APES Objectives – Unit 9

Summary

Unit 9, “Global Change,” is the most heavily weighted unit on the AP Exam, at 15-20%. It addresses large-scale environmental issues and their impacts on the planet. The unit explains the importance of the stratospheric ozone layer and the causes and effects of its depletion. It identifies the main greenhouse gases and their sources, explaining how the greenhouse effect leads to global climate change. The unit details the various impacts of global climate change on ecosystems, including rising temperatures, melting ice, and changes to oceanic currents. It also covers ocean warming and ocean acidification, explaining their causes and effects on marine life, especially coral reefs. Finally, the unit discusses the problems associated with invasive species and the factors that lead to endangered species and a decrease in biodiversity, offering mitigation strategies for these issues.