2.1 Specification of the environmental and economic aspects
Given the wide scope of interpretation of the concept of sustainability and its development, it is obvious that there are a variety of approaches to its specification. Equally obvious is that scientific and ecological concepts for instructions as the basis of these concepts must be agreed with their economic "management". It is thus targeted to dealing in production and consumption of renewable and non-renewable natural resources and other features that are found on the ecosphere for the economic system. "Such features are the inclusion or assimilation of material inputs, they are in securing general ecosystem functions as well as the direct influence of human well-being. In summary, it iss poken of the ‚natural capital ', which is separated from ‚man made capital‘ created by people. Sustainability concepts now differ greatly in assessing how far the substitution of natural capital is possible by physical capital.“
There are basically two approaches which have to be distinguished:
1. the optimistic view of the "weak" sustainability, by which for almost all functions of natural capital replacement by other types of capital should be possible. This replacement or substitution processes should be permitted if the existing capital will be wholy preserved in this way;
2. the "pessimistic" approach provides critizises such substitutability and does not see it as given. This concept of "strong" sustainability argues that intergenerational justice requires that "the stocks of different types of capital remain independent of each other in biological or physical standards. This is especially true for natural capital. As an argument for it is argued that the natural capital and physical capital are usually complementary in production and consumption ratios (for example, fishing boats without fish are without any sense). "For a position of strong sustainability would thus follow to preserve each component and subsystem in its physical inventory. However, this seems impossible, especially because incessantly changes take place within the ecological system.
The more plausible concept of strong sustainability has developed for practical implementation as a guide to action three management rules that will improve the natural capital stock permanently. These management rules are both macro and micro applicable as well as at the l political and social level. They include the principles that
1. the degradation rate for renewable natural resources should not exceed their regeneration rate. In this way, in principle, the ecological performance of this part of the natural capital should be maintained. But even here there are many imponderables that must be observed for each concrete implementation, and allow infinitely many solutions.
2. substances into an environment can be controlled permitted only to the extent, that they correspond to its assimilation ability and can cause any danger of its functions (critical loads, critical levels). "It should be noted that the form of the use of natural resources due to the first law of thermodynamics, the mass and energy conservation law, eventually determines at the same time the amount of material inputs in the ecological system."
3. Because of the second law of thermodynamics, the entropy law, any use of non-renewable resources reduces, in the final analysis, the available stock. Therefore, for this one "is required quasi-sustainable use“. „Non-renewable resources should be used only in the extent to which a physically and functionally equivalent replacement is assured in the form of renewable resources or a higher productivity of natural resources in their use." And if exhaustible resources are used, then is has to be distinguished between two parts: Although a proportion of their output can be used at the same time but the other part is to be inserted in the construction of renewable resources to compensate for their consumption. The result then is to serve the newly established renewable resource to replace the consumed. In this way a continuous consumption stream could be ensured. Provided here is that technical efficiency is increased accordingly and so contributes to the quasi-sustainable use.
Both in the Brundtland report as in Agenda 21 indicators were early called for that would be suitable as a benchmark for sustainable development. This is true even for the political dimension, for which the State must provide at the local, regional, national and international level. In practice, this means that the gross domestic product has to be mapped faithfully and environmental damage and repairs must be considered (Ökosozialprodukt / Genuine Progress Indicator as a further development of the Index of Sustainable Economic Welfare). Therefore, it was also already a work program submitted in the work of the UN Commission on Sustainable Development in 1995, where in cooperation with the UN Department for Policy Coordination and Sustainable Development (UN DPCSD) a list of more than 140 indicators will be developed. These are firstly divided into four categories: economic, ecological, social and institutional indicators; on the other hand, grouped by the Pressure-State-Response principle (PSR), the CSD chooses instead pressure the wider approach of the driving force. This would result in a matrix, which meets the requirements of Agenda 21 and can be applied at national level.
However, this process is not yet complete and the question is whether the development of indicators can ever succeed in the sense that a realistic figure may be held by indicators. This also because interpretational factors play a major role.
At this point the critical question arises whether the above-mentioned objectives of sustainable resource use have been achieved so far in any direction. This can be relatively "easy" measured by the two criteria, whether
1. the "ecological footprint" has been reduced and whether
2. for each person quality of life has increased. Thus, in 2012 on August 22, the entire stock of natural resources has been consumed, which has been produced on Earth throughout 2012. This means that from that date the generated amounts of waste and emissions could not be absorbed (so called Earth Overshoot Day). This date occurs every year a little earlier. "After four decades of Planet Earth Politics controls the planet still steers to the collapse the Club of Rome predicted for the middle of the 21st century."
Also, to improve the quality of life as a promise of the good life for all, it has not become better. Apart from the increase in the quantitative growth (gross domestic product) and the associated accumulation of goods, no reliable quality of life for everyone is generally considered obviously occurred, as it is the goal of a sustainable lifestyle and economy. For this argument the well-known studies of the WHO and the FAO from all the past years and decades can be used as evidence. This critical interim conclusion nevertheless should not devalue the variety of measures, which were part of the policy at local, regional, national and international level, or of companies and have been since enforced; nor the measures in consumptive area. On the contrary: Without it, the sustainability balance sheet would look absolutely devastating.
