Zakia D. Parrish, Ph.D.
This unit is intended for ninth grade Science students enrolled in a Physical Chemistry or Integrated Science course; however it can also be used in a Chemistry or Environmental Science course. I teach at a health sciences, business, and technology magnet high school in New Haven. Our students live in New Haven, as well as seventeen surrounding cities and towns including Branford, Wallingford, Ansonia, West Haven, and Hamden. This is a relatively small school with approximately 750 students, of which twenty-five percent are freshmen and over sixty percent of the ninth graders are female. A typical class consists of fifty-five percent African American, thirty-three percent Latino, seven percent Caucasian, and five percent Asian and Middle Eastern.
This unit is based on 82 minute block periods that meet every other day and is a part of a larger unit that on Global Interdependence and henceforth will be referred to as the "subunit". This is part of the Connecticut State Science Standards, Content Standard 9.8, in which students learn how the use of resources by human populations affects the quality of the environment. One of the state mandated expected performances (D22) for this standard is that students be able to explain how the accumulation of carbon dioxide in the atmosphere increases Earth's "greenhouse" effect and may cause climate changes. The larger unit will span an entire marking period, approximately 8 weeks.
Encouraging students to access their prior knowledge of other science topics and apply them to new content is highly desirable. Thus students need to be well aware of the basic biogeochemical cycles, specifically the carbon and water cycles and the layers of the Earth's atmosphere. They will also need to understand phase changes and the differences in the amount of heat energy in solids, liquids and gases. Students should also understand the periodic table and the types of bonds formed between atoms to make compounds. A basic understanding of fossil fuels and the resulting products of combustion of these products will also be helpful. This knowledge will be critical as students will need to identify what the various greenhouse gases are and how they are connected to these cycles. We will discuss what the greenhouse effect is, how it has changed over time, and who the 'culprits' or responsible compounds are that contribute it. Students will be able to relate the material in this subunit to their lives and see how everyday activities impact not only their community, but also the environment on a global scale.