"The upgrading signifies the importance of the environmental agenda," he says. "The changes took place step by step, and they are continuing."
Dudek, who pays close attention to environmental news about China, says he has observed a growing awareness of the environment among average Chinese.
"People are much more concerned about environmental problems (these days), they are more vocal, which raises government's expectations to solve these problems," says Dudek, adding that part of the changes come along with technology, including the air-quality monitoring apps on smartphones.
But Dudek points out that it is a big challenge to achieve satisfying results for environmental protection in such a huge and diverse country, where great differences between regions exist.
"It's still a challenge to have people understand that we really need broad cooperation to solve the problem because of the difference between physical boundaries (among provinces and regions)," he says, adding that he once in a while finds it difficult to promote his ideas among regional officials.
In the U.S., he says people faced similar challenges, but in the end they succeeded, thanks to such programs.
China plans to launch a national emission trading system in 2017, part of a joint presidential statement issued by China and the United States in September 2015.
Dudek hopes it can finally break down the traditional mindset of competition between regions and help them communicate better.
Dudek stresses it's no longer enough for the government to just give out regulations, and it's important to design policies that will create incentives so that enterprises learn to respect the environment more.
"To make right things easy and wrong things hard - that's the way to achieve leverage," he says.
In 2007, he was appointed as one of the 23 members of China Council for International Cooperation on Environment and Development, an advisory body to the Chinese government on the environment and sustainable development issues.
Recognized for his work in China, Dudek was awarded the Friendship Award, the highest honor given by the Chinese government to foreigners for their contributions in social and economic development, in 2004.
"For me it is a kind of recognition, not of me personally, but of such ideas. It's a kind of validation that it is something important for China's future," says Dudek, who thinks himself as a representative of all the people making the same efforts.
According to Dudek, his long-term commitment to China naturally has extended to his family.
He and his wife have adopted two Chinese girls from East China's Jiangsu province. Nowadays, the family regularly has Chinese guests at home. The couple also tries to keep their children aware of Chinese culture and events in the country.
"China in some sense is my second home," he says.
"My experience here has been for most of the period of reform and opening-up. It is one of the most important parts of Chinese history. And, to be able to participate in it has been spectacular."
