Some environmental benefits of urbanization include conservation of energy and resources producing a smaller carbon footprint, whereas a challenge of urbanization is controlling growth and development. Urbanization is the process of growing the population in cities and suburbs.
The standards for what is considered urbanized varies by country. In the United States, any area with a population of 50,000 people or more is an urbanized area. In Asian countries, this number is much higher.
During the Industrial Revolution, rapid urbanization increased pollution and harmed the environment. Since then, industries like factories are more closely monitored to reduce the amount of pollution they release. Services like public transportation in urban areas reduce the need for residents to drive individual cars, reducing the amount of pollution in the area. In addition, many urban areas have dedicated green areas, and the close proximity of stores, restaurants, and employment often leads people to walk or bike around the city. Providing electricity, sewage and other public services is much easier and less expensive when the population is concentrated in one area.
As cities expand, planners face the challenge of limiting the reduction of natural areas and habitats on the city's outer edges. Typically, city planners try to preserve as much of the natural environment as possible while also adding space for housing and industry.