate change through sediment core archives (NSF Grant # 0737335).