Students learn how rooftop gardens help the environment and the lives of people, especially in urban areas. They gain an understanding of how plants reduce the urban heat island effect, improve air quality, provide agriculture space, reduce energy consumption and increase the aesthetic quality of cities. This draws upon the science of heat transfer (conduction, convection, radiation, materials, color) and ecology (plants, shade, carbon dioxide, photosynthesis), and the engineering requirements for rooftop gardens. In the associated activity, students apply their scientific knowledge to model and measure the effects of green roofs.