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Climate change has been a major issue in Australia since the beginning of the 21st century.〔(''Scientists Trace Extreme Heat in Australia to Climate Change'' ) 29 September 2014 NYT〕 In 2013, the CSIRO released a report stating that Australia is becoming hotter, and that it will experience more extreme heat and longer fire seasons because of climate change. In 2014, the Bureau of Meteorology released a report on the state of Australia's climate that highlighted several key points, including the dramatic increase in Australia's temperatures (particularly night-time temperatures) and the increasing frequency of bush fires, droughts and floods, which have all been linked to climate change.〔(【引用サイトリンク】url=http://www.bom.gov.au/state-of-the-climate/ )〕 Since the beginning of the 20th century Australia has experienced an increase of nearly 1 °C in average annual temperatures, with warming occurring at twice the rate over the past 50 years than in the previous 50 years. Recent climate events such as extremely high temperatures and widespread drought have focused government and public attention on the impacts of climate change in Australia. Despite a slight increase in overall rainfall in Australia, rainfall patterns are expected to be problematic, as rain has become heavier and infrequent, with little or no uptrend in rainfall in the Western Plateau and the Central Lowlands of Australia. Water sources in the southeastern areas of Australia have depleted due to increasing population in urban areas (rising demand) coupled with climate change factors such as persistent prolonged drought (diminishing supply). At the same time, Australia continues to have the highest per capita greenhouse gas emissions. Temperatures in Australia have also risen dramatically since 1910 and nights have become warmer.〔(【引用サイトリンク】title=Recent Changes )〕 A carbon tax was introduced in 2011 by the Gillard government in an effort to reduce the impact of climate change and despite some criticism, it has successfully reduced Australia's carbon dioxide emissions, with coal generation down 11% since 2008-09.〔(【引用サイトリンク】title=Big fall in electricity sector emissions since carbon tax )〕 The Australian Government under Prime Minister Tony Abbott has been criticised for being "in complete denial about climate change". Furthermore, the Abbott government repealed the statistically effectual carbon tax on 17 July 2014 in a heavily criticised move. The federal government and all state governments (New South Wales, Victoria, Queensland, South Australia, Western Australia,〔http://www.dec.wa.gov.au/our-environment/climate-change/index.html Climate Change (WA) Retrieved 27-01-2009〕 Tasmania,〔http://www.climatechange.tas.gov.au/ (Tas) Retrieved 27-01-2009〕 Northern Territory〔http://www.nt.gov.au/dcm/legislation/climatechange/ Climate Change (NT) Retrieved 27-01-2009〕 and the Australian Capital Territory) have explicitly recognised that climate change is being caused by greenhouse gas emissions, in conformity with the scientific opinion on climate change. Sectors of the population are actively campaigning against new coal mines and coal-fired power stations because of their concern about the effects of global warming on Australia.〔Steve Skitmore. (The New Climate Wedge: Farmers vs Coal Mining ). Friends of the Earth Australia.〕〔Andrew Fowler (13 April 2010). (Coal town's doctors raise child health alarm ). ABC News. Australian Broadcasting Corporation.〕〔(Campaigns ). Rising Tide Australia.〕 There is expected to be a net benefit to Australia of stabilising greenhouse gases in the atmosphere at 450ppm CO2 eq. The per-capita carbon footprint in Australia was rated 12th in the world by ''PNAS'' in 2011, considerably large given the small population of the country.〔(Which nations are really responsible for climate change - interactive map ) ''The Guardian'' 8 December 2011 (All goods and services consumed, source: Peters et al PNAS, 2011)〕 ==Pre-instrumental climate change== Paleoclimatic records indicate that during glacial maxima Australia was extremely arid,〔(Australasia )〕 with plant pollen fossils showing deserts extending as far as northern Tasmania and a vast area of less than 2 percent vegetation cover over all of South Australia and adjacent regions of other states. Forest cover was largely limited to sheltered areas of the east coast and the extreme southwest of Western Australia. During these glacial maxima the climate was also much colder and windier than today.〔Flannery, Tim, ''The Future Eaters: An Ecological History of the Australian Lands and People''; p. 115 ISBN 0-8021-3943-4〕 Minimum temperatures in winter in the centre of the continent were as much as 9 °C (16 °F) lower than they are today. Hydrological evidence for dryness during glacial maxima can also be seen at major lakes in Victoria's Western District, which dried up between around 20,000 and 15,000 years ago and re-filled from around 12,000 years ago.〔Water Research Foundation of Australia; ''1975 symposium: the 1973-4 floods in rural and urban communities''; seminar held in August 1976 by the Victorian Branch of the Water Research Foundation of Australia.〕 As one moves into the Holocene, evidence for climate change declines. During the early Holocene, there is evidence from Lake Frome in South Australia and Lake Woods near Tennant Creek that the climate between 8,000 and 9,500 years ago and again from 7,000 to 4,200 years ago was considerably wetter than over the period of instrumental recording since about 1885.〔Allen, R. J.; ''The Australasian Summer Monsoon, Teleconnections, and Flooding in the Lake Eyre Basin''; pp. 41-42. ISBN 0-909112-09-6〕 The research that gave these records also suggested that the rainfall flooding Frome was certainly summer-dominant rainfall because of pollen counts from grass species. Other sources〔Bourke, Patricia; Brockwell, Sally; Faulkner, Patrick and Meehan, Betty; "Climate variability in the mid to late Holocene Arnhem Land region, North Australia: archaeological archives of environmental and cultural change" in ''Archaeology in Oceania''; 42:3 (October 2007); pp. 91-101.〕 suggest that the Southern Oscillation may have been weaker during the early Holocene and rainfall over northern Australia less variable as well as higher. The onset of modern conditions with periodic wet season failure is dated at around 4,000 years before the present. In southern Victoria, there is evidence for generally wet conditions except for a much drier spell between about 3,000 and 2,100 years before the present,〔Water Research Foundation of Australia; ''1975 symposium''〕 when it is believed Lake Corangamite fell to levels well below those observed between European settlement and the 1990s. After this dry period, Western District lakes returned to their previous levels fairly quickly and by 1800 they were at their highest levels in the forty thousand years of record available. Elsewhere, data for most of the Holocene are deficient, largely because methods used elsewhere to determine past climates (like tree-ring data) cannot be used in Australia owing to the character of its soils and climate. Recently, however, coral cores have been used to examine rainfall over those areas of Queensland draining to the Great Barrier Reef.〔Lough, J. M. (2007), "Tropical river flow and rainfall reconstructions from coral luminescence: Great Barrier Reef, Australia", ''Paleoceanography'', 22, PA2218, .〕 The results do not provide conclusive evidence of man-made climate change, but do suggest the following: # There has been a marked increase in the frequency of very ''wet'' years in Queensland since the end of the Little Ice Age, a theory supported by there being no evidence for any large Lake Eyre filling during the LIA. # The dry era of the 1920s and 1930s may well have been the driest period in Australia over the past four centuries. A similar study, not yet published, is planned for coral reefs in Western Australia. There exist records of floods in a number of rivers, such as the Hawkesbury, from the time of first settlement. These suggest that, for the period beginning with the first European settlement, the first thirty-five years or so were wet and were followed by a much drier period up to the mid-1860s,〔Warner, R. F.; "The impacts of flood- and drought-dominated regimes on channel morphology at Penrith, New South Wales, Australia". IAHS Publ. No. 168; pp. 327-338, 1987.〕 when usable instrumental records start. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Climate change in Australia」の詳細全文を読む スポンサード リンク
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