Question 89·Medium·Central Ideas and Details
Green roofs are layers of vegetation installed on top of buildings. Ecologists Linda Gomez and Arthur Patel compared city blocks with and without green roofs during summer heatwaves. They found that roof surfaces on buildings with green roofs were up to 15 °C cooler than those without, and street-level air temperatures nearby were about 2 °C lower. Gomez and Patel concluded that although a single green roof only slightly cools the surrounding air, implementing many green roofs across a neighborhood could meaningfully lessen the urban heat-island effect.
According to the report, what did Gomez and Patel conclude about the potential impact of widespread adoption of green roofs?
For “According to the passage/report” questions about conclusions, go straight to where the author’s conclusion is explicitly stated—often in the final sentence or two. Underline the key idea and its strength (for example, “slight,” “meaningful,” “eliminate”). Then, paraphrase that idea in your own words and compare it to each choice, eliminating any options that (1) contradict the passage’s data, (2) introduce new topics the passage never mentions (like costs, if not discussed), or (3) exaggerate the claim beyond what is stated. Choose the option that most closely matches both the content and the strength of the original conclusion.
Hints
Find where the authors state their conclusion
Look for the sentence that actually starts with “Gomez and Patel concluded that…” near the end of the passage. That’s where their main conclusion is stated.
Focus on the effect of many green roofs
The question asks about widespread adoption. Pay attention to what the passage says about “implementing many green roofs across a neighborhood,” not just about a single roof.
Pay attention to what is and is not mentioned
Ask yourself: Do the authors talk about maintenance costs or about replacing other cooling strategies, or do they focus on something else? Eliminate any options that bring in ideas not mentioned in the passage.
Look at the strength of the claim
Notice how strongly the passage describes the effect (for example, whether it suggests a small change, a meaningful change, or a complete solution). Choose the option whose strength matches the wording in the passage.
Step-by-step Explanation
Identify what the question is asking
The question asks specifically about Gomez and Patel’s conclusion regarding the potential impact of widespread adoption of green roofs.
So you should look for where the authors state their conclusion and what they say would happen if many green roofs were installed, not just one.
Locate the authors’ conclusion in the passage
Look near the end of the passage, where conclusions are usually found. The sentence beginning “Gomez and Patel concluded that…” is the key.
That sentence says that although one green roof only slightly cools the surrounding air, “implementing many green roofs across a neighborhood could meaningfully lessen the urban heat-island effect.”
Paraphrase the key conclusion in your own words
Restate that final sentence: if many buildings in an area had green roofs, the combined effect could significantly reduce the urban heat-island effect.
Notice that the conclusion is about the overall city or neighborhood climate effect, not about costs or completely replacing other strategies.
Match the paraphrased conclusion to the answer choices
Now compare your paraphrase to the options:
- The passage’s conclusion is that many green roofs together could meaningfully lessen (significantly reduce) the urban heat-island effect.
- Choice A, “It could substantially lessen the heat-island effect in cities,” directly matches this idea.
Therefore, the correct answer is A) It could substantially lessen the heat-island effect in cities.