An environment education program at a Nanjing community in 2009. [Photo provided to China Daily]

"The acid rain was extremely bad, causing the acidification of the lakes, damaging forests, and our neighbors in Canada were very unhappy with us," recalls Dudek. He then became interested in solving the problem using a financial approach.

In 1985, Dudek had the opportunity to join the EDF, which was looking for someone to work on economic incentives to control atmospheric pollution.

"I thought this was the chance to take the ideas in the textbook and put them into reality," he says.

Since then, he has been working to put the concept of "cap and trade" into practice. This approach limits the overall amount of pollution produced by factories while allowing the emitters to save or trade their excess quotas of emission to those unable to meet the required standard. The result: Both groups are motivated by profits to reduce their pollution impact.

Dudek's work contributed to the Clean Air Act Amendments of 1990, under which the first emission-trading program in the US, was set up. Dudek and his team were praised by President George H.W. Bush for breaking the logjam on acid rain.