In this optional lesson, students compare the energy used to make paper from two different sources: tree fiber or recycled material. This lesson begins with a Warm-up meant to familiarize students with vocabulary related to energy consumption and carbon dioxide emission. This promotes students’ making sense of the problem and their perseverance in solving it (MP1). They then analyze the current consumption and emission of two paper mills and construct arguments regarding whether or not one of the paper mills should change the material used to create paper (MP3).

This lesson can be used anytime after Unit 2 is completed.