Today in our environmental science lecture, we'll discuss urban heat islands. These are areas in cities that are significantly warmer than surrounding rural areas due to human activities and infrastructure. One key factor is the use of dark materials like asphalt and concrete, which absorb and re-radiate heat. Another contributor is the lack of vegetation, which reduces shade and evapotranspiration. To mitigate this, some cities have introduced green roofs, which are covered with plants, and cool pavements that reflect more sunlight. However, a major challenge is the initial cost of retrofitting existing buildings. Despite this, studies show that reducing urban temperatures by just 2 degrees Celsius can cut energy consumption for cooling by up to 20 percent.
❓ 강의에 따르면, 녹색 지붕과 쿨 포장재를 시행하는 데 있어 주요 장애물로 언급된 것은 무엇인가요?