Which combination best represents adaptation strategies for urban heat island effects?

• A. Green roofs
• B. Urban forestry
• C. Green roofs and reflective surfaces
• D. More concrete and asphalt

Answer: (C)

Adaptation to urban heat island effects focuses on reducing heat gain and increasing cooling in built-up areas. Urban heat islands happen because dark, dense surfaces like concrete and asphalt absorb a lot of solar energy and store heat, while limited vegetation reduces shade and cooling from evaporation. To counter this, strategies combine vegetative approaches with reflective materials. Green roofs provide insulation and evaporative cooling, while urban forestry adds shade and extra cooling through transpiration. Reflective surfaces increase the albedo of roofs and pavements, reflecting more sunlight and absorbing less heat. The combination of green roofs and reflective surfaces uses both mechanisms—evapotranspiration-driven cooling and reduced heat absorption—leading to greater temperature reductions than either approach alone. Adding more concrete and asphalt would worsen heat absorption, so the best option integrates both vegetation-based cooling and reflective surfaces.