Plan environmental research and assess evidence
Turn an environmental question into a testable investigation and evaluate how evidence, data integrity and scientific ideas develop.
Section 2.2 · Environmental research in the context of climate change
Exam scope and assessment notes
Original StudyForA teaching and practice, not Cambridge-authored questions, mark schemes or official grades. Cambridge expects candidates to study all eight topics, carry out investigative work and learn teacher-selected case studies. This course does not replace a centre's named case-study examples, current local environmental data, supervised fieldwork or the candidate's own investigation. Practice datasets are illustrative, not observations from a real place. No official assessment or certification is provided. The examples and practice datasets in these lessons are fictional and formative; learners must add their centre's verified case studies and current local evidence.
Before you begin
- Cambridge recommends prior environmental/science study equivalent to IGCSE or O Level. This is an AS-only qualification; use the exam-year syllabus and confirm centre entry details.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What makes environmental evidence useful?
What you will learn
- Describe how observations, questions, hypotheses and testing interact
- Plan a method that can test a stated environmental question
- Assess source, date, method, uncertainty and alternative explanations
Design around a question
A testable question identifies what will be measured, where or when, and which relationship is being investigated. A hypothesis predicts a pattern that could be checked against observations.
Specify variables, controls, units, sampling, repeats and safety. A method should be repeatable, ethical and suited to the question; a correlation can support an association without proving a single cause.
Evaluate climate evidence and data integrity
Environmental data come from observations, instruments, models and historical records. Compare collection methods, coverage, time span, uncertainty and whether independent sources agree.
Scientific explanations are refined as new evidence is collected. A proposed mechanism, including research into ozone depletion, is strengthened by testable predictions and corroborating observations, not confidence or repetition alone.
Sources for this lesson
Pause and explain
What makes an environmental hypothesis testable?
Worked example
A student asks whether shade is associated with soil temperature in a school garden. Outline a testable method.
Show the worked solution
- Define shade and soil temperature operationally.
- Select comparable sampling points and a repeated measurement time.
- Record soil moisture and other conditions that may affect temperature.
Answer Measure soil temperature at a fixed depth at shaded and unshaded points using the same calibrated probe, repeat at comparable times and record moisture and recent weather. The design can test an association; it cannot prove shade is the only cause unless other influences are controlled.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A report claims that a warmer year proves a long-term climate trend. What evidence checks should a student make?
Give me a hint
Check duration, measurement consistency and corroboration.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply describe how observations, questions, hypotheses and testing interact to the stated context.
- Explain the inference and one limitation or trade-off.
One warm year is weather variability, not by itself a long-term climate trend. Check a longer consistent record, measurement methods, spatial coverage and independent indicators, then describe uncertainty rather than relying on one unusual year.
Look for these in your work
- Describe how observations, questions, hypotheses and testing interact
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
A river survey finds fewer invertebrates downstream of a factory. Give a cautious conclusion and two further checks.
Give me a hint
State the pattern, not an unproven cause.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply plan a method that can test a stated environmental question to the stated context.
- Explain the inference and one limitation or trade-off.
The sampled downstream sites had fewer recorded invertebrates than the sampled upstream sites. This association may relate to water quality, but habitat, flow, season and sampling effort could also differ. Measure relevant pollutants and repeat comparable samples across sites and times.
Look for these in your work
- Plan a method that can test a stated environmental question
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
Two climate datasets show different temperature trends. How should a researcher compare them?
Give me a hint
Check definitions, coverage and processing before choosing a result.
Compare my reasoning
- Identify the relevant data, place or process in the prompt.
- Apply assess source, date, method, uncertainty and alternative explanations to the stated context.
- Explain the inference and one limitation or trade-off.
Compare the time periods, station coverage, calibration, missing-data handling, spatial resolution and uncertainty. Explain whether each dataset measures the same quantity. Use corroborating sources and report why the trends differ instead of selecting the more convenient one.
Look for these in your work
- Assess source, date, method, uncertainty and alternative explanations
- Uses relevant evidence and explains the environmental mechanism
- Distinguishes observation, inference and limitation
Common mistakes
- Writing an aim that cannot be measured
- Using a model as if it were a direct observation
- Selecting only evidence that supports a preferred conclusion
What can you explain now?
What makes an environmental hypothesis testable?
Compare with the explanation
It predicts a measurable pattern that a stated method can check
A measurable prediction can be compared with observations and may be revised.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Why does a correlation between an environmental pressure and an impact not automatically prove causation?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.