This activity is used in an undergraduate course in hydrochemistry.

• understanding of atmospheric and hydrospheric composition and processes
• basic understanding of carbon cycling and feedback
• basic understanding and use of the internet

This exercise is conducted during the second or third week of class, after three to six lecture-hours of introductory material at the beginning of the semester.

• understanding geochemical cycling over geologic time
• understanding global change over geologic time

• critical thinking skills
• use and document computer and print resources
• synthesis of ideas

• Initial exercise to generate free discussion in the classroom, establish ease of asking questions, and create an environment in which students can interact, discuss topics, and develop teamwork
• oral presentation in debate format

Geochemistry is often taught as a set of hard and fast principles. While it is necessary to impart a certain amount of information to understand geochemistry, it often appears to students as though there is only one interpretation of the data based on professorial opinion, group dynamics, literature review, and even political issues. By organizing a debate on a controversial topic early in the term, students are put in the position of learning beyond the classroom, and articulating their ideas to their group and before the class. In addition to course goals of promoting understanding of geochemical cycling and global warming, developing group rapport, and encouraging use of external resources, this exercise helps students to become better informed citizens.

Evaluation is based partly on group effort; some members may receive a higher score based on their contributions to the presentation and class discussion. Students are evaluated on their demonstrated understanding of class material as indicated by their use of such material in their presentations. They are evaluated on their use of outside materials, including the acquisition of appropriate materials, synthesis of concepts, demonstrated depth and breadth of understanding. They are evaluated on their response to issues raised by other teams. They are evaluated in accordance with the timing of the activity relative to the term.