Los Angeles is located in a desert climate zone, where the scarcity of water typically makes it difficult for large cities to develop. However, Los Angeles grew into the largest city in the western United States. One contributing factor was the rise of the film industry in the early 1900s. At that time, lighting and filming technology were not yet advanced, so abundant sunlight was essential for film production. Los Angeles was able to produce films with clearer visuals than any other region. This intense sunlight, combined with America’s growing car culture, gave rise to a unique air pollution phenomenon known as “Los Angeles smog.”