BALI, Indonesia - China insisted yesterday that the United States and other wealthy nations should bear the burden of curbing global warming, saying the problem was created by their lavish way of life. It rejected mandatory emission cuts for its own developing industries.

Environmental activists, meanwhile, labeled the United States and Saudi Arabia the worst "climate sinners," accusing them of having inadequate policies for climate problems while letting greenhouse-gas emissions increase. But the activists also said no country was doing enough.

Su Wei, a top climate expert for China's government attending the U.N. Climate Change Conference, said the job belonged to the wealthy. He said it was unfair to ask developing nations to accept binding emissions cuts and other restrictions being pushed for already industrialized states.

The United States and other industrial nations have long sent these gases into the atmosphere, while newly emerging economies have done so for only a few decades.

"China is in the process of industrialization, and there is a need for economic growth to meet the basic needs of the people and fight against poverty," Su said.

While many experts believe China has surpassed the United States as the world's top emitter of carbon dioxide and other heat-trapping gases, Su noted the Chinese population was far bigger and said America's emissions per person were six times higher than China's.

"I think there is much room for the United States to think whether it's possible to change [its] lifestyle and consumption patterns in order to contribute to the protection of the global climate," he said.

China is one of nearly 190 nations participating in the Dec. 3-14 conference, which is intended to launch negotiations on a new climate treaty to replace the 1997 Kyoto Protocol when it expires in 2012.

The Kyoto pact, which was rejected by the United States, commits three dozen industrial countries that signed on to cut emissions an average of 5 percent below 1990 levels over the next five years. One of the factors that led President Bush to reject Kyoto was that it didn't require any cuts by fast-developing countries such as China, India and Brazil.

Beijing was long accused by environmentalists of evading the issue of global warming, but was drawing praise for a new attitude at Bali, even though China was still relying heavily on dirty, outdated coal-burning techniques and was home to 20 of the world's 30 most polluted cities.

The environmental watchdog Germanwatch said yesterday that China moved up four spots, to No. 40, on its annual ranking of climate performance of 56 industrialized and emerging countries.

Germanwatch said Beijing has enacted policies promoting renewable energy, including mandates that solar, wind and hydroelectric systems provide 10 percent of China's power by 2010. It also ordered key industries to reduce energy consumption 20 percent.

Saudi Arabia was listed as last among the 56 nations, right below the United States.

The group said Saudi Arabia, the world's largest oil exporter, was the biggest "climate sinner" for the second year in a row because its emissions were increasing and it has no firm policies to address that.

The United States was ranked No. 55 because it opposed mandatory cuts in emissions and argued that technology, private investment, and economic growth would save the planet from global warming.

Australia was listed as third-worst offender, but with a caveat: It could rise to No. 20 if new Prime Minister Kevin Rudd follows through with promises to reduce emissions after signing the Kyoto Protocol last week.

Sweden was ranked as doing the best job, followed by Germany, Iceland and Mexico. Environmentalists said European nations as a group had progressed the most.