A couple of years after former Sierra Club President Adam Werbach founded  ActNow, a sustainable business consultancy, he signed up Walmart as a client. This brought Werbach considerable notoriety in eco-activist circles. Walmart’s record of environmental responsibility had previously been spotty, to put it mildly. Werbach retorted to his critics that Walmart, with almost two million employees and 127 million customer visits per week, had the potential to do far more to save the world than the Sierra Club ever had.

I had the opportunity to visit Werbach’s company (now named Saatchi S) in San Francisco, and attend a staff meeting. The participants sat on the floor and passed around a plate of organic banana bread. Yet despite the trappings of informality, the conversation had a focus, drive and ingenuity about it that I had rarely experienced in the non-profit world.  The Saatchi staff certainly looked like the young, idealistic types whom I knew from environmental NGOs. But dropping a profit incentive into the motivational mix seemed to release a different level of creative zing.

Subsequent encounters with other leaders of cutting edge green companies strengthened this sense of the potency in marrying idealism with the scale and dynamism of the business world. Jonathan Rose, CEO of a large US sustainable urban development consultancy, Arnold Goldman founder of Brightsource Energy and Yosef Abramowitz of the Arava Power Company all combine strong ethical vision with a rigorous ambition to build successful businesses that will help solve large, real-world challenges.

Two valuable recent books have helped expand and sharpen my understanding of the potential for green business to do good while doing well – and also its limitations.