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简介
鉴于世界本身的变化和发展，这似乎不大可能也许永远也不可能去构建一系列稳定而又永久性可持续发展的社会和经济安排。物种的发展,繁荣到灭亡，大气成分的变化，动态关联的关系网构成了如今的全球生态系统，当然这也随着时间的推移逐渐改变，从而改变人类物种的生态参数运行。地球上生物的进化和生态系统,都是一个队伍和启发式的过程。
文献综述
地球现在的年龄大概是四百五十万岁左右，大约介于宇宙年龄的四分之一到一半，到目前为止，地球是唯一一个已知生命宇宙行星，近四十亿年前开始，就有生物生活在这个星球上，所以地球上的生命的故事远比地球本身要渺小的很多。(Silvertown,1990)
人类物种是相对近期的原产地，人类已经在这个有生物活性的地球生活了约0.005%的时间，这个比例大约相当于一天55年的寿命。最初与其他类人猿发生分歧是在大约700万年前，南方古猿的前身在公元前700到200万年前，大约在170万年前，他们通过直立行走进化成人类。然而我们的直系祖先----智人,直立行走进化成人大概是在200000年前。
What is sustainability?
Introduction
It seems unlikely that it will ever be possible to construct a fixed set of social and economic arrangements that would be permanently sustainable in environmental and other terms, given that the world itself changes and evolves. Species develop, flourish and perish, the composition of the atmosphere changes, and the dynamically-interrelated network of relationships that constitutes the global ecology gradually transforms over time, thereby changing the ecological parameters within which the human species has to operate. The evolution of biological and ecological systems on this planet was and is a contingent and heuristic process.
Literature Review
The Earth is about four and a half billion years old, somewhere between one quarter and one half of the age of the universe. It is the only planet in the universe currently known to support life. Life began on this planet nearly four billion years ago, so the story of life on Earth is only a little shorter than that of the planet itself. (Silvertown, 1990)
The human species is of relatively recent origin. Humans have existed for some 0.005 per cent of the time during which there has been biological activity on the planet, a ratio approximately equivalent to one day in a 55 year lifespan. The initial divergence from other apes occurred some 7 million years ago. The precursor Australopithecus lived from 7 to 2 million years ago. Homo Erectus evolved, via Homo Habilis, some 1.7 million years ago. Our immediate ancestors, Homo Sapiens, evolved from Homo Erectus possibly as little as 200,000 years ago. From about 100,000 years ago Homo Sapiens occupied parts of Africa, and the warmer parts of Europe and Asia.
It is not clear at what stage we became a cultural species. It has been suggested that there is evidence for cultural behaviour from as far back as 60,000 or even 100,000 years ago. However, the earliest unambiguous evidence for sophisticated cultural behaviour, including a technology of tools and weapons, burial of the dead, fertility worship, paintings, sculptures and so on dates from some 40,000 years ago, as modern man, Homo Sapiens Sapiens, spread across Europe and replaced Neanderthal Man (now generally considered to be a member of the species Homo Sapiens). Humans reached Australia some 35,000 years ago, North America perhaps 20,000 years ago, and had spread across most of the ice-free world by the end of the last ice age, some 15,000 to 12,000 years ago. The first domestication of plants and animals happened some 12,000 years ago, and there were farming communities in various parts of the world by some 8,000 years ago (Moore, 1992). Some of these villages grew into the first small cities some 6,000 years ago. In comparison to the duration of life on Earth, therefore, contemporary human civilisation is of very recent origin.
Human beings are destroying the biological diversity of the planet with the carelessly grand waves of a monarch or a maniac. The current extinction crisis is shaping up as the worst in 65 million years. Unless ecological sustainability is valued along with economic development, the consequences will be catastrophic.
More than 99 per cent of all species that ever lived are extinct. Species have very varied lifespans, and while the blue-green algae have been here for about 3 billion years, the typical lifespan is very much shorter. The potential lifespan of the human species is unknown, but not infinite. However, premature extinction would be regrettable.
The changes in the global ecology indicate that we need to become more aware of the consequences of our actions, and to start to manage our affairs more consciously than has generally been the case in the past. This may mean that it will be necessary to evolve new political and economic structures and decision-making mechanisms in order to respond to these emerging global environmental demands. However, as indicated earlier, we may have to do so from a position of relative political and economic instability. This is likely to be a challenging process.
Many existing organisational, political, and economic concepts and structures are probably now inappropriate and unhelpful. It is unlikely that the necessary structures for international coordination, for example, will be evolved without some degree of organisational and political transformation. This in turn is unlikely to happen without a parallel evolution of the cultural and psychological concepts on which political and economic structures are ultimately based.
This is why any analysis, to be adequate, must include the relevant environmental, political, economic and socio-cultural factors. The sustainability of the human species can only be defined, ultimately, at the level of the interaction between the entire complex of human systems and all directly implicated environmental systems. To understand sustainability therefore requires some understanding of the behaviour of systems in general and of human and environmental systems in particular.
There are a number of definitions of sustainability currently in use. There is some consensus that a transition to a sustainable way of life means taking steps to try to reduce the risk that environmental and related problems will seriously affect or jeopardise the human species at some future time, and thereby to ensure that future generations have a reasonable prospect of a worthwhile existence. The question of sustainability is, therefore, one of enlightened self-interest. It requires finding ways in which the human species can live on this planet indefinitely, without compromising its future.
All species interact, change, and co-evolve with their environment. The human species is no exclusion. We are exclusive, however, in our ability to modify consciously some elements of the pattern of our interaction with the environment. It is no longer possible, given the current extent of human activity, to avoid making these management decisions as to how we wish to interact with the planet. For example, a decision not to cull the Scottish red deer, given that important natural predators no longer exist, is now a management decision, just as much as a decision to cull the deer. Every permutation of all decisions of this type has ecological consequences. Similarly, a decision to disregard information on current global ecological trends is a management decision, as much as is the decision to attempt to achieve some particular human-ecological balance.
While many would now agree that there is a need to find ways of living that are sustainable, the discussion to date has yet to generate a fundamental explanation that spans the issues and provides a coherent reason and direction for social change. The authors believe that the best prospect for an effective response to the global crisis lies in developing an analysis that can offer both; one that can both justify and inform a long-term, integrated and coherent strategy for change.
Such an approach is slightly unfamiliar in the UK. This is because Britain has a general philosophical ethos that is more empirical and instrumentalist than the mainland European intellectual tradition. Pragmatism and practicality are valued, abstract analysis is distrusted. This ethos underlies a situation in which specific and concrete responses to problems are valued (as indicating pragmatism and practicality) while more abstract appraisals (which might lead to more fundamental and comprehensive solutions) are often seen as being less useful. (Spash and Clayton, 1995)
The interaction between humans and their environment can be thought of as moving the planetary system along various axes simultaneously. If this happens at a rate that exceeds the rate at which other systems can adapt, that is, at a rate that exceeds the delay factor with which the phase space region that defines sustainability can move to follow the point at which the planet is positioned in phase space, then these other systems will become extinct. The species extinction rate therefore provides a partial measure of the rate of movement through phase space.
Global warming is likely to provide a number of examples of this effect. Vegetation distribution typically shifts some 200 km towards the poles with each 1°C rise in temperature. The forest migration rates at the end of the last glacial period were some 20 to 100 km per century. However, the projected rate of global warming will be perhaps 100 times faster than the rate of warming at that time. Many tree species will be unable to migrate at the necessary speed, which will in turn affect a large number of dependent species.#p#分页标题#e#
Multi-dimensionality is present in the concept of ‘primary environmental care' (PEC), which is evidently related to sustainable expansion and has become far and wide existing among development organisations in their efforts to put sustainable development into performance. PEC is classified as ‘the diversified for development advancements in the interactive region between economic, environmental and social systems' (Holmberg and Sandbrook 1992:31). Its ‘essential constituents' are:
§ Linking and fulfilling of essential needs—the economic goal;
§ Safety and best use of the environment—the environmental goal;
§ And authorizing of groups and communities—the social goal.
Environmental sustainability needs the preservation of imperative functions. Each of these principles has related with it a sustainability model (e.g. stable climate, sustainable harvest, critical load of pollution for an ecosystem, standards of air or water quality to defend human health) and a number of probable markers of environmental pressure (e.g. discharges) or environmental state (e.g. concentration of pollutant) to show whether the standard is at present being acted in accordance with with. Economic sustainability depends on the maintenance of the capital stock. (Daly, 1990, 1-6)
Conclusion
It seems unlikely that it will ever be possible to construct a fixed set of social and economic arrangements that would be permanently sustainable in environmental and other terms, given that the world itself changes and evolves. Species develop, flourish and perish, the composition of the atmosphere changes, and the dynamically-interrelated network of relationships that constitutes the global ecology gradually transforms over time, thereby changing the ecological parameters within which the human species has to operate. The evolution of biological and ecological systems on this planet was and is a contingent and heuristic process. It is unlikely that the appearance of the human species, for example, was an inevitable outcome of the process of evolution, just as the continued survival of the human species is in no sense guaranteed. There have been a number of points in the history of this planet at which events could probably have taken a different turn, and there will probably be many more such points in future.
It is impossible to eliminate all risk in such a contingent process. It is probably more accurate, therefore, to think in terms of reducing rather than eliminating the overall risk to which the human species might be exposed, and of reducing the number and impact of activities agreed to be unsustainable rather than aiming for a definable state called sustainability. In order to do this, it will probably be necessary to control particular activities, by restricting actions, for example, that place undue pressure on particularly sensitive or critical ecological functions.
The key to achieving sustainable development, therefore, is to understand and shape the interaction between complex adaptive natural systems and soft socio-economic systems in order to ensure that we always remain within our survival region at the intersection of the survival regions of all the systems on which we are dependent (Bergstrom, 1990, 215-228). Of course, the nature of this interaction between natural and socio-economic systems is itself constantly evolving, as species regenerate or become extinct, resources are exhausted or new reserves discovered, social and economic systems expand and collapse and new technologies are developed, disseminated and superseded. Thus both problems and solutions are dynamic.
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