A city is encouraging the use of 'green roofs' on new buildings. Besides providing insulation, what is a key environmental benefit of this type of roof?

They are the least expensive roofing option available.

They increase the building's solar reflection, significantly lowering city temperatures.

The vegetation can help manage stormwater runoff by absorbing rainwater.

The soil and plants are highly resistant to fire damage.

What is the primary scientific principle behind the effectiveness of a 'cool roof'?

It generates cool air through a chemical reaction.

It uses a thick layer of material to trap cool air inside.

It reflects a high percentage of solar radiation away from the building.

It absorbs heat during the day and releases it at night.

To reflect sunlight away from the building's surface.

To provide a waterproof barrier against rain and snow.

To reduce the rate of heat transfer between the inside and outside of the building.

To increase the structural strength of the roof deck.