How is urban heat island effect primarily caused?

The urban heat island effect is primarily caused by human activities and land modifications. In urban areas, the extensive use of materials such as concrete, asphalt, and brick significantly alters the local environment. These materials absorb and retain heat more than natural landscapes like forests or grasslands, leading to increased surface temperatures. Additionally, urbanization often reduces vegetation, which would otherwise provide cooling through processes such as transpiration and shading.

Other contributing factors include increased energy consumption in cities, which generates waste heat, and the concentration of infrastructure, buildings, and vehicles that contribute to elevated temperatures. As cities grow and become more densely populated, these human modifications intensify the urban heat island effect by creating microclimates that can be significantly warmer than surrounding rural areas.