Administrative divisions of China By its political level, when a "city" is referred to, it can be a: By its actual area and population, it can be: When used in the statistical data, the word "city" may have three different meanings: It is important to specify the definition of "city" when referring to statistical data of Chinese cities, otherwise, confusion may arise. For example, Shanghai is the largest city in China by population in the urban area but is smaller than Chongqing by the population within the administration area. Before the establishment of the Qin Dynasty, China was ruled by a network of kings,
Environment of China China. China has a diverse flora, with more than 30,000 plant species native to the country. The position of the Chinese government on climate change is contentious. China is the world's current largest emitter of carbon dioxide although not the cumulative largest. China has ratified the Kyoto Protocol, but as a non-Annex I country is not required to limit greenhouse gas emissions under terms of the agreement. There are several forms of protected areas in China. Each type of protected area is protected on either a national, provincial, or county level. Rapid industrialization, population growth, and lax environmental oversight have