*3.1.5. Alternative thinking about sustainability*

An alternative model for sustainable development within a "sustainable hierarchy" has been presented [8]. This focuses on unsustainable activities which should be avoided and lists the most serious problems at the bottom. Level 1 actions endanger the survival of humans, Level 2 actions significantly reduce health and life expectancy, and Level 3 actions may cause species extinctions or violate human rights. The fourth and last level contains actions that reduce quality of life or are inconsistent with other values, beliefs or aesthetic preferences. The authors argued that this level should not be considered to be within the sustainability concept, since these topics to a high degree depend on subjective criteria. As shown in chapter 3.4., this viewpoint is not shared by the present writer.

Twenty years after the Brundtland Commission, it was suggested to "reopen" the concept of sustainable development [9]. This paper relies heavily upon a science-based approach to sustainability known as "The Natural Step Framework" after the organisation promoting it. They focus on the way we extract resources, use them and produce wastes, but also on other ways in which we destroy nature's carrying capacity. In a nutshell, nature should not be subject to systematically increasing…


Regarding "economic ethics", the article stresses that "hidden costs of unsustainability" must be shown, and no economy should exceed nature's carrying capacity [9].

Another thorough review [7] was critical to economic growth and pointed out various misuses of the sustainability concept. Still, they saw a hope for a further "creative global dialogue". In fact, since sustainable development is an imprecise concept – but still with intuitive aims – it contains a "creative tension", and the debate is still active. Sustainable development can be viewed as a social movement: a group of people with a common ideology who try together to achieve certain general goals. The authors point, for instance, to the vision of "voluntary simplicity" and a need to define life quality by other criteria than by economy and consump‐ tion. Today, it has been a serious matter to explore various indexes of "well-being" or "level of happiness", see [13].

#### *3.1.6. Perspective*

We can conclude that during the twenty-five years since 1987, the vague vision of the Brundt‐ land Commission has undergone a considerable conceptual refinement. Although we find different "schools" that vary in their way of thinking, they all strive to enlighten the way into a harmonious future. Ecosystem thinking has become a fruitful common approach, illustrating ecological services and nature's vulnerability to overconsumption. A further conceptual development will certainly occur, both in order to clarify ideals and principles, to describe conflicts, and to implement concensuses in law and in personal lifestyle.

There is a special need to clarify the conflict between environmental and economic sustaina‐ bility. Even in 2012, world leaders include economic growth in the concept of "green econo‐ my". This concept is accepted and could be fruitful, but is unsustainable until it is defined as a sub-system which is in harmony with the biophysical limits of ecosystems. Also, what are the guidelines for an "economic ethic" that implies a moral aspect in addition to income? Economic thinkers have a challenging task, and interdisciplinary research is needed to describe a sustainable "green economy".

#### **3.2. The rise of applied ecological thinking: From basic science to politics**

This topic has already been mentioned when discussing environmental sustainability but here, the use of ecological thinking will be followed in a more chronological way.
