Which phenomenon does NOT affect the climate of a geographical area?

The phenomenon that does not affect the climate of a geographical area is population density. Climate is primarily influenced by natural environmental factors like elevation, latitude, and proximity to water bodies.

Elevation affects climate because as altitude increases, temperature generally decreases, leading to different climatic conditions at different heights. Latitude is crucial because it determines the angle and intensity of sunlight that reaches a given area, deeply influencing temperature and seasonal variations. Proximity to water also plays a significant role; areas near large bodies of water can experience milder climates due to the water's ability to regulate temperature and moisture levels.

In contrast, while population density may influence local ecosystems and urban microclimates by increasing heat due to human activity, it does not have a direct impact on the broader climatic patterns of an area. Thus, it is the correct choice as it does not fundamentally alter the climate in the same manner as the other listed phenomena.