In North America, other urban centers experienced a growth spurt during the Indu
In North America, other urban centers experienced a growth spurt during the Industrial Era. In 1800, the only city in the world with a population of over 1 million was Beijing, but by 1900, there were 16 cities with a population of over 1 million. The development of factories brought people from rural to urban areas, and new technology increased the efficiency of transportation, food production, and food preservation. For example, from the mid-1670s to the early 1900s, London increased its population from 550,000 to 7 million.
The growth in global urbanization in the 20th and 21st centuries follows the blueprint of North American cities. Still, it occurs much more quickly and at larger scales, especially in peripheral and semi-peripheral countries. Shanghai almost tripled its population from 7.8 million to 20.2 million between 1990 and 2011, adding the equivalent of the population of New York City in 20 years. It is projected to reach 28.4 million by 2025, third in size behind Tokyo (38.7 million) and New Delhi (32.9 million).
Urban Environmental Problems of the Developing World
Global urbanization reached the 50 percent mark in 2008, meaning that more than half of the global population lived in cities compared to only 30 percent 50 years ago. Access to basic services— clean water, sanitation, electricity, and roads—are some of the main urbanization challenges facing the developing world.
Municipal waste management is a crucial service cities provide, but it is often inefficient and underperforming in developing countries. Low-income countries face the most acute challenges with solid waste management. In low-income countries, cities collect less than half the waste stream. Of this, only about half is processed to minimum acceptable standards. Improper waste management, especially open dumping and open burning, significantly affects water bodies, air, and land resources. People who live near or work with solid waste have increased disease burdens. Unmanaged waste also frequently blocks drainage systems and worsens flooding. Even when collected and transported, waste in dumpsites and landfills contributes to greenhouse gas emissions.
Roughly 2.6 billion people in the developing world lack adequate sanitation, and facilities are often overloaded, disrepair, or unused. Even though the sanitation gap is twice as large as the water supply, investments in sanitation and hygiene have lagged far behind those in water and other “social” sectors, such as health and education. The main costs of urban sanitation services are sewers and sewage treatment. Whereas sewers contribute to public health by reducing everyday contact with sewage (especially by children), wastewater treatment is designed largely to meet ecological objectives and not public health ones. Urban utilities, by and large, are not well designed or staffed to address off-network solutions for water supply or sanitation, yet those solutions are likely to be the most important first steps of pro