The word -generation’ emphasises the evolutionary nature of the complexity and depth of environmental strategies and the eco-indicators that result from them. Because companies are facing new challenges in relation to sustainability they will need new strategies and new eco-indicators. TNO-Institute for Strategy, Technology and Policy is working on a methodology to develop these new eco-indicators. This paper elaborates on the results of a literature study, our experience in the field of strategic management and several other projects we have carried out on this subject.

The three key questions discussed in this paper are:
Ã?? What are the characteristics of the fourth generation of environmental strategies?
Ã?? What kind of eco-indicators will be suitable for the new challenge?
Ã?? How can these new indicators be developed?