Change is recognized as being intrinsic to ecosystems, but is also the essence of instability and the outgrowth of situations that lack sustainability. Change is arguably the most fundamental symptom for onset of abnormality in ecosystem function, and change in change cannot be detected without sufficient monitoring to determine spatial and temporal aspects of characteristic change regimes across landscapes. It must also be recognized that change can be associated with either restoration or degradation. A suite of recent developments in change detection using compressed multiband image data provides increased flexibility and practicality for systematic change detection on a regional basis. Combining such capability with conceptual extensions of spatial pattern analysis through echelons can provide a methodology for systematically monitoring spatial structure of spectral change across landscapes in order to profile characteristic broad scale regimes of change and to indicate trends in those regimes. Implementing these analytical scenarios with new generations of computers and remote sensors could lend a further dimension to tracking of ecosystem status over major regions.

Most insights of environmental economics are in line with the standard neoclassical economic model of rational behaviour, formulated in terms of maximization of utility in general, or profits in particular. The standard theory of environmental policy is a case in point. However, the maximization hypothesis and its methodological foundation have been criticized on many grounds, related to a lack of either logical or empirical content. Moreover, over the years a great many alternative models of behaviour have been proposed. Both criticism and alternatives are surveyed here. In the context of environmental economics behavioural assumptions have been most significant for the development of economic valuation theory and environmental policy theory. The focus here will be on environmental policy theory. 1.

Living systems are nested and consist of basic materials, cells, organisms, ecosystems, and their environments, continuously interacting in time and space. Life is an integrated process of nested living systems. We synthesise and discuss exergy capturing and accumulation of organisational exergy; the structuring of the system towards maximum entropy production and export of high entropy products; autopoiesis; emergent attractors or optimum operating points; characteristics of nested systems and holarcic levels; and the role of working and latent information. It is concluded that it is only possible to describe the livingness of a system in a continuous way, and that living matter should be defined by the processes of which it is a part. Hence, from the perspective of selforganising and nested living systems it is difficult to draw boundaries between living and non-living as well as human and non-human systems. Implications of this worldview is discussed in relation to environmental management.

Some economists have advocated the use of measures of genetic dissimilarity to guide species preservation priorities. It is argued here that such policies are: i) possible for only a very small number of species for which data are available; ii) impractical as a general guide to biodiversity preservation for that reason and because it is impossible, given the present state of knowledge, to account for species interdependence; and, critically, iii) misguided because, at least over the relatively small species sets for which data exist, there are generally no established or theoretically convincing relationships between genetic dissimilarity and species value. Keywords: biodiversity; genetic diversity; inherent value; option value; ecosystem services. JEL Classificaton: Q21; Q28 Acknowledgements I should like to thank Charles Perrings, Tony Ivens, James Maw and Martin Weitzman for comments on the first draft. It hardly needs saying that they do not necessarily agree with the views expre...

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The globalization of most industrial operations has led to a high degree of disconnect between the consumers and the goods and services they consume. The connections between the manufactured products and the culture and place from which they originate and their place of consumption are often lost. This leads to accelerating environmental degradation and decreased quality of life for many people. The engineering community is partly responsible for this situation, due to their lack of consideration of the ecological and social consequences of design in a comprehensive manner by taking into account the rich contexts in which goods and services are produced and consumed. Adaptation and incorporation of ideas from ecological design and the development of appropriate curricula have the potential to change this situation significantly. In this paper, I describe an approach to accomplish these objectives.

With this SNE double issue, SNE 18/3-4, our journal SNE is on publication schedule again, after delays in publishing of regular issues, caused by some changes in strategy and changes within the EUROSIM simulation societies. At present we are working on the last changes in publication strategy, driven by a new web page with new functionalities (layout see picture). This new webpage not only will document SNE and its contents, but also it will organise the SNE administration in submission, reviewing, publishing, and distributing contributions, and it will allow to evaluate the ARGESIM benchmarks. Authors may submit contributions of any kind via this system, followed by an appropriate reviewing. Also reports from societies will be managed by this system, so that new SNE issues can be compiled in time on basis of reviewed and refined contributions. We will report in detail about this new system in the first issue of 2009, SNE 19/1. The Technical Notes, Short Notes and Benchmarks Solutions in this issue on the one side set an emphasis on hybrid modelling and simulation by contributions on hybrid bond graphs (I. Roychoudhury, G. Biswas), on comparison of hybrid features in simulator (N. Popper et al.), on multi-paradigm language engineering (H. Vangheluwe), and by hybrid approaches to benchmark solutions. On the other side, discrete modelling and simulation plays a major role, by contributions on LAN modelling and monitoring (M. Nazri et al), on discrete event modelling in facility management (D. Wiegand et al.), and by two solutions to the ARGESIM benchmark ‘Restaurant Business Dynamics’. Two contributions deal with methodological aspects: functionality of a specific validation tool (P. Kemper), and an approach to the precise modelling of essential terms (J. R. Müller). Furthermore we are proud to publish an interesting contribution by the H. Fuss, a doyen among Petri net

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Abstract: The results of economic models of greenhouse gas reduction depend sensitively on the assumptions embedded in the energy scenarios chosen, both for business-as-usual and emission reduction scenarios. In this paper, some of the basic requirements of useful scientific models are reviewed and then, as a case study, applied to the MEGABARE computer model of greenhouse response in the global economy. At the Conference of the Parties to the Framework Convention on Climate Change, held in Kyoto, Japan, in December 1997, the Australian Government used MEGABARE as a basis for its successful demand that Australia, as a fossil fuel ‘dependent ’ country, should be permitted to increase its greenhouse gas emissions. However, it is shown here that several of MEGABARE’s basic assumptions fail to meet basic criteria for useful modelling. Two alternative, low-cost, emissions reduction scenarios for Australia, which contain fewer ad hoc assumptions than MEGABARE, are presented: 1 A ‘moderate ’ reduction scenario that is equivalent to the pre-Kyoto

... This report demonstrates that both the government and the private sector are moving ahead rapidly to develop and implement sustainable practices for facilities and the activities that take place within them. It identifies opportunities for the Corps of Engineers to be a major national source of expertise that carries the knowledge of what sustainability is, into engineering practice. The approach for accomplishing the practical realization of sustainable engineering is to develop engineering tools that capture rapidly developing knowledge about sustainable practices that spans all phases of a facility life cycle. The facility life cycle phases encompass planning, design, construction, commissioning, operation and maintenance, rehabilitation, re-use, and disposal