James Lovelock first coined the term Gaia, a word that means viewing the Earth as a single living, breathing organism. A new scientific trend views the world's biggest cities the same way. More than half the world's population today lives in cities, and the world's largest urban areas are growing rapidly. The number of megacities (metropolitan areas with populations exceeding 10 million) has grown from just 3 in 1975 to about 20 today.
Researcher Charles Kolb reports that the concept of urban metabolism has existed for decades. It views large cities as living entities that consume energy, food, water, and other raw materials, and release wastes. The releases include carbon dioxide, the main greenhouse gas; air pollutants, sewage and other water pollutants; and even excess heat that collects in vast expanses of concrete pavement and stone buildings. Humans directly produce a significant share of this waste, but emissions from industrial, power generation and transportation systems respire the largest quantities of greenhouse gases and other air pollutants. Other urban metabolizers include sewage systems, landfills, domestic pets and pests like rats, which in some cities outnumber people.
Kolb says, "Carbon dioxide and other pollutants in megacities make them immense drivers of climate change. They impact climate on both a regional and global level because these long-lived greenhouse gases are dispersed around the world." One of his biggest concerns is that the most highly polluted megacities are in developing countries such as Dhaka, Bangladesh; Cairo, Egypt; and Karachi, Pakistan. Even the cleanest megacities like Tokyo/Osaka in Japan and New York City and Los Angeles in the United States, which are all in the developed world, still have serious problems. The bottom line: Most cities could be compared to sick people!
http://www.sciencedaily.com/releases/20 ... 130414.htm
If true it must be making Gaia sick.