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Sea level rise has been estimated to be on average between +2.6 mm and +2.9 mm per year ± 0.4 mm since 1993. Additionally, sea level rise has accelerated in recent years. For the period between 1870 and 2004, global average sea levels are estimated to have risen a total of 195 mm, and 1.7 mm ± 0.3 mm per year, with a significant acceleration of sea-level rise of 0.013 ± 0.006 mm per year per year. If this acceleration were to remain constant, the 1990 to 2100 sea level rise would range from 280 to 340 mm.〔 pdf is here ()〕 Another study calculated the period from 1950 to 2009, and measurements show an average annual rise in sea level of 1.7 ± 0.3 mm per year, with satellite data showing a rise of 3.3 ± 0.4 mm per year from 1993 to 2009.〔 〕 Sea level rise is one of several lines of evidence that support the view that the global climate has recently warmed.〔 Solomon ''et al.'', (Technical Summary, Section 3.4 Consistency Among Observations ), in ; Hegerl ''et al.'', (Executive summary, Section 1.3: Consistency of changes in physical and biological systems with warming ), in .〕 In 2007, the Intergovernmental Panel on Climate Change (IPCC) stated that it is very likely human-induced (anthropogenic) warming contributed to the sea level rise observed in the latter half of the 20th century.〔Hegerl ''et al.'', (Chapter 9: Understanding and Attributing Climate Change ), in .〕 The 2013 IPCC report (AR5) concluded, "''there is high confidence that the rate of sea level rise has increased during the last two centuries, and it is likely that GMSL (Global Mean Sea Level) has accelerated since the early 1900’s''. Sea level rises can considerably influence human populations in coastal and island regions and natural environments like marine ecosystems.〔 〕〔 〕 Sea level rise is expected to continue for centuries.〔 Because of the slow inertia, long response time for parts of the climate system, it has been estimated that we are already committed to a sea-level rise of approximately 2.3 meters for each degree Celsius of temperature rise within the next 2,000 years. It has been suggested that besides CO2 emissions reductions, a short term action to reduce sea level rise is to cut emissions of heat trapping gases such as methane and particulates such as soot.〔(''Cuts in some greenhouse gases could slow sea level rise'' ); "Methane, ozone and other short-lived pollutants have a big impact on ocean heights" April 12, 2013 Vol.183 #9 Science News〕 ==Mechanism== There are two main mechanisms that contribute to observed sea level rise:〔 IPCC, (FAQ 5.1: Is Sea Level Rising? ), in . 〕 (1) thermal expansion: ocean water expands as it warms - because of the increase in ocean heat content;〔 Albritton ''et al.'', (Technical Summary, Box 2: What causes sea level to change? ), in . 〕 and (2) the melting of major stores of land ice like ice sheets and glaciers. On the timescale of centuries to millennia, the melting of ice sheets could result in even higher sea level rise. Partial deglaciation of the Greenland ice sheet, and possibly the West Antarctic ice sheet, could contribute or more to sea level rise.〔IPCC, (Summary for Policymakers ), (Section C. Current knowledge about future impacts – Magnitudes of impact ) in .〕 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「Sea level rise」の詳細全文を読む スポンサード リンク
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