I am on the board of corporations who contribute both to environmental problems and their solutions. And I am on the NGO side: the Earth Council and other organizations.

What pleases me most is that sustainable development is on almost everybody's agenda now.

A citizen of an advanced industrialized nation consumes in six months the energy and raw materials that have to last the citizen of a developing country his entire lifetime.

After all, sustainability means running the global environment - Earth Inc. - like a corporation: with depreciation, amortization and maintenance accounts. In other words, keeping the asset whole, rather than undermining your natural capital.

I learn something from criticism because when it comes from sources you respect you always examine it and learn.

Nevertheless, the concept of sustainable development is now known - even amongst those who haven't accepted it - and it's recognized, debated and followed by an increasing number of businesses.

One of the things that Ive always thought I would like to do is to develop an environmental index. Then people can measure their own environmental performance on an index as they do in other ways.