China's environmental problems are among the most serious of any country in the world, and they are mostly getting worse.

That's one conclusion from a recent article in the journal Nature co-authored by Jianguo Liu, director of the Center for Systems Integration and Sustainability at Michigan State University.

Liu also believes China's environmental problems are partly our fault.

"Nowadays, it's rare that someone doesn't buy products produced in China," Liu said. "You import the product, but the air pollution and water pollution ... is left behind."

Liu isn't saying that the rest of the world should stop buying Chinese products. He is saying that people should be conscious of the serious environmental situation in the world's most populous country and of its potential global impact.

Liu wrote the article, which appeared in the June 30 edition of Nature, with Jared Diamond, a professor at the University of California, Los Angeles, and the author of "Guns, Germs, and Steel: The Fates of Human Societies," a Pulitzer Prize-winning book published in 1997.

The two scientists reported that the frantic rate of economic growth in China, along with increases in the number of households, the continued use of outdated industrial technologies and China's role as a "world factory" have contributed to a bleak environmental outlook.

China now is facing environmental problems ranging from air pollution and biodiversity losses to trash accumulation and water shortages, Liu and Diamond wrote.

The country's per capita environmental impact remains low, though, with 1.3 billion people, the total impact still is substantial.

But if China were to adopt Western living standards, the world use of natural resources would double, they reported.

Liu said China's environment is a global problem.

"Air pollution in China will reach the U.S. within a week," he said. "That will cause damage to the U.S. environment and lower the economic efficiency in the U.S."

He's equally convinced that it's a problem that should be addressed, at least in part, on global levels.

That doesn't mean discouraging China's economic development. He and Diamond noted that, because China's per capita levels of consumption and pollution are lower than those of developed countries, "China has the moral right, as well as the power, to develop."

What Liu does recommend is helping China find a balance between economic development and environmental protection.

Technology transfer would be one way to do that, he said. The efficiency of resource use in China is much lower than in developed countries. Giving China access to more efficient production technologies would help reduce environmental impact.

Ruth Francis, a spokeswoman for Nature, called the paper "an excellent overview of China's environment" and interesting research "given the size and global importance of China, and the fact that its environment is relatively unknown outside China itself."

Liu said he and Diamond pursued the project because, while many smaller projects had been done on China's environment, there was no overall synthesis. And the effect China has on the rest of the world is only going to increase.

"China is the largest country," Liu said. "Everything that China does will have a big impact - not just in China, but on the world."