Paul Hawken is a best selling author of several green commerce books. The Ecology of Commerce (Collins Business, 1993), Natural Capitalism (Little, Brown and Company, 1999), and Blessed Unrest (Penguin Books, 2007).
These three books plus a few others he has written or co-authored have been hailed as some of the most insightful, provocative, and visionary ideas on eco business. Hawken's is a world-renowned environmentalist, small business owner, and highly respected author.
In the book Natural Capitalism, Hawken's presents a fourth type of capital that businesses need to aware of in order to be successful and to be environmentally acurate. The three commonly known capital includes human capital (employees, intelligence), financial capital (cash, investments), manufactured capital (infrastructure, machines, tools, and factories), and the fourth is natural capital (resources, living systems, and ecosystem services).
I've read parts of all three of the books mentioned above. Hawken's is insightful and provides theories and solutions that can easily be recognized as having been thought through to the last detail.
If any business owner, manager, supervisor, or anyone having an interest in learning true environmental theory that can be put into practice, these three books make for a great place to start.