♻️AP Environmental Science Review
AP Environmental Science covers 9 units, from The Living World: Ecosystems to Global Change. Review each unit with study guides, practice questions, and key terms — compiled by AP educators and updated for the 2027 AP exam.
AP Environmental Science is a college-level course where you analyze Earth's systems, human impacts, and sustainability using data, math, and evidence to explain problems and propose practical solutions.
Frequently Asked Questions
Is AP Environmental Science hard?
APES is one of the more manageable AP sciences, but it still asks for steady work. You cover 9 units that blend biology, chemistry, and earth science, plus real math on both sections. The free-response questions want specific evidence and clear reasoning, not vague answers. If you read consistently and practice data problems, you will find it very doable, especially since the topics connect to real issues you already care about.
How do I start studying for APES?
Start with Unit 1 and move through the 9 units in order, since later pollution and global change topics build on ecosystems, populations, and Earth systems. After each unit, review key terms, work through any math, and write short responses using specific evidence. Use unit study guides and practice questions to find weak spots early, then add timed FRQ practice as the exam gets closer.
Which APES units are weighted the most?
Unit 9: Global Change carries the most weight at 15 to 20 percent of the multiple-choice section. Units 3, 4, 5, and 6 each fall in the 10 to 15 percent range, so populations, Earth systems, land and water use, and energy resources matter a lot. Units 7 and 8 sit at 7 to 10 percent, while Units 1 and 2 are 6 to 8 percent. Prioritize the heavy hitters first.
How many FRQs are on the APES exam?
The free-response section has 3 questions worth 10 points each and 40 percent of your score, with 70 minutes total. Question 1 asks you to design an investigation. Question 2 asks you to analyze an environmental problem and propose a solution. Question 3 also asks you to analyze a problem and propose a solution, but with required calculations where you must show your work.
Do I need to know math for the APES exam?
Yes. Quantitative work shows up on both sections, and you can use a four-function, scientific, or graphing calculator throughout the exam. FRQ 3 requires calculations where you show every step and label units. Practice things like the 10 percent rule, half-life problems, percent change, and population rates so you can move through math quickly and earn the points.