*3.1.2. Environmental sustainability*

The basic aim of environmental sustainability is to maintain healthy, productive, and species rich ecosystems. Such "supporting ecosystems" deliver "environmental services". They have a certain tolerance to disturbance, and a certain "carrying capacity" regarding production of goods as wildlife, fish, various forest products, clean water, fertile soil, etc. Healthy ecosystems also have a certain "assimilative capacity" for our pollution and wastes. Many prefer to use the concept of "natural capital" for nature's ability to serve us, and this capital has to be maintained. Furthermore, the term "sources" is often used for raw materials extracted from nature, and "sink" for wastes. A "sustainable production" and a "sustainable consumption" implies to live within the limitations of the biophysical environment, while "overconsump‐ tion" gradually liquidates nature's ability to deliver environmental services. Loss of nature also implies loss of other "services" like recreation, various cultural values, and nature as a source of fascinating science.

As long as nature was "in excess", nature's productivity and assimilative capacity was enormous compared to man's needs and activities. Today, healthy ecosystems have become a scarce resource, like intact forests, species-rich coral reefs, productive oceans, clean rivers, or fertile soils. During the last sixty years, ecological thinking and ecological concepts have become a cornerstone in defining the limits – but also the options – for man in a sustainable future. The conceptual development within the rise of applied ecological thinking is presented in chapter 3.2.

#### *3.1.3. Economic sustainability*

Since economic development is one of the primary drivers behind environmental degradation, economic activity should be kept within strong limits. For instance, to eradicate one resource after the other (e.g. whales, tropical forest, oil wells and fish stocks) may be good economics in terms of income, but totally unsustainable. Environmental costs have to be included in economic activity. A "sustainable economy" can be regarded as a human economy subsystem which does not harm the ecosystems and their ecological services on which we depend. Economics has rarely been concerned with natural capital, because until recently, these resources had not been scarce. The new scarcity of natural capital arose because the *scale* of the human economic subsystem had grown large relative to its supporting ecosystem. The "scale criterion" would constrain the so-called "throughput growth" – the flow of material and energy (natural capital) from environmental sources to sinks (pollution and waste), via the human economic subsystem. However, due to our limited knowledge about nature's resilience and the danger of irreversible damage to ecosystems and their services, economists need to use the precautionary principle routinely. Also in economics, ecological thinking and concepts have become relevant.

At the UN conference in Rio de Janeiro 2012 (Rio + 20), "green economy" was identified as a pivotal concept in order to create a sustainable development [10]. The intention was to define an economy which is positive for both environment, climate and poverty problems. However, economic growth is still a silent premise in the new "green economy". In Rio, both OECD, The World Bank, large companies and national leaders in several of the richest countries encour‐ aged further economic growth. This request was discussed and criticized in a Norwegian newspaper article [11]. For instance, the authors argued that the northern "brown oil economy" has to be changed into a green direction, which implies reduced overconsumption and more focus on intellectual resources. Furthermore, many ecological services cannot – and should not – be capitalized, as the optional value of biodiversity, nature's production of clean water, air and soil, or the recreational value for man. The article also presented the concept of "browngreen new colonialism", which was exemplified by the oil-nation Norway which pays for forest protection and climate quotas in the south, rather than on a national level within Norway.
