This article on Green Corporations gets into some of the issues about why it makes financial sense for a company to spend more initial dollars to prevent such catastrophes as Exxon Valdez and Bhopal, rather than spending dollars down the road to clean up mistakes. The greening process makes sense from a purely profit-driven motive, which is the motive of utmost importance to most corporations operating where the eyes of the world are on them. Situations like the deforesting of Papua New Guinea happen because the majority of people are ignorant of what's happening, and a rogue corporation can operate in relative obscurity and with fewer negative financial outcomes.