AP Environmental Science Science Practice 7 - Environmental Solutions is the skill of proposing and justifying solutions to environmental problems. You describe a problem, suggest a response, weigh the tradeoffs, and back your proposed solution with data and clear reasoning. This is the most action-focused practice in the course, since it asks you to move from understanding a problem to recommending what to do about it.

Practice 7 is also the heaviest practice on the exam. It makes up 17 to 23 percent of the multiple-choice section and 26 to 34 percent of the free-response section, and it is assessed in all three FRQs. If you get comfortable with these skills, you set yourself up well across the whole test.

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What Science Practice 7 - Environmental Solutions Means

Most environmental science is about identifying problems and figuring out what humans can do about them. Practice 7 puts that full cycle into one skill set.

You will be expected to:

Name and describe a real environmental problem.
Suggest a response or approach to that problem.
Explain the upsides, downsides, and unintended effects of a solution.
Use data and evidence to support a solution.
State a clear claim that proposes a solution in a specific situation.
Justify that solution by explaining its advantages.

Notice the arc here. It runs from describing the problem to proposing and defending a fix.

What This Practice Requires

Practice 7 breaks into six subskills. Here is what each one asks you to do.

7.A Describe environmental problems. Clearly state what the problem is and what is happening. Example: excess nitrogen runoff from fertilizer enters a lake and causes eutrophication.

7.B Describe potential responses or approaches to environmental problems. Suggest a method or action that could address the problem. Example: use buffer strips of vegetation along fields to absorb nutrient runoff before it reaches the water.

7.C Describe disadvantages, advantages, or unintended consequences for potential solutions. Explain the tradeoffs of a proposed approach. A multiple-choice item on this subskill asked which option is a disadvantage of genetically modifying crops, with the correct answer being that genetic modifications can decrease the genetic diversity of crop species.

7.D Use data and evidence to support a potential solution. Pull numbers, trends, or research findings and connect them to your proposed solution. This often means reading a graph or table and saying how it backs your recommendation.

7.E Make a claim that proposes a solution to an environmental problem in an applied context. Write a direct statement that names a specific solution for a specific scenario. A claim is not a description. It is a recommendation.

7.F Justify a proposed solution by explaining potential advantages. Explain why your solution would work or help. This is the reasoning that connects your claim to the outcome you expect.

Skills You Need for This Practice

These habits make Practice 7 questions much easier.

Separate problem from solution. First state what is wrong, then state what to do.
Write claims as clear recommendations. Use language like "One solution is to..." or "The community should..."
Always pair advantages with disadvantages. Solutions in this course rarely have only upsides.
Tie evidence to the claim. Do not just describe a graph. Say how the data supports the action you propose.
Think about unintended consequences. A fix for one problem can create a new one, such as a dam improving energy supply while harming downstream fish populations.
Stay specific to the scenario. Applied context means your answer should match the place, species, or situation in the prompt.

How It Shows Up on the AP Exam

Practice 7 appears in both sections of the exam.

Multiple choice (17 to 23 percent of that section). Items often ask you to identify a disadvantage, advantage, or unintended consequence of a solution, or to pick the best response to a stated problem.

Example aligned to 7.C:

Which of the following is a disadvantage associated with the genetic modification of crops?

The correct answer is that genetic modifications can decrease the genetic diversity of crop species. Notice how it asks for a tradeoff, not a definition.

Free response (26 to 34 percent of that section, assessed in all three FRQs). Based on the exam structure, the FRQs are built to test this practice directly:

FRQ 1 asks you to design an investigation.
FRQ 2 asks you to analyze an environmental problem and propose a solution.
FRQ 3 asks you to analyze an environmental problem and propose a solution using calculations.

So two of the three free-response questions explicitly ask you to propose and justify a solution. On these, you will frequently write a claim (7.E), name a solution (7.B), explain its advantage (7.F), and support it with evidence (7.D).

This is practical advice and not an official scoring rule, but reading the verb in each FRQ part tells you which subskill to use. "Describe" points to 7.A or 7.B. "Identify a disadvantage" points to 7.C. "Propose" and "justify" point to 7.E and 7.F.

Examples Across the Course

Practice 7 shows up in nearly every unit because every unit has problems and possible fixes. Here are varied examples.

Unit 5, Land and Water Use. Problem: urban runoff carries pollutants into streams. Solution: install permeable pavement and rain gardens to reduce runoff volume. Advantage: less flooding and fewer pollutants reaching waterways. Tradeoff: higher installation cost than standard pavement.

Unit 6, Energy Resources. Problem: a region relies on coal, which emits carbon dioxide and particulates. Solution claim: the region should expand solar energy capacity. Justification: solar produces electricity without combustion emissions. Disadvantage to weigh: output varies with weather and time of day.

Unit 7, Atmospheric Pollution. This unit lists subskill 7.D directly. Problem: photochemical smog harms human health in a city. Solution: reduce vehicle emissions through public transit and tighter standards. Evidence: data showing pollutant levels dropping after similar policies were enacted.

Unit 8, Aquatic and Terrestrial Pollution. Problem: fertilizer runoff causes eutrophication in a lake. Solution: use integrated pest and nutrient management plus vegetative buffers. Advantage: lower nutrient loading reduces algal blooms. Unintended consequence to consider: changes in farming cost or yield.

Unit 9, Global Change. This unit highlights 7.D and 7.E. Problem: rising greenhouse gas concentrations drive climate change. Solution claim with data: a graph showing Arctic sea ice declining about 30 percent from 1980 to 2005 supports reducing emissions to slow the positive feedback loop of decreasing albedo and increasing ocean heat absorption.

These come from five different units, which shows that Practice 7 is a course-wide skill, not a single-topic one.

How to Practice Science Practice 7 - Environmental Solutions

Try these routines as you study.

Build a problem-solution-tradeoff chart for each unit. For every major problem, write one solution, one advantage, and one disadvantage.
Rewrite descriptions as claims. Take a fact and turn it into a recommendation. "Eutrophication harms lakes" becomes "Farmers should plant buffer strips to reduce nutrient runoff."
Practice connecting evidence to claims. Use a data set or graph and write one sentence that links a number to your proposed solution.
List unintended consequences on purpose. For every solution you propose, ask what new problem it might create.
Drill FRQ 2 and 3 prompts. Since both ask you to propose a solution, practice the full sequence of claim, solution, advantage, and evidence.

Common Mistakes

Describing a problem when asked to propose a solution. A claim must recommend an action.
Listing only advantages. Subskill 7.C wants tradeoffs and unintended consequences too.
Giving a solution with no reasoning. A claim without justification (7.F) is incomplete.
Ignoring the data. When a prompt gives a graph or table, your support should reference it, not generic facts.
Staying too general. Applied context means your answer should fit the specific scenario, location, or species in the question.
Mixing up the verbs. Describe, propose, and justify ask for different things. Match your answer to the verb.

Quick Review

Practice 7 is about proposing and justifying solutions to environmental problems.
It is the most weighted practice: 17 to 23 percent of MCQ and 26 to 34 percent of FRQ, assessed in all three FRQs.
The six subskills run from describing a problem (7.A) to justifying a solution by explaining advantages (7.F).
Always separate the problem from the solution, then weigh advantages and disadvantages.
A claim recommends an action; support it with data and reasoning.
FRQ 2 and FRQ 3 both ask you to analyze a problem and propose a solution, so practice the full claim-solution-advantage-evidence sequence.