BEIJING - Some modern farming techniques once thought successful in boosting production instead have caused ecological damage too expensive to repair, says an American environmental expert.

John Cobb, a long-time researcher on ecological sustainability, told Xinhua recently that modern farming, with its sole focus on raising output and featuring excessive use of petroleum and chemicals, has inflicted irreversible damage on the environment.

Industrializing agriculture has been one of the biggest mistakes made in the United States, Cobb said, adding that its implementation has effectively increased the loss of topsoil and the depletion of water resources while making the sector heavily dependent on oil.

In addition, Cobb said, the monocrop system now used for mass production has also played a role in creating ecological problems such as a dramatic drop in bee and bird populations.

"In the United States, the policies are dictated by Wall Street and the financial leaders are the most powerful people in the country," Cobb said. "But they have very limited vision for the long term and they are much more interested in short-term profits."

Like the United States, Cobb said, many other countries have achieved economic success at the price of ecological destruction.

It is already too late for many of the developed nations to reverse the ecological degradation they have caused in pursuit of economic gains but the late-comers to modernization have a better chance of dealing with the problems, Cobb said.

China, which has astounded the world with rapid economic development in the past three decades, should devote more attention to establishing an ecologically responsible growth pattern, Cobb said.

He said he was happy that the Chinese government started to build an ecological civilization years ago and recently has stepped up efforts to steer the national economy toward greener development.

However, he warned that the pride many Chinese have in their national economic achievements might be a liability to the country's so-called green efforts.

Cobb urged policy makers around the world not to simply see agriculture as a source of food but as a complicated system that is key to the welfare of future generations.