An urban heat island (UHI) is a metropolitan area that is a lot warmer than the rural areas surrounding it. Heat is created by energy from all the people, cars, buses, and trains in big cities, and (18) __________. There are many reasons for UHIs. When houses, shops, and industrial buildings are constructed close together, it can create a UHI. Building materials are usually very good at insulating, or holding in heat, and this insulation makes the areas around buildings warmer. Waste heat also contributes to a UHI. People and their tools, such as cars and factories, (19) __________, whether they are jogging, driving, or just living their day to day lives. The energy people burn off usually escapes in the form of heat. Urban areas are densely populated, (20) __________, and they are also densely constructed, meaning buildings are constructed very close together. When there is no more room for an urban area to expand, engineers build upward, creating skyscrapers. All this construction means waste heat, and heat that escapes insulation, has nowhere to go, so it lingers in and between buildings. (21) __________. Urban heat islands can have worse air and water quality than their rural neighbors, and UHIs contribute to energy demands in the summer, sometimes leading to rolling blackouts. Because of these negative effects, scientists say city dwellers, architects, and designers have to work not only to reduce people’s impact on urban areas, but also (22) __________ that reflect more sunlight and trap less heat. [Adapted from https://education.nationalgeographic.org] |
