A student is writing a report on urban heat islands and has gathered the following notes:
• Note 1: A 2022 EPA study found that urban areas can be 1–7°F hotter than surrounding rural areas due to reduced vegetation and increased impervious surfaces.
• Note 2: Researchers at Arizona State University found that white rooftops reduced indoor cooling costs by up to 20% in Phoenix.
• Note 3: A meta-analysis of 50 cities found that urban tree canopy coverage correlated with a 2.5°F average temperature reduction, but only when coverage exceeded 25%.
• Note 4: Critics of green infrastructure argue that trees require significant water resources, which may strain municipal supplies in arid climates.
Which of the following most effectively uses all four notes to present a balanced synthesis?
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A
Urban heat islands pose serious challenges, and while both reflective roofing and increased tree canopy have demonstrated measurable cooling effects, the efficacy of tree-based solutions is threshold-dependent and may be counterproductive in water-scarce regions.
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B
Urban areas are significantly hotter than rural ones, but reflective roofing and tree canopy can both solve this problem if cities invest in green infrastructure.
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C
Because trees strain water supplies in arid climates, cities should prioritize reflective roofing over tree canopy, as the EPA confirms urban areas are already too hot.
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D
The best way to address urban heat islands is to combine white rooftops with tree canopy coverage, since both have proven effective according to recent studies.