Review for ESS.pdf

An EVS is a worldview or paradigm that shapes the way an individual, or group of people, perceives and evaluates environmental issues, influenced by cultural, religious, economic and sociopolitical contexts. An EVS might be considered as a system in the sense that it may be influenced by educat...

An EVS is a worldview or paradigm that shapes the way an individual, or group of people, perceives and evaluates environmental issues, influenced by cultural, religious, economic and sociopolitical contexts. An EVS might be considered as a system in the sense that it may be influenced by education, experience, culture and media (inputs), and involves a set of interrelated premises, values and arguments that can generate consistent decisions and evaluations (outputs). There is a spectrum of EVSs, from ecocentric through anthropocentric to technocentric value systems. An ecocentric viewpoint integrates social, spiritual and environmental dimensions into a holistic ideal. It puts ecology and nature as central to humanity and emphasizes a less materialistic approach to life with greater self-sufficiency of societies. An ecocentric viewpoint prioritizes biorights, emphasizes the importance of education and encourages self-restraint in human behaviour. An anthropocentric viewpoint argues that humans must sustainably manage the global system. This might be through the use of taxes, environmental regulation and legislation. Debate would be encouraged to reach a consensual, pragmatic approach to solving environmental problems. A technocentric viewpoint argues that technological developments can provide solutions to environmental problems. This is a consequence of a largely optimistic view of the role humans can play in improving the lot of humanity. Scientific research is encouraged in order to form policies and to understand how systems can be controlled, manipulated or changed to solve resource depletion. A pro-growth agenda is deemed necessary for society’s improvement. There are extremes at either end of this spectrum (for example, deep ecologists–ecocentric to cornucopian–technocentric), but in practice, EVSs vary greatly depending on cultures and time periods, and they rarely fit simply or perfectly into any classification. Different EVSs ascribe different intrinsic value to components of the biosphere A systems approach is a way of visualizing a complex set of interactions which may be ecological or societal. These interactions produce the emergent properties of the system. The concept of a system can be applied at a range of scales. A system is comprised of storages and flows. The flows provide inputs and outputs of energy and matter. The flows are processes that may be either transfers (a change in location) or transformations (a change in the chemical nature, a change in state or a change in energy). In system diagrams, storages are usually represented as rectangular boxes and flows as arrows, with the direction of each arrow indicating the direction of each flow. The size of the boxes and the arrows may be representative of the size/magnitude of the storage or flow. An open system exchanges both energy and matter across its boundary while a closed system exchanges only energy across its boundary.  An isolated system is a hypothetical concept in which neither energy nor matter is exchanged across the boundary. Ecosystems are open systems; closed systems only exist experimentally, although the global geochemical cycles approximate to closed systems. A model is a simplified version of reality and can be used to understand how a system works and to predict how it will respond to change. A model inevitably involves some approximation and therefore loss of accuracy. The laws of thermodynamics govern the flow of energy in a system and the ability to do work. Systems can exist in alternative stable states or as equilibria between which there are tipping points. Destabilizing positive feedback mechanisms will drive systems towards these tipping points, whereas stabilizing negative feedback mechanisms will resist such changes. The second law of thermodynamics explains the inefficiency and decrease in available energy along a food chain and energy generation systems. As an open system, an ecosystem will normally exist in a stable equilibrium, either in a steady- state equilibrium or in one developing over time (for example, succession), and maintained by stabilizing negative feedback loops. Negative feedback loops (stabilizing) occur when the output of a process inhibits or reverses the operation of the same process in such a way as to reduce change—it counteracts deviation. Positive feedback loops (destabilizing) will tend to amplify changes and drive the system towards a tipping point where a new equilibrium is adopted. The resilience of a system, ecological or social, refers to its tendency to avoid such tipping points and maintain stability. Diversity and the size of storages within systems can contribute to their resilience and affect their speed of response to change (time lags). Humans can affect the resilience of systems through reducing these storages and diversity. The delays involved in feedback loops make it difficult to predict tipping points and add to the complexity of modelling systems.