The rich arable land along the coastal plain is rapidly being covered with homes, factories, roads, and parking lots, while soil erosion has reduced the productivity of a sizable portion of the remaining lands. Moreover, demand for building materials and firewood has put similar pressures on China's forests. International surveys find that five of the world's ten most air-polluted cities are found in China. China's acid rain is also carried by the wind to Japan and South Korea, both of which claim that China now accounts for more than half the acid rain falling within their borders. Globally, China's rising emissions of greenhouse gases have placed it at the center of international debates over climate change.
China is already the second largest producer of carbon dioxide, the leading greenhouse gas.
Though its per capita emissions are currently one seventh those of the United States, future growth is projected to push its overall emissions past the US by 2020. The Framework Convention on Climate Change, signed in 1992, calls for industrial countries to hold greenhouse gas emissions in the year 2000 to 1990 levels, but includes no limits on developing countries. As attention now turns to a new protocol to the convention to be adopted at the Third Conference of the Parties in Kyoto in 1997, however, pressure is building to slow the rapid growth in emissions now under way in China and in other developing countries. Unless China soon begins to follow a new energy path, even the most aggressive efforts by industrial countries to reduce their emissions will eventually be overwhelmed. Global climate change could also exacerbate the already serious water shortages that plague northern China, reducing food self sufficiency in the process.