AP® Environmental Science Unit 9 Review and Practice Test
Master Unit 9 AP® Environmental Science with this complete review on global change, climate impacts, and sustainability. Our APES Unit 9 review covers how natural and human factors influence climate, supported by interactive lessons, videos, and AP Environmental Science Unit 9 practice questions that mirror the real exam.
Explore topics like greenhouse gases, sea level rise, and ecosystem responses to global change. Strengthen your understanding with step-by-step explanations and realistic Unit 9 APES practice tests designed to boost your exam readiness.
Understand Global Change Clearly with Our APES Unit 9 Review
Dive into AP Environmental Science Unit 9 with a clear breakdown of global change, climate shifts, and human impacts on Earth’s systems. Our APES Unit 9 review simplifies complex ideas with visuals, real examples, and guided practice so you can understand the material quickly and feel prepared for your exam.
Engaging Video Lessons
Explore AP Environmental Science Unit 9 topics through clear, engaging video lessons that make global change easier to understand. Each lesson breaks down climate drivers, atmospheric trends, and human impacts with simple visuals and real-world examples. These videos help you connect complex processes and prepare confidently for APES Unit 9 MCQs, progress checks, and FRQs.
Interactive Study Guides
Work through AP Environmental Science Unit 9 with interactive study guides that simplify global change concepts step by step. These guides break down climate patterns, atmospheric changes, greenhouse gases, and ecological responses using visuals and clear explanations. Each section reinforces learning with quick checks and examples so you can stay confident during your APES Unit 9 review and exam prep.
Sharpen Your APES Skills with Unit 9 Practice Questions
Question
Which of the following best describes one way the Endangered Species Act helped protect animal populations?
| A. Established the first protected area for the National Wildlife Refuge System. | |
| B. Mandated landowners to control the population size of naturally occurring species that prey on endangered species. | |
| C. Created penalties for developing countries that engage in the sale of products made from endangered species. | |
| D. Introduced regulatory measures stating that federal agencies cannot destroy the habitat of endangered species. |
Explanation
During the 20th century, the human population began a period of rapid growth. This growth led to an increase in housing and commercial development that resulted in fragmented habitats. The loss of habitat, combined with increased threats from hunting and pollution, caused a decrease in biodiversity across the globe.
The US government, driven by this loss of biodiversity, enacted the Endangered Species Act (ESA) in 1973. Key provisions of the ESA protected animals by:
- creating a system to list animals as threatened or endangered.
- prohibiting the import, export, possession, hunting, sale, and transport of listed species.
- designating critical habitat (protected land necessary for the survival of a listed species).
Within the critical habitat provision, the ESA states that the habitat of endangered species cannot be destroyed by individuals or by federal agencies. Through this provision, protected animal habitats enabled the recovery of some threatened species, such as the whooping crane.
(Choice A) The first protected area for the National Wildlife Refuge System was created in 1903; it was not part of the ESA.
(Choice B) Through incentive programs, the ESA encourages rather than mandates landowners to protect endangered species in this way.
(Choice C) Although the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) provides funds to reduce the sale of products from endangered species, the ESA—a US law—does not penalize other countries.
Things to remember:
The Endangered Species Act, a US law, increases protection of
habitats to safeguard threatened animal populations.
Question
Other than rising sea levels, which of the following is a consequence of climate change?
| A. Changes in climate slow the rate at which carbon dioxide is stored in the tissues of producers. | |
| B. The ecological range of tolerance for marine species narrows to protect species from temperature fluctuations associated with climate change. | |
| C. Thermal inversions occur more readily with climate change, impacting the formation of ozone in the stratosphere. | |
| D. Climate change poses a threat to the availability of habitat and food for organisms in polar regions. |
Explanation
Throughout Earth's history, the prevailing climate (average temperature and rainfall over time) has varied, with cyclical periods of warming and cooling. However, in recent history, anthropogenic activities have contributed to a period of significant warming, which has influenced Earth's biotic and abiotic factors in many ways.
For example, as temperatures rise, the snow and ice in polar regions begin to melt. Because many polar species, such as polar bears and seals, are adapted to snow and ice, changes in the climate of polar regions impact their survival by reducing the availability of habitat and food.
(Choice A) Increased atmospheric carbon dioxide levels from climate change can promote photosynthesis and plant growth that would increase, not slow, the rate of carbon dioxide storage in producers.
(Choice B) A narrow range of tolerance would limit the temperatures that organisms are adapted to and would not protect species from fluctuations in the temperature.
(Choice C) Thermal inversions do not impact the formation of the ozone layer.
Things to remember:
As the climate changes and surface temperatures warm, snow and ice in
polar regions melt, resulting in decreased habitat and availability of food for some polar species.
Passage
The diagram below shows stratospheric ozone depletion over time.
Question
Which of the following best explains an anthropogenic cause of the ozone depletion illustrated in the diagram?
| A. Increased atmospheric sulfur dioxide concentrations from the burning of fossil fuels and vehicle emissions. | |
| B. Increased atmospheric sulfur dioxide concentrations from volcanic eruptions and coal-burning power plants. | |
| C. Increased atmospheric chlorofluorocarbon concentrations from concentrated animal feeding operations and integrated pest management practices. | |
| D. Increased atmospheric chlorofluorocarbon concentrations from aerosol sprays and refrigerants. |
Explanation
In the early 20th century, chlorofluorocarbons (CFCs) were synthesized as an inexpensive and effective group of gases that could be used in aerosol sprays and in cooling systems. By the 1960s, CFCs were widely used in automobiles, homes, and office buildings.
However, in the early 1970s, scientists discovered that chlorine atoms in CFCs could destroy stratospheric ozone. When the depletion of the ozone layer above Antarctica was observed in the mid-1980s, scientists quickly connected it to CFCs. Therefore, increased atmospheric chlorofluorocarbon concentrations from aerosol sprays and refrigerants is the best explanation for an anthropogenic cause of the ozone depletion illustrated in the diagram.
(Choices A and B) Although sulfur dioxide is produced by the combustion of fossil fuels and volcanic eruptions, it does not contribute to the depletion of the ozone layer.
(Choice C) Concentrated animal feeding operations and integrated pest management practices are not sources of CFCs and do not increase atmospheric CFC concentrations.
Things to remember:
Anthropogenic causes of stratospheric ozone depletion include the
emissions of chlorofluorocarbons (CFCs), a group of gases extensively used in the early 20th century.
On-the-Go Companion for AP Environmental Science
Prepare for AP Environmental Science Unit 9 whenever it fits your day with the UWorld app. Review global change videos between classes, go through climate and atmospheric change study guides while commuting, or solve APES Unit 9 practice questions during short breaks. Every tool you need, MCQs, FRQs, progress-check style practice, and explanations, is always available.
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Frequently Asked Questions (FAQs)
What are the main topics covered in AP Environmental Science Unit 9 Global Change?
AP Environmental Science Unit 9 explores how natural processes and human activities create large-scale changes in Earth’s systems. The unit focuses on long-term environmental shifts, their drivers, and their ecological consequences.
Key topics in Unit 9 include:
- Ozone depletion: How CFCs and other chemicals break down the ozone layer and increase UV exposure.
- Global climate change: Long-term shifts in temperature, weather patterns, and atmospheric composition.
- Ocean warming and acidification: Rising sea temperatures and decreasing pH levels affecting marine life.
- Invasive species: How non-native species disrupt ecosystems and threaten native biodiversity.
- Human impacts on diversity: Habitat loss, pollution, and resource use driving species decline worldwide.
UWorld helps you master all aspects of Unit 9 with clear explanations, visual breakdowns, and realistic APES Unit 9 practice questions, making complex global change topics easier to understand and boosting your exam confidence.
How should I prepare for an AP Environmental Science Unit 9 exam?
Preparing for AP Environmental Science Unit 9 starts with building a strong understanding of global change and the environmental processes that drive it. Instead of studying everything at once, begin by breaking the unit into smaller themes, climate change, ozone depletion, ocean changes, invasive species, and biodiversity loss.
Next, strengthen your understanding with resources that turn these topics into clear visual explanations. For Unit 9, it’s especially important to review charts, climate models, atmospheric data, and long-term trend graphs. Short videos and guided notes make it easier to grasp how these global processes interact.
Finally, practice regularly with exam-style questions. Work through APES Unit 9 progress-check style MCQs, data interpretation problems, and FRQs that ask you to analyze climate patterns or evaluate human impacts. UWorld ties all of this together by giving you realistic Unit 9 practice questions, visual explanations, and step-by-step breakdowns, making even the most complex global change concepts feel manageable.
Are any free resources available for AP Environmental Science Unit 9?
Yes, you can find several helpful free resources for AP Environmental Science Unit 9, starting with the UWorld free trial. It includes a limited set of AP Environmental Science Unit 9 MCQ practice questions, targeted explanations on global change topics, and sample AP Environmental Science Unit 9 FRQ items that show you how exam-style answers are structured. You can also preview APES Unit 9 vocab, quick summaries, and a unit 9 APES reading guide to support your review.
The College Board provides additional support through AP Classroom, including topic questions, progress-check style items, and a Unit 9 APES quiz that reflects the exam’s structure. Their outlines also help you understand exactly what the Global Change unit expects.
Finally, Khan Academy offers general environmental science videos that can help reinforce major ideas. While not AP-specific, they can still support your understanding of atmospheric changes, climate trends, and biodiversity concepts.
What types of questions are on the AP Environmental Science Unit 9 test?
The AP Environmental Science Unit 9 test includes both multiple-choice and free-response questions that focus on global change, climate patterns, human impacts, and biodiversity loss. You’ll encounter data sets, graphs, atmospheric trends, and real-world scenarios that require you to connect environmental processes with global outcomes.
- Multiple-Choice Questions (MCQs): Expect AP Environmental Science Unit 9 MCQ items covering ozone depletion, greenhouse gas trends, ocean acidification, and invasive species. Many questions mirror the format of a unit 9 APES MCQ progress check or an APES Unit 9 MCQ progress check, where you interpret charts, climate models, or short passages to choose the best answer.
- Free-Response Questions (FRQs): The AP Environmental Science Unit 9 FRQ section often includes data interpretation, short calculations, and explanations of environmental change. You may analyze ecosystem responses, evaluate human impacts, or interpret climate graphs. Reviewing APES Unit 9 FRQ answers and reading an APES Unit 9 summary can help you understand how high-scoring responses are structured.
UWorld recreates all of these question types with exam-style detail, helping you practice exactly what you’ll see on the APES Unit 9 test and build confidence with every session.
How can I improve my score on the Free-Response Questions (FRQs) for Unit 9?
Improving your FRQ score for AP Environmental Science Unit 9 starts with consistent practice. Work through past exam FRQs and sample questions to familiarize yourself with the types of prompts you’ll encounter, such as those on population dynamics, species interactions, and ecosystem services.Avoid common mistakes like skipping calculations or misinterpreting data presented in charts and graphs.
Next, refine your writing and time management skills. Break down each question into smaller parts, plan your responses briefly, and practice completing FRQs within the allotted time.
For the most effective preparation, UWorld’s AP Environmental Science resources provide realistic FRQs with step-by-step explanations, targeted feedback, and customizable quizzes. Practicing with UWorld helps you identify weak areas, reinforces key concepts, and builds confidence so you can approach Unit 9 FRQs with clarity and precision on test day.
What is the "Global Change" unit's weight on the AP Environmental Science exam?
The “Global Change” unit, which is AP Environmental Science Unit 9, typically accounts for about 15–20% of the multiple-choice section and a similar portion of the free-response section on the AP exam. This unit covers topics such as climate change, ozone depletion, biodiversity loss, and the impact of human activities on global systems, making it an important area for understanding both current environmental challenges and long-term ecological trends.
UWorld’s APES practice questions allow you to focus on Unit 9 with realistic multiple-choice questions and FRQs. Their explanations highlight the connections between global change concepts and other units, helping you maximize your score efficiently.
Where can I find a good study guide for AP Environmental Science Unit 9?
A highly effective way to study for AP Environmental Science Unit 9 is to use UWorld’s APES study guide. UWorld provides a structured, topic-by-topic review of Unit 9 concepts, including global change, climate effects, and biodiversity loss. Their study guide combines clear explanations, diagrams, and practice questions that mimic the style and difficulty of the AP exam. You can also track your progress, identify weak areas, and customize quizzes to focus on the topics you need most.
In addition to UWorld, the College Board offers official resources, including course descriptions and sample FRQs, which are essential for understanding how Unit 9 topics appear on the exam.
Khan Academy is another excellent free resource, providing video tutorials and practice exercises that explain complex concepts in an easy-to-understand format.
Can I find practice tests specifically for APES Unit 9?
Yes, UWorld offers practice tests and question banks that are perfect for focusing on AP Environmental Science Unit 9 (Global Change). You can create custom quizzes and practice tests that concentrate only on Unit 9 topics, such as climate change, biodiversity loss, and human impacts on ecosystems. The platform provides multiple-choice and free-response questions designed to mirror the style and difficulty of the actual AP exam.
UWorld also gives detailed explanations for each question, helping you understand why certain answers are correct and where you might need improvement. Their progress-tracking tools let you see which topics you’ve mastered and which need more review, making your practice highly targeted.
Using UWorld for Unit 9 ensures that your preparation is efficient, structured, and closely aligned with the AP exam format, helping you build confidence and improve your score.
