U316 The Environmental Web
Block 1: Environmental Changes: Global Challenges
Summaries
Environmental problems are an important aspect of globalization - a concept that refers to the process and the experience of the increasing interconnectedness of the world.
Sustainability has emerged as a central issue of contemporary environmentalism in response to the charge that continued economic growth is undermining the long-term life-support systems of the planet.
The claim that less-developed nations have a right to benefit from economic growth in the same way that developed nations have in the past presents a serious challenge for advocates of sustainability.
'Sustainable development' makes an explicit connection between environmental issues and issues of global economic inequality. The concept suggests that it is possible to reconcile further social and economic development with envrionmental protection.
Mounting evidence about human-induced environmental change at a global scale is a cogent reminder that there is a continuing tension between calls for continued economic growth and environmental sustainability.
The predicament of people on small islands and other low-lying areas demonstrates that vulnerability to global environmental changes is not evenly distributed. This inequality raises important ethical and political issues about the reponsibility of people elsewhere in the world for these threats.
In the modern world claims about environmental risk and degradation must be backed up by scientific evidence.
Most of the major claims about human-induced global environmental change are contested to some degree, although there is an emerging consensus over some of the major points.
One of the main sources of contention is how the distinction should be made between human-induced changes and changes caused by natural variation - such as fluctuations of climate or sea-level and geological instability.
An added difficulty with tracking the impact of human activities arising because of the patterns of stability of many of the physical and biological systems in question. Because systems may reach a threshold and change their state quite suddenly, it can be difficult to gauge the human contribution to change or to predict when a change of state might occur.
There are many uncertainties in the state of knowledge about environmental change, both because of inadequacies of the available data and analysis, and because of the inherent unpredicatbility of some of the systems that are being studied. This means that there will always be a play-off between confidence and uncertainty.
A sense of the dynamism and turbulence that is part of the natural world itself increasingly forms the backdrop to the sustainability issue - raising questions about what it is we are trying to sustain and how the goals of development should be set.
Chapter 2
The discovery of uninhabited oceanic islands played an important strategic role in the era of European maritime expansion arund the globe.
The natural endowments and felicitous location of oceanic islands prompted comparisons with the biblical Garden of Eden in the imagination of Europeans.
The disastrous impact of provisioning stops and settlement on small oceanic islands gave European colonists an early experience of environmental degradation. It was a forerunner of what has come to be called 'unsustainable development'.
Oceanic islands provided important early lessons about the vulnerability of island wildlife to human impacts, including invasion by introduced animals.
Settlers and administrators on small island colonies learnt some important lessons about the governance of their societies - and especially about managing their relations with the environment - from their experience of environmental degradation.
The main legacy of the early European experience of uninhabited oceanic islands has been the idea that the ideal landscape is the 'pristine' one, devoid of any noticeable human alteration.
The privileging of unspoit wilderness as the ideal model of nature in the western imagination has had a major impact both on the imagery of both the tourist industry and modern environmentalism.
Studies of island species gave pioneering evolutionary theorists such as darwin and Wallace important insights into the processes of diversification of living organisms.
The same processes that contribute to the peculiar creativity of island environments with regard to biological diversification also render island species especially vulnerable to environmental changes. This has been mainfest in high rates of extinction of island fauna.
Polynesian colonisation of oceanic islands seems to have had deleterious effects on island ecosystems in much the same way as European settlement led to severe environmental disturbance on islands.
Lack of coeveolution between human social systems and ecosystesm - particularly following human migration - is a significan contributing factor to unsustainable practices.
Chapter 3
Human impacts can compound the stress caused by natural variability to induce catastrophic shifts in an ecosystem. These shifts often result in a much lower level of biodiversity.
Ecosystems belong to the category of complex systems, which means they have the potential to stabilize or to transform themselves in response to changing conditions. The tangled feedback loops that enable ecosystems and other complex systems to adjust also make it extremely difficult to predict future states of the system.
Preserving redundancy tends to be the best means of maintaining resilience in an ecosystem or other complex system.
Human hunting and gathering communities generally keep their demands on the biological productivity of ecosystems at a low level, which conserves ecosystem resilience.
The tranisition to agricultural production involves the channelling of a high proportion of biological production to human consumers and entails a significant simplification of ecosystems. This simplification tends to reduce natural resilience.
Agricultural societies must find ways to cope with the effects of seasonal and longer-term climatic variability if they are to endure. This means that famine prevention and relief is usually an important aspect of the governance of these societies.
Integration of traidtional agricultural societies into global markets exposes peasant producers to the uncertainties of the global economic system, which can compound the uncertainties of climatic variability.
Top-down governance has limitations when it comes to reponding to environmental and economic variability.
Because of economic inequality and environmental variability across the planet, there is unevenness to global markets. Global market pressures encourage maximal development of resources, which can undermine resilience in economic and ecological systems.
Our growin understanding of global interconnections raises ethical questions about our obligations to 'others' distant in time and space, and underscores the need for governance at a global scale. Effective governance requires input and feedback from throughout the social system.
Chapter 4
Human contact with the Antarctic is very recent. Once humans had discovered Antarctica there was a rush of expeditions southwards from the 19th-century colonial powers.
Apart from the Antarctic Peninsula, Antarctica is roughly circular, centred approcimately on the South Pole with an area about the same size as Europe. A polar projection map of the Antarctic is centred on the South Pole, with lines of longitude radiating from the pole and lines of latitude shown as concentric circles around the pole.
A Mercator projection map shows longitude as vertical lines and latitude as horizontal lines.
Several countries have made territorial claims in Antarctica but these are not recognized in International Law. Countries with territorial claims, plus several others, operate research stations in Antarctica, and these are mostly located on the coast.
The area of Antarctica is variable, depending on the area of ice-shelf attached to it, and different figures for the total area are given by different sources. About 98% of the continent is covered in ice.
When using the Internet to answer a question it is possible to avoid distraction and minimize time online by posing a carefully considered and focused question, deciding in advance what information is needed to answer the question, then going offline to evaluate the information and draw conclusions.
Air temperatures in Antarctica are dependent on the amount of incident solar radiation received and the amount of heat gained from the oceans. Antractica is often thought of as having an extreme, unremittingly cold climate, but in fact it has a seasonal climate, with relatively mild summers on the coast. Inland areas have a shorter summer and a coreless winter.
Antarctica lay much closer to the Equator 195 million years ago, but continental drift has moved it to its present polar position. The thick sheet of glacial ice covering most of the continent probably developed within the last 20 million years. Glacial ice flows off the continent via glaciers and either remains attached to form a floating ice-shelf or breaks off at the edges to form icebergs.
Chapter 5
The Antarctic Circumpolar Current regulates and extends the Antarctic environment as far north as the polar front. The waters south of the polar front circulate clockwise around Antarctica.
The sea surface freezes at -1.8 deg C, and sea-ice covers an area greater than the size of Antarctica in winter but less than a quarter of this area at the height of summer. The frazil-pancake cycle is the most rapid means of forming pack ice and seawater is trapped between the ice crystals.
Food webs consist of primary producers, herbivores, carnivores and top carnivores and these are structured into trophic levels.
The transfer of energy between trophic levels is very inefficient.
Plants and animals are not distributed uniformly across the Southern Ocean (or any other ocean), and physical factors such as ocean circulation play a major role in ecosystem variability.
Krill are the key Antarctic species and large predators can be supported as a result of their swarming behaviour.
The sea-ice around Antarctica is a component of the krill habitat.
Antarctic productivity may be limited by a lack of iron.
Chapter 6
Unsustainable exploitation of seal and whale populations in Antarctica in the early 20th century led to a steep decline in the numbers of these animals.
The Discovery Investigations research programme, set up to examine the impact of unsustainable exploitation, was instrumental in advancing our understanding of the Antarctic marine environment, ecosystem and ocean circulation.
The International Whaling Commission (IWC) was set up as an international attempt to manage the whaling industry. Despite whales numbers severely declining after World War II, it took until 1984 before a moratorium on whaling was implemented. In 2002 this moratorium was still in place.
Several countries made territorial claims in Antarctica before World War II, but the first permanent base in Antarctica awas not establisehd until 1944, by the British.
No nation could work out how to enforce sovereignty in Antarctica. With the American Operation Highjump, and the expansion of the FIDS, tension increased.
The International Geophysical Year of 1957-58 was the vehicle through which internationalization occurred. The result of this scientific event was the Antarctic Treaty System (ATS).
The Antarctic Treaty has 12 original signatories, although today the numbers have increased. Decisions on Antarctic matters south of 60 deg S are reached through the ATS by consensus.
The ATS has introduced four futher pieces of legislation determining governance of Antarctica. The fourth - the Protocol on Environmental Protection to the Antarctic Treaty (1998) - was introduced because of the failure of a convention on mining (CRAMRA). This protocol now acts as a gatekeeper to Antarctica and means that an EIA must be prepared for all activities.
Antarctica is now a region of science and tourism. The resource exploitation is fishing activity, which is controlled by CCAMLR.
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