The controversy over carbon emissions is just one of several surrounding ExxonMobil -- a list that includes gasoline prices surging towards $4 a gallon the company’s push for expanded oil exploration and drilling and its high-profile war of wills with the president of Venezuela Hugo Chavez. Yet during a presentation as part of the Wharton Leadership Lecture series Donald D. Humphreys senior vice president and treasurer of the Irving Texas-based behemoth set out to erase what he said are widely held misconceptions about the powerful company that traces its roots back to the 19th century and John D. Rockefeller.