Since economic reforms began in the late 1970's, China's push to become a major industrial power has put a tremendous strain on its environment. Pollution-related problems, from acid rain to contaminated rivers, are now commonplace in China. Authorities in Beijing have taken measures to try to improve environmental protection, but as Naomi Martig reports from Hong Kong, most analysts agree they are not enough.

On a severely polluted day in many Chinese cities, it is difficult to see beyond a few hundred meters. In northern China, drought has left more than two million people without enough drinking water, partly because much of the area's remaining water supply is contaminated by pollutants. And in cities such as Guangzhou in southern China, authorities have been trying to clean up the air for more than a decade.

Air and water pollution in China have reached alarming levels in recent years. Despite having some of the world's largest water reserves, two-thirds of Chinese cities have less water than they need because of overuse and pollution. Many experts say China will soon pass the United States as the world's largest producer of carbon dioxide.

Lo Szeping is the Campaign Director for Greenpeace in Beijing. He says government figures show more than half of China's rivers and lakes are polluted, and air pollution is just as bad.

"According to the World Bank, 17 of 20 of the world's most polluted cities in terms of air quality are in China," he said.

In addition, the country's growing population is contributing to China's pollution problems. Leiwen Jiang is a professor of international and environmental studies at Brown University in the United States. He says China's population is not increasing at an alarming rate, but it is still cause for concern.

"Population growth and the increase in consumption will inevitably generate heavier pressure on the environment and natural resources," he said.

Water reserves, for example, are unevenly distributed with northern China much drier than the south. However, the north still has to cope with a growing population - which means less water per person.

Authorities in Beijing have taken steps to try to improve conditions. The central government has shut down hundreds of polluting factories and put fines in place for companies that do not abide by environmental regulations. But for experts like Paul Harris, an environmental studies professor at Lingnan University in Hong Kong, those efforts have largely failed.

"At the local and regional and provincial level, the level of corruption and the desire for, to benefit from profit and industrialization is still much too powerful," he said. "Beijing has very little influence at the local level in this particular view."

Harris says many factories would rather pay a fine than follow more costly environmental standards. He believes that only when pollution problems begin to hurt regional economic growth, will local officials enforce environmental regulations.

In the meantime, experts are concerned that the health effects of an increasingly polluted community will soon become a political challenge for the central government.

Social unrest is already emerging around China. People living near polluting factories are protesting the contamination of land and water supplies. Professor Harris says he believes such movements will increase as steadily as China's pollution problems.

"The government is going to have trouble dealing with the protests and the like associated with this," he said. "So I'm suggesting that the Chinese Communist Party and the government more broadly may find that their survival, their hold on power, is at stake because of environmental changes."

Environmental activists say if authorities in Beijing want to maintain social stability, and continue economic growth, they are going to have to tighten regulations and employ cleaner technology.