What does the "urban heat island effect" refer to?

The urban heat island effect refers to the phenomenon where urban areas experience significantly higher temperatures than their surrounding rural areas. This temperature difference is primarily due to human activities, urban development, and the materials used in city construction, such as asphalt and concrete, which absorb and retain heat. Urban areas often have fewer trees and vegetation compared to rural settings, which also contributes to this warming effect. The dense concentration of buildings, roads, and vehicles contributes to increased heat retention, leading to higher overall temperatures in cities, especially during the day and at night.

The other options focus on cooling effects or decreases in temperature, which do not accurately describe the urban heat island effect. This concept highlights the challenges of urbanization, including energy consumption and public health implications, as cities can become notably warmer, which affects climate and living conditions.