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| by Mike Pope, ScienceAlert.com, September 8, 2009 From Spizbergen in the Arctic to Charcot Island off the Antarctic coast, more than 150,000 glaciers are melting. They are doing so much quicker than predicted by the Intergovernmental Committee on Climate Change in 2007. Even the Greenland and West Antarctica ice sheets, until recently thought invulnerable to global warming, have begun melting and showing signs of collapse. The melting of the west Antarctic ice shelf and the Greenland ice cap alone would increase sea levels. The effect on sea level by the melting of mountain glaciers and other land-based ice and snow in the Andes, Rocky Mountains, European ranges, the Hindu Kush and Himalayas has not been fully calculated but, combined, this melting of land based snow and ice has the potential to raise sea levels by at least 2-3m by mid century. Common sense tells us that melting of land-based ice produces water which ultimately flows to the sea. With accelerated melting of glacier ice, which is now occurring, a rise in sea levels is inevitable. It is the speed at which ice is melting that should give greatest concern because this makes the consequences all the more inescapable and uncontrollable. It increases the prospect of sea levels rising dangerously over the next 40-50 years particularly if, as predicted, atmospheric temperatures continue rising. Politicians, such as Prime Minister Kevin Rudd, Opposition Leader Malcolm Turnbull and Queensland Premier Anna Bligh, tell us that we must learn to live with the effects of global warming. The problem is that those effects are likely to bring about hardships such as hunger and disease entailing massive loss of life as the supply of fresh water diminishes and coastal flooding by salt water increases. Nevertheless, our political leaders believe it is far more important to use the pretext of preserving jobs in the short term rather than reduce CO2 emissions. Above all, they assert that we must support and protect the Australian coal industry. They seek on-going use of coal, both for generating domestic electricity supplies and as a major export - of pollution - on which governments and industry depend for revenue and cheap electricity. They claim this gives Australia a competitive edge in export trade. This claim is used by Government and Opposition as an excuse and justification for massively subsidising the production and use of the world’s largest CO2 pollutant, coal. Less contentiously they assert that Australia acting alone can make very little difference to global greenhouse gas emissions. They are right. However, significantly reducing greenhouses gas emissions can place Australia in the position of being a world leader in this area; a position which gives it the moral authority to demand that the worst polluters - the USA and BRIC (Brazil, Russia, India and China) countries - follow its lead. As things stand, Australia is the largest coal exporter in the world and one of its largest per-capita emitters of greenhouse gasses. It therefore behoves us to examine the consequences of this lack of political will, not only for Australia but for other parts of the world. Well before sea levels rise by as much as a metre, it is certain that during tidal surges and “king” high tides considerable coastal erosion will occur. Infrastructure and property built on low coastal areas will be lost or damaged, either as a result of undermined foundations or repetitive flooding. As sea levels continue to rise, thousands of dwellings, port facilities such as wharves, cargo storage sheds and other amenities, anywhere along low-lying areas of the Australian coast, may well sustain damage. A rise of a metre or more in sea level would cause flooding with property losses in every capital city in Australia except Canberra and in many of the major provincial cities located on the coast. A possible 2-3m rise in sea level would cause substantial flooding of the east coastal plain which is extensively used for agriculture, producing vast quantities of fruit, vegetables, spices, nuts and sugar. Production would be disrupted and reduced. Transport infrastructure would be damaged making supply to major cities difficult and limiting export trade. International airports at Sydney, Brisbane and Cairns would be flooded and become unusable. Roads, bridges and port facilities would be damaged and could not be protected since it should be assumed that with increasing surface temperatures, sea levels will continue to rise as more and more ice melts. Housing and other building losses located on low lying coastal areas would be high. Even icons such as the Sydney Opera House may not be spared since a rise in sea level could undermine its foundations. Damage to the Queensland and New South Wales economies would be significant. In other Australian states loss of coastal infrastructure including road and rail would be so extensive as to make it impossible to build effective protection. In the north-west, flooding around Dampier, Port Headland, Learmonth, and the Gascoyne would occur. Property losses would be high, port facilities could become inoperable and mineral exports might be limited or cease due to flooding of the rail easement. Such losses shrivel to insignificance when compared with the effects of a 2m rise in sea level on China and South-East Asia. Shanghai and its hinterland, with a population of more than 20 million would be totally and permanently flooded. Its businesses, thriving commerce and most of its assets would be lost and its people disbursed, if they survived. Similar losses would occur in Guangzhou (Canton) and Hong Kong affecting 10 million people. Eighty per cent of the worlds’ largest cities are located on or near the coast. All would sustain damage from a 1m rise in sea level. The delta regions of many of the worlds’ great rivers are fertile, intensely cultivated areas producing high yields of staple crops, such as rice, on which wider populations depend. The Mekong, Irrawaddy, Ganges, even the Nile, are all such areas. They would be completely drowned by salt water, destroying their capacity to produce food and displacing the often dense populations living there. In Europe, the great trading ports of Amsterdam and Rotterdam would be flooded, as would half of the Netherlands and large swathes of coastal Belgium and Germany. All of the north German ports would be flooded. Millions would lose property, their jobs and national economies would crumble. The fenlands separating East Anglia from the rest of England would be flooded from the Wash southwards towards Cambridge. Low lying lands of the Thames, Mersey and other estuaries would be drowned by the sea. The southern coastline of the USA from Florida to Texas would be devastated by flooding, much of it permanent. Cities such as New Orleans and possibly Miami would be severely damaged or lost, their people dispersed, their economies destroyed. Major cities such as New York and Los Angeles would also sustain damage to infrastructure including port facilities. Coastal destruction of this kind will occur world-wide. It will occur over decades but become increasingly evident and damaging year by year. An exacerbating problem is that rising sea levels will occur at the same time as water shortages induced by the loss of glaciers and river flows. The net effect will be an inability to produce food or provide water needed to sustain dense populations. Increasingly severe damage caused by these events will make it impossible to relocate or re-house displaced people. In more densely populated countries such as China, Bangladesh and India, massive loss of life seems likely to occur. Some countries will be drowned out of existence. Others will cease to exist as nation states. At worst, millions or even billions of people will die, vast areas of the most productive agricultural land will be submerged and essential infrastructure will be damaged or lost. They will die from starvation, diseases or drowning. Entire countries and their economies could collapse; some will struggle to maintain subsistence living conditions, yet others will adopt hostile protectionist alliances. The global economy as we know it today may well cease to exist. These outcomes are avoidable but only if nations, particularly the worst emitters of greenhouse gasses, reform their practices so as to effectively reduce global emissions by 30-40 per cent of 2000 levels by 2020. There is little indication of moves to make this happen on a voluntary basis. This adds to the need for the UN sponsored 2009 Copenhagen Conference to exert pressure on all major emitters. Those countries which decline to take effective verifiable action to reduce their emissions should be compelled to do so and they can be. The best way of achieving this is to penalise non-complying countries by applying import tariffs equivalent to CO2 emissions caused by production of their exports. If the United States, the European Union and low emitters enforced such action, others would reduce their emissions or loose their export markets with the same desirable reduction of greenhouse gas emissions. An opinion provided by OnlineOpinion.com.au - Australia's e-journal of social and political debate. |
Link: http://www.sciencealert.com.au/opinions/20090809-19715.html
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