Peter Madden, chief executive of Forum for the Future, writes a monthly column for Gristmill on sustainability in the U.K. and Europe.

Forum for the Future recently asked a selection of top business and branding folk to give us the lowdown on the recent trend toward sustainable business. The gurus included Rita Clifton of Interbrand, Stuart Hart of Cornell University, William Kramer of the World Resources Institute, and Jonathon Porritt of Forum for the Future. I have distilled their wisdom into six insights.

1. A real sea change is underway. Looking at the current trends and recent announcements, there are signs of real progress and positive signals of change. In an arena that was once confined to the Body Shop and hippies, we’re now seeing a major shift in more mainstream businesses. In the U.K., Tesco, Marks & Spencer and Topshop are all in on the act.

2. Progress is partial. Despite the advances, the size of the challenges we face in building a sustainable future means there is still a long way to go. Even the more progressive strategies, such as General Electric’s “Ecomagination,” do not fully acknowledge — or live up to — the scale of change required. Fundamental questions regarding unsustainable business models need to be addressed before strategies can be fully credible.

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3. Business is in the driving seat, not consumers. Although consumer interest is increasing, it’s not yet strong enough to drive these trends on its own or make up the entire business case. Business strategy can’t completely rely on consumer insight or market research. Bold action and leadership is needed from business to drive this change through to the consumer.

4. There’s a green opportunity agenda. Numerous recent high-profile cases link sustainability more to the opportunity agenda of business growth and new market development, rather than the traditional territory of risk, reputation, and compliance. Marks & Spencer’s Plan A and GE’s Ecomagination are the strongest examples of companies doing this.

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5. We need a new marketing ethic. Sustainable business practices will require new approaches to marketing. Our gurus commented, for instance, on the perception that agencies lack awareness and need to shift to see more CSR people being involved in strategic marketing and planning. Some felt that more fundamental changes will require a more ideological and strategic shift — such as the rise of a new marketing ethic. (See the recent — and very good — The Green Marketing Manifesto for more on this.)

6. Delivery and performance is everything. Sustainable business needs to be built on real actions, activities, and results. The most convincing examples of sustainable business are built on tangible improvements, product or service performance, and delivery. Consumers are increasingly savvy about greenwash, and companies making environmental claims will face intense public scrutiny. Green products and services also have to match their competitors, or be better.

Overall, General Electric and M&S were the most mentioned by our gurus for best practice and leadership. They also suggested that HSBC and Unilever are the ones to watch. Wal-Mart and Tesco were frequently mentioned, though opinions were split on the green reality of the agenda, and some asked for more evidence of real results. People agreed, however, that they certainly have the big business buying power potential to really make a difference.

Our green gurus concluded that a sea change is happening — they saw a real shift in business awareness, attitude, and buy-in to the green agenda. Are they right?