Investigate the interrelationships of the natural world and analyze environmental problems with our comprehensive AP® Environmental Science study resources. This section features a wide array of academic documents organized by the nine course units, covering topics such as ecosystems, biodiversity, populations, and earth systems. You will find high-quality study guides that simplify complex biogeochemical cycles—like the nitrogen and carbon cycles—alongside detailed notes on energy resources, atmospheric pollution, and global change. Whether you are mastering the math required for the “no-calculator” era of the exam or practicing the design of controlled experiments for the free-response section, these resources provide the scientific depth and analytical tools necessary to excel on the AP® exam.