When Scott Settelmyer describes his company, TerraCarbon LLC, it's easy to describe the potential. "I think it's an interesting field, and really it could be pretty big," Settelmyer said. "They're saying this could become a $2 trillion market (annually). Now it's $64 billion, according to the World Bank. This could be the biggest commodity market worldwide." What isn't nearly so simple is explaining how it all works. TerraCarbon specializes in carbon trading, which despite its rapidly emerging international market is a field unknown to most people. Client Carol Jordan, president of Atlanta-based Environmental Synergy Inc., describes it this way: "Whenever anybody asks what I do, I always take a deep breath." Carbon footprint Settelmyer, 39, took a winding road to the carbon field. His dad, Harry, is a stockbroker. By age 9, Settelmyer's paper route in Peoria provided money to invest in stocks. "I literally would get my papers at the corner in the morning, and by the street light I was holding up the paper and checking the ticker to see if I made money on those stocks," Settelmyer said. "It was something I really connected with." Settelmyer left Peoria for 20 years after finishing high school at Spalding in 1986. He earned a bachelor's degree in finance from the University of Illinois and a master's in financial markets and trading from Illinois Institute of Technology. He also is a certified public accountant and a charter financi ...