SHANGHAI, China (AP) - President Clinton is delivering an environmental warning as he leaves the gleaming skyscrapers of Shanghai for the fabled limestone mountains of Guilin: China soon will have the ''unfortunate distinction'' of replacing the United States as the world's No. 1 producer of greenhouse gases.

While the problems are enormous, attitudes are changing, and Clinton pledged U.S. support for China's efforts to cleanup its environment.

He said yesterday that a major legacy of his visit will be U.S.-Chinese cooperation on the environment - something that ''ten years from now people will look back and say that's one of the biggest things they did.''

In a speech to American business leaders, Clinton urged China to cleanup corruption, open trade markets and combat the environmental catastrophe hanging over the world's most populous country. He said it was wrong to believe ''that there is an iron, unbreakable link between economic growth and industrial-age energy practices. ... It is simply not true.''

The president was accorded a third opportunity of national media exposure in a taped interview with state television CCTV. He was asked friendly questions and sidestepped on whether he or President Jiang Zemin has a tougher job.

With the end of the Cold War, Clinton said, ''America has this role which is temporary - it won't last forever - as the only superpower in the world.'' He said the world ''needs a leader, but not in the sense of one country telling everyone else what to do.''

Clinton's stop today in Guilin puts him amid the splendor of cloud-shrouded mountains and winding rivers that have inspired artists for thousands of years, a contrast to the high-rise modern structures of Shanghai.

After floods along the Li River, the government sent in 5,000 soldiers to clean up the mud-coated banks. The troops hauled away 20 tons of drift and sludge to improve things for Clinton.

China's devastating environmental problems have been a recurring theme on Clinton's trip, from his university speech Sunday to yesterday's address to American businessmen.

Reciting a dreary litany, Clinton said, ''Respiratory illness from air pollution is now China's No. 1 health problem. Every major body of water is polluted. The water table is dropping all over the country. China is about to assume the unfortunate distinction of replacing the United States as the largest emitter of greenhouse gases that are dangerously warming our plant.''

If that weren't enough, five of the 10 most polluted cities in the world are in China.

In Guilin, Clinton was launching a series of exchanges between U.S. and Chinese experts on global climate change. Also being spotlighted was U.S. assistance for a nationwide air quality monitoring network in China and a $50 million Export-Import Bank loan for clean energy projects.

China has pledged a $54 billion investment in the environment between 1996 and 2000 and is seeking foreign technology and investment to combat the problem.

Beijing, along with other major cities, has banned leaded gas, tightened emissions tests and ordered that all new cars beginning next year be fitted with catalytic converters.

The president, at breakfast with U.S. business leaders in Shanghai, expressed disappointment that he and Jiang failed to reach agreement on lowering trade barriers and other economic reforms, conditions that must be met before China gains entry into the World Trade Organization.

''But we'll keep working at it until we reach a commercially viable agreement,'' he said.

He said he couldn't ask China to slow its economic growth with strict anti-pollution measures. ''But as a citizen of the world and the leader of my country, I have a responsibility to ask us all to work together for a planet that our grandchildren can still enjoy living on. And so do you.''

Clinton and his family concluded the day with a leisurely boat trip down the city's main river, the Huangpu.