Which of the following is an example of green infrastructure?

• A. A paved arterial road.
• B. Green roofs.
• C. A glass office building.
• D. An industrial smokestack.

Answer: (B)

Green infrastructure uses living systems and natural processes to deliver services in urban areas, such as managing stormwater, cooling the environment, and providing habitat. Green roofs embody this idea because they add soil and vegetation to building rooftops, which helps absorb rainfall, reduce runoff, insulate and cool the building, and create urban habitat. The other options are traditional gray infrastructure or built forms that don’t deliver those ecosystem services: a paved arterial road is an impermeable surface that increases runoff; a glass office building is a standard structure without vegetation to provide stormwater or cooling benefits; an industrial smokestack is a pollution-emitting feature, not a green infrastructure element.