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'{{about|the current and future rise in sea level associated with [[global warming]]|sea level changes in Earth's history|Sea level#Changes through geologic time{{!}}Sea level}} {{pp-move-indef}} {{Multiple image |direction=vertical | alignr=right | image1=Trends in global average absolute sea level, 1870-2008 (US EPA).png | image2= Post-Glacial Sea Level.png | width=250 | caption1=Trends in global average absolute sea level, 1870–2008.<ref> {{cite web | author=US Environmental Protection Agency (US EPA) | title= Sea Level: Climate Change: US EPA | url=http://www.epa.gov/climatechange/science/indicators/oceans/sea-level.html | publisher=US EPA | year=2010 }} </ref> | caption2=Changes in sea level since the end of the last glacial episode. }} '''Current sea level rise''' is about 3&nbsp;mm/year worldwide. According to the US [[National Oceanic and Atmospheric Administration]] (NOAA), "this is a significantly larger rate than the sea-level rise averaged over the last several thousand years", and the rate may be increasing.<ref>{{cite web|title=Is sea level rising?|url=http://oceanservice.noaa.gov/facts/sealevel.html|publisher=NOAA National Ocean Service|accessdate=2014-06-19}}</ref> Sea level rises can considerably [[Effects of climate change on humans|influence human]] populations in coastal and island regions<ref name=wg1-5-5-1> {{AR4|WG1|chapter=5|section=Section 5.5.1: Introductory Remarks|section-url=http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5.html#5-5-1 }}</ref> and natural environments like [[marine ecosystem]]s.<ref name=wg2-4-4-9> {{citation | author= Fischlin | author2=''et al.'' | chapter=Section 4.4.9: Oceans and shallow seas – Impacts | chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch4s4-4-9.html | title=Chapter 4: Ecosystems, their Properties, Goods and Services | url=http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch4.html | page=[http://www.ipcc.ch/pdf/assessment-report/ar4/wg2/ar4-wg2-chapter4.pdf#page=24 234] | editor={{Harvnb|IPCC AR4 WG2|2007}} }}</ref> Between ur nan and ur mom, global average sea levels rose a total of {{convert|69|mm|in|abbr=on}}, and {{convert|6.9|mm|in|abbr=on}} per lel xd.<ref name="Church L01602">{{cite journal | last = Church | first = John | author-link = John A. Church | last2 = White | first2 = Neil | title = A 20th century acceleration in global sea-level rise | journal = [[Geophysical Research Letters]] | volume = 33 | date = January 6, 2006 | url = http://www.agu.org/pubs/crossref/2006/2005GL024826.shtml | doi = 10.1029/2005GL024826 | id = L01602 | accessdate = 2010-05-17 | page = L01602 | bibcode=2006GeoRL..3301602C | ref = harv }} pdf is here [http://naturescapebroward.com/NaturalResources/ClimateChange/Documents/GRL_Church_White_2006_024826.pdf]</ref> From 1950 to 2009, measurements show an average annual rise in sea level of 1.7 ± 0.3&nbsp;mm per year, with satellite data showing a rise of 3.3 ± 0.4&nbsp;mm per year from 1993 to 2009,<ref> {{cite journal |first1= Robert J. |last1= Nicholls |first2= Anny |last2=Cazenave |authorlink2=Anny Cazenave |title= Sea-Level Sea-Level Rise and Its Impact on Coastal Zones |journal=[[Science (journal)|Science Magazine]] |date= 18 June 2010 |volume= 328 |issue= 5985 |pages= 1517–1520 |doi=10.1126/science.1185782 |url=http://www.sciencemag.org/content/328/5985/1517.full |bibcode = 2010Sci...328.1517N }}</ref> The reason for recent increase is unclear, perhaps owing to decadal variation.<ref> IPCC, [http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains1.html#1-1 Synthesis Report, Section 1.1: Observations of climate change], in {{Harvnb|IPCC AR4 SYR|2007}}. </ref> It is unclear whether the increased rate reflects an increase in the underlying long-term trend.<ref> IPCC, [http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains1.html#1-1 Synthesis Report, Section 1.1: Observations of climate change], in {{Harvnb|IPCC AR4 SYR|2007}}; {{cite web | year=2009 | author=Dahlman, L. | title=NOAA Climate Portal: ClimateWatch Magazine: Climate Change: Global Sea Level | url=http://www.climatewatch.noaa.gov/article/2009/climate-change-sea-level | publisher=NOAA Climate Services | accessdate=2011-07-29 }} </ref> There are two main mechanisms that contribute to observed sea level rise:<ref> IPCC, [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-5-1.html FAQ 5.1: Is Sea Level Rising?], in {{Harvnb|IPCC AR4 WG1|2007}}. </ref> (1) [[thermal expansion]]: ocean water expands as it warms;<ref> Albritton ''et al.'', [http://www.grida.no/climate/ipcc_tar/wg1/013.htm#b4 Technical Summary, Box 2: What causes sea level to change?], in {{Harvnb|IPCC TAR WG1|2001}}. </ref> and (2) the melting of major stores of land ice like [[ice sheet]]s and [[glacier]]s. Sea level rise is one of several lines of evidence that support [[Scientific consensus on climate change|the view that the global climate has recently warmed]].<ref> Solomon ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/tssts-3-4.html Technical Summary, Section 3.4 Consistency Among Observations], in {{Harvnb|IPCC AR4 WG1|2007}}; Hegerl ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains1-3.html Executive summary, Section 1.3: Consistency of changes in physical and biological systems with warming], in {{Harvnb|IPCC AR4 SYR|2007}}.</ref> In 2007, the [[Intergovernmental Panel on Climate Change]] (IPCC) stated that it is very likely [[Attribution of recent climate change|human-induced]] ([[anthropogenic]]) warming contributed to the sea level rise observed in the latter half of the 20th century.<ref>Hegerl ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-es.html Chapter 9: Understanding and Attributing Climate Change], in {{Harvnb|IPCC AR4 WG1|2007}}.</ref> Sea level rise is expected to continue for centuries.<ref name=nrccon/> In 2013, the [[Intergovernmental Panel on Climate Change]] (IPCC) projected that during the 21st century, sea level will rise another 26cm to 82cm in its fifth assessment report.<ref>{{cite web|last1=Church|first1=John|last2=Clark|first2=Peter|title=Chapter 13: Sea Level Change - Final Draft Underlying Scientific-Technical Assessment|url=http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter13.pdf|website=http://www.climatechange2013.org/|publisher=IPCC Working Group I|accessdate=January 21, 2015}}</ref> More recent projections assessed by the [[US National Research Council]] (2010)<ref name=nrcpro/> suggest possible sea level rise over the 21st century of between {{convert|56|and|200|cm|in|abbr=on}}. The Third [[National Climate Assessment]] (NCA), released May 6th, 2014, projects a sea level rise of 1 to 4 feet by 2100(30-120 cm).<ref>{{cite web|title=Third National Climate Assessment|url=http://nca2014.globalchange.gov/report/our-changing-climate/sea-level-rise|website=National Climate Assessment|accessdate=25 June 2014}}</ref> 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 {{convert|4|to|6|m|ft|abbr=on}} or more to sea level rise.<ref>IPCC, [http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spm.html Summary for Policymakers], [http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spmsspm-c-15-magnitudes-of.html Section C. Current knowledge about future impacts – Magnitudes of impact] in {{Harvnb|IPCC AR4 WG2|2007}}.</ref> Work by a team led by [[Veerabhadran Ramanathan]] of the [[Scripps Institution of Oceanography]] suggests that a quick way to stave off impending sea level rise is to cut emissions of short-lived climate warmers such as [[methane]] and [[soot]].<ref>[http://www.sciencenews.org/view/generic/id/349626/description/News_in_Brief_Cuts_in_some_greenhouse_gases_could_slow_sea_level_rise ''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]]</ref><ref>{{doi|10.1038/nclimate1869}}</ref> {{toclimit|3}} == Overview of sea-level change == === Local and eustatic sea level === [[File:Mass balance atmospheric circulation.png|thumb|[[Water cycle]]s between ocean, atmosphere, and [[glacier]]s.]] Local mean sea level (LMSL) is defined as the height of the sea with respect to a land benchmark, averaged over a period of time (such as a month or a year) long enough that fluctuations caused by [[ocean surface wave|waves]] and [[tide]]s are smoothed out. One must adjust perceived changes in LMSL to account for vertical movements of the land, which can be of the same order (mm/yr) as sea level changes. Some land movements occur because of [[isostasy|isostatic]] adjustment of the [[Mantle (geology)|mantle]] to the melting of [[ice sheet]]s at the end of the last [[ice age]]. The weight of the ice sheet depresses the underlying land, and when the ice melts away the [[post-glacial rebound|land slowly rebounds]]. [[Atmospheric pressure]], [[ocean current]]s and local ocean temperature changes also can affect LMSL. "[[Eustasy|Eustatic]]" change (as opposed to local change) results in an alteration to the global sea levels, such as changes in the volume of water in the world oceans or changes in the volume of an [[ocean basin]].<ref name="Oilfield Glossary">{{cite web |url=http://www.glossary.oilfield.slb.com/Display.cfm?Term=eustatic%20sea%20level|title=Eustatic sea level |author= |work=Oilfield Glossary |publisher= Schlumberger Limited|accessdate=10 June 2011}}</ref> === Short-term and periodic changes === Many factors can produce short-term (a few minutes to 18.6 years) changes in sea level. {| class="wikitable" ! Short-term (periodic) causes ! Time scale <br /> (P = period) ! Vertical effect |- ! colspan="3" style="background:lightgrey;"| Periodic sea level changes |- | Diurnal and semidiurnal [[Earth tide|astronomical tides]] || 12–24 h P || 0.2–10+ m |- | Long-period tides || &nbsp; || &nbsp; |- | Rotational variations ([[Chandler wobble]]) || 14 month P || |- | Lunar Node [[Earth tide|astronomical tides]] || 18.613 year || |- ! colspan="3" style="background:lightgrey;"| Meteorological and oceanographic fluctuations |- | Atmospheric pressure || Hours to months || −0.7 to 1.3 m |- | Winds ([[storm surge]]s) || 1–5 days || Up to 5 m |- | [[Evaporation]] and [[Precipitation (meteorology)|precipitation]] (may also follow long-term pattern) || Days to weeks || &nbsp; |- | Ocean surface [[topography]] (changes in water density and currents) || Days to weeks || Up to 1 m |- | [[El Niño]]/[[southern oscillation]] || 6 mo every 5–10 yr || Up to 0.6 m |- ! colspan="3" style="background:lightgrey;"| Seasonal variations |- | [[Season]]al water balance among oceans (Atlantic, Pacific, Indian) || &nbsp; || &nbsp; |- | Seasonal variations in slope of water surface || &nbsp; || &nbsp; |- | River runoff/floods || 2 months || 1 m |- | Seasonal water density changes (temperature and [[salinity]]) || 6 months || 0.2 m |- ! colspan="3" style="background:lightgrey;"| Seiches |- | [[Seiche]]s (standing waves) || Minutes to hours || Up to 5 m |- ! colspan="3" style="background:lightgrey;"| Earthquakes |- | [[Tsunami]]s (generate catastrophic long-period waves) || Hours || Up to 10 m |- | Abrupt change in land level || Minutes || Up to 10 m |} == Longer-term changes == Various factors affect the volume or mass of the ocean, leading to long-term changes in eustatic sea level. The two primary influences are temperature (because the density of water depends on temperature), and the mass of water locked up on land and sea as fresh water in rivers, lakes, glaciers, [[polar ice cap]]s, and [[sea ice]]. Over much longer [[geological timescale]]s, changes in the shape of oceanic basins and in land–sea distribution affect sea level. Observational and modelling studies of [[Retreat of glaciers since 1850|mass loss from glaciers and ice caps]] indicate a contribution to sea-level rise of 0.2–0.4&nbsp;mm/yr, averaged over the 20th century. === Glaciers and ice caps === Each year about 8&nbsp;mm of [[Precipitation#Measurement|precipitation (liquid equivalent)]] falls on the [[Antarctic ice sheet|ice sheets in Antarctica]] and [[Greenland ice sheet|Greenland]], mostly as snow, which accumulates and over time forms glacial ice. Much of this precipitation began as water vapor evaporated from the ocean surface. If no ice returned to the oceans, sea level would drop 8&nbsp;mm every year. To a first approximation, the same amount of water appeared to return to the ocean in [[iceberg]]s and from ice melting at the edges. Scientists previously had estimated which is greater, ice going in or coming out, called the [[Glacier mass balance|mass balance]], important because a nonzero balance causes changes in global sea level. High-precision [[gravimetry]] from [[Gravity Recovery and Climate Experiment|satellites]] in low-noise flight determined that Greenland was losing more than 200 billion tons of ice per year, in accord with loss estimates from ground measurement.<ref>[http://www.skepticalscience.com/greenland-cooling-gaining-ice-intermediate.htm Skeptical Science: Is Greenland gaining or losing ice?]</ref> The rate of ice loss was accelerating,<ref>[http://www.sciencenews.org/view/generic/id/346332/description/Sea_level_rise_overflowing_estimates ''Sea level rise overflowing estimates; Feedback mechanisms are speeding up ice melt''] November 8, 2012 [[Science News]]</ref> having grown from 137 gigatons in 2002–2003.<ref>{{cite doi|10.1029/2009GL040222}}</ref> The total global ice mass lost from Greenland, Antarctica and Earth's glaciers and ice caps during 2003–2010 was about 4.3 trillion tons (1,000 cubic miles), adding about 12&nbsp;mm (0.5 in) to global sea level, enough ice to cover an area comparable to the United States 50&nbsp;cm (1.5 ft) deep.<ref>{{cite web|title=NASA Mission Takes Stock of Earth's Melting Land Ice|url=http://www.nasa.gov/topics/earth/features/grace20120208.html|work=NASA/JPL-Caltech/University of Colorado|publisher=NASA|accessdate=25 April 2013|date=February 2012}}</ref> [[Ice shelf|Ice shelves]] float on the surface of the sea and, if they melt, to a first order, they do not change sea level. Likewise, shrinkage/expansion of the [[North pole|northern polar]] [[ice cap]] which is composed of floating [[pack ice]] does not significantly affect sea level. Because ice shelf water is fresh, however, melting would cause a very small increase in sea levels, so small that it is generally neglected. * The melting of small glaciers and [[Polar region|polar]] ice caps on the margins of Greenland and the [[Antarctic Peninsula]] melt, would increase sea level around 0.5 m. Melting of the [[Greenland ice sheet]] or the [[Antarctic ice sheet]] would produce 7.2 m and 61.1 m of sea-level rise, respectively.<ref>Anisimov ''et al.'', [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/412.htm Section 11.2.1.2: Models of thermal expansion], [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/412.htm#tab113 Table 1.3], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> The collapse of the grounded interior reservoir of the [[West Antarctic Ice Sheet]] would raise sea level by 5–6 m.<ref>[http://www.ldeo.columbia.edu/~mstuding/wais.html Geologic Contral on Fast Ice Flow – West Antarctic Ice Sheet<!-- Bot generated title -->]</ref> * The interior of the Greenland and Antarctic ice sheets, as of 2009, was sufficiently high (and therefore cold) that is would require [[millennia]] before those sheets would be lost by direct melt alone.{{Citation needed|date=November 2011}} Those ice sheets would be substantially reduced in mass through acceleration in flow and enhanced iceberg [[Ice calving|calving]] long before a direct melt could occur, although direct melt and calving occur in tandem. With feedback factors including the lost heat reflectance of the retreating ice, melt at the fringes of the ice caps and sub-ice-shelf melting in Antarctica could continue to significantly increase.{{Citation needed|date=December 2011}} * [[Climate change]]s during the 20th century were estimated from modelling studies to have led to contributions of between −0.2 and 0.0&nbsp;mm/yr from Antarctica (the results of increasing precipitation) and 0.0 to 0.1&nbsp;mm/yr from Greenland (from changes in both precipitation and [[surface runoff|runoff]]).{{Citation needed|date=December 2011}} * Estimates suggest that Greenland and Antarctica have contributed 0.0 to 0.5&nbsp;mm/yr over the 20th century as a result of long-term adjustment to the end of the last ice age{{Citation needed|date=December 2009}}. The current rise in sea level observed from tide gauges, of about 1.8&nbsp;mm/yr, is within the estimate range from the combination of factors above<ref name="grida2001">Anisimov ''et al.'', [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/408.htm Chapter 11: Changes in Sea Level], [http://www.grida.no/climate/ipcc_tar/wg1/428.htm Section 11.4: Can 20th century sea level changes be explained?], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> but active research continues in this field. In 1992, satellites began recording the change in sea level;<ref>{{cite web | url = http://sealevel.jpl.nasa.gov/missions/topex/ | title = Ocean Surface Topography from Space | publisher = NASA/JPL}}</ref><ref>{{cite web | url = http://sealevel.jpl.nasa.gov/ | title = Ocean Surface Topography from Space | publisher = NASA/JPL}}</ref> they display an acceleration in the rate of sea level change, but they have not been operating for long enough to work out whether this signals a permanent rate change, or an artifact of short-term variation.{{Citation needed|date=February 2011}} === Short-term variability and long-term trends === On the timescale of years and decades, sea level records contain a considerable amount of variability.<ref name="ipcc_a">Bindoff ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5.html Chapter 5: Observations: Oceanic Climate Change and Sea Level], [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5-2-4.html Section 5.5.2.4: Interannual and decadal variability and long-term changes in sea level], in {{Harvnb|IPCC AR4 WG1|2007}}.</ref> For example, approximately a 10&nbsp;mm rise and fall of global mean sea level accompanied the 1997–1998 [[El Niño-Southern Oscillation]] (ENSO) event, and a temporary 5&nbsp;mm fall accompanied the 2010–2011 event.<ref>{{cite web |url=http://www.sciencedaily.com/releases/2012/11/121119172938.htm |title=What Goes Down Must Come Back Up: Effects of 2010–11 La Niña On Global Sea Level |date=2012-11-19 |publisher=Science News |accessdate=2012-11-26}}</ref> Interannual or longer variability is a major reason why no long-term acceleration of sea level has been identified using 20th century data alone. However, a range of evidence clearly shows that the rate of sea level rise increased between the mid-19th and mid-20th centuries.<ref>Bindoff ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5.html Chapter 5: Observations: Oceanic Climate Change and Sea Level], [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-5-2-4.html Section 5.5.2.4: Interannual and Decadal Variability and Long-Term Changes in Sea Level], in {{Harvnb|IPCC AR4 WG1|2007}}.</ref> Sea level acceleration up to the present has been about 0.01&nbsp;mm/yr² and appears to have started at the end of the 18th century. Sea level rose by 6&nbsp;cm during the 19th century and 19&nbsp;cm in the 20th century.<ref>{{cite journal|last=Jevrejeva|first=Svetlana|author2=J. C. Moore |author3=A. Grinsted |author4=P. L. Woodworth |title=Recent global sea level acceleration started over 200 years ago?|journal=Geophysical Research Letters|date=April 2008|volume=35|issue=8|doi=10.1029/2008GL033611|accessdate=25 April 2013|bibcode = 2008GeoRL..35.8715J }}</ref> Evidence for this includes geological observations, the longest instrumental records and the observed rate of 20th century sea level rise. For example, geological observations indicate that during the last 2,000 years, sea level change was small, with an average rate of only 0.0–0.2&nbsp;mm per year. This compares to an average rate of 1.7 ± 0.5&nbsp;mm per year for the 20th century.<ref>Bindoff ''et al.'', [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5.html Chapter 5: Observations: Oceanic Climate Change and Sea Level], [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-es.html Executive summary], in {{Harvnb|IPCC AR4 WG1|2007}}.</ref> In its [[Fifth Assessment Report]], The IPCC found that recent observations of global average sea level rise at a rate of 3.2 [2.8 to 3.6] mm per year is consistent with the sum of contributions from observed thermal ocean expansion due to rising temperatures (1.1 [0.8 to 1.4] mm per year, glacier melt (0.76 [0.39 to 1.13] mm per year), Greenland ice sheet melt (0.33 [0.25 to 0.41] mm per year), Antarctic ice sheet melt (0.27 [0.16 to 0.38] mm per year), and changes to land water storage (0.38 [0.26 to 0.49] mm per year). The report had also concluded that if emissions continue to keep up with the worst case IPCC scenarios, global average sea level could rise by nearly 1m by 2100 (0.52−0.98 m from a 1986-2005 baseline). If emissions follow the lowest emissions scenario, then global average sea level is projected to rise by between 0.28−0.6 m by 2100 (compared to a 1986−2005 baseline).<ref>{{cite web|last1=Church|first1=John|last2=Clark|first2=Peter|title=Chapter 13: Sea Level Change - Final Draft Underlying Scientific-Technical Assessment|url=http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter13.pdf|website=http://www.climatechange2013.org/|publisher=IPCC Working Group I|accessdate=January 21, 2015}}</ref> == Past changes in sea level == [[File:Holocene Sea Level.png|thumb|300px|Changes in sea level during the last 9,000 years]] === The sedimentary record === [[Sediment]]ary deposits follow cyclic patterns. Prevailing theories hold that this cyclicity primarily represents the response of depositional processes to the rise and fall of sea level. The rock record indicates that in earlier eras, sea level was both much lower than today and much higher than today. Such anomalies often appear worldwide. For instance, during the depths of the last [[ice age]] 18,000 years ago when hundreds of thousands of cubic miles of ice were stacked up on the continents as glaciers, sea level was {{convert|120|m}} lower, locations that today support coral reefs were left high and dry, and coastlines were miles farther outward. During this time of very low sea level there was a dry land connection between Asia and [[Alaska]] over which humans are believed to have migrated to North America (see [[Bering Land Bridge]]).<ref>https://genographic.nationalgeographic.com/human-journey/</ref> For the past 6,000 years, the world's sea level gradually approached the current level except during marine transgressions like the [[Older Peron]]. During the previous interglacial about 120,000 years ago, sea level was for a short time about {{convert|6|m}} higher than today, as evidenced by wave-cut notches along cliffs in the [[Bahamas]]. There are also Pleistocene [[coral reef]]s left stranded about 3 metres above today's sea level along the southwestern coastline of [[West Caicos]] Island in the West Indies. These once-submerged reefs and nearby paleo-beach deposits indicate that sea level spent enough time at that higher level to allow reefs to grow (exactly where this extra sea water came from—Antarctica or Greenland—has not yet been determined). Similar evidence of geologically recent sea level positions is abundant around the world.{{Citation needed|date=December 2011}} === Estimates of past changes === See figure 11.4<ref>Anisimov ''et al.'', [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/408.htm Chapter 11: Changes in Sea Level], [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/fig11-4.htm Section 11.2.3.4: Sensitivity to climatic change], [http://www.grida.no/climate/ipcc_tar/wg1/fig11-4.htm Figure 11.4], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> in the [[IPCC Third Assessment Report|Third Assessment Report]] for a [[Sea-level curve|graph of sea-level changes]] over the past 140,000 years. * Sea level rise estimates from [[satellite altimetry]] since 1993 are in the range of 2.9–3.4&nbsp;mm/yr.<ref name="Nerem_2010"> {{cite journal | doi=10.1080/01490419.2010.491031 | title=Estimating Mean Sea Level Change from the TOPEX and Jason Altimeter Missions | year=2010 | author=Nerem | journal=Marine Geodesy | volume=33 | pages=435–446 | author2=R. S.'' | display-authors=2 | last3=Choe | first3=C. | last4=Mitchum | first4=G. T. | ref=harv}} </ref><ref name="sealevel_cu"/><ref name="sealevel_aviso"/><ref name="sealevel_csiro"/><ref name="sealevel_noaa"/> * Church and White (2006) report an acceleration of SLR since 1870.<ref name="Church L01602"/> This is a revision since 2001, when the TAR stated that measurements have detected no significant acceleration in the recent rate of sea level rise. * Based on [[tide gauge]] data, the rate of global average sea level rise during the 20th century lies in the range 0.8 to 3.3&nbsp;mm/yr, with an average rate of 1.8&nbsp;mm/yr.<ref>Anisimov ''et al.'', [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/408.htm Chapter 11: Changes in Sea Level], [http://www.grida.no/climate/ipcc_tar/wg1/422.htm#tab119 Table 11.9], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> * Recent studies of Roman wells in [[Caesarea]] and of Roman ''[[piscina]]e'' in Italy indicate that sea level stayed fairly constant from a few hundred years AD to a few hundred years ago. * Based on geological data, global average sea level may have risen at an average rate of about 0.5&nbsp;mm/yr over the last 6,000 years and at an average rate of 0.1–0.2&nbsp;mm/yr over the last 3,000 years. * Since the [[Last Glacial Maximum]] about 20,000 years ago, sea level has risen by more than 120 m (averaging 6&nbsp;mm/yr) as a result of melting of major ice sheets. A rapid rise took place between 15,000 and 6,000 years ago at an average rate of 10&nbsp;mm/yr which accounted for 90 m of the rise; thus in the period since 20,000 years BP (excluding the rapid rise from 15–6 kyr BP) the average rate was 3&nbsp;mm/yr. * A significant event was [[Meltwater pulse 1A]] (mwp-1A), when sea level rose approximately 20 m over a 500-year period about 14,200 years ago. This is a rate of about 40&nbsp;mm/yr. The primary source may have been meltwater from the [[Antarctic ice sheet]], perhaps causing the south-to-north cold pulse marked by the Southern Hemisphere [[Huelmo/Mascardi Cold Reversal]], which preceded the Northern Hemisphere [[Younger Dryas]]. Other recent studies suggest a Northern Hemisphere source for the meltwater in the [[Laurentide ice sheet]]. * Relative sea level rise at specific locations is often 1–2&nbsp;mm/yr greater or less than the global average. Along the US mid-Atlantic and Gulf Coasts, for example, sea level is rising approximately 3&nbsp;mm/yr === US tide gauge measurements === [[File:U. S. Sea Level Trends 1900-2003.gif|thumb|200px|US sea-level trends 1900–2003]] Tide gauges in the United States reveal considerable variation because some land areas are rising and some are sinking. For example, over the past 100 years, the rate of sea level rise varied from about an increase of {{convert|0.36|in|mm}} per year along the Louisiana Coast (due to land sinking), to a drop of a few inches per decade in parts of Alaska (due to [[post-glacial rebound]]). The rate of sea level rise increased during the 1993–2003 period compared with the longer-term average (1961–2003), although it is unclear whether the faster rate reflected a short-term variation or an increase in the long-term trend.<ref>{{cite web | title=Sea Level Changes| url=http://www.epa.gov/climatechange/science/recentslc.html | publisher=[[United States Environmental Protection Agency]] | accessdate=Jan 5, 2012}}</ref> One study showed no acceleration in sea level rise in US tide gauge records during the 20th century.<ref>{{cite doi|10.2112/JCOASTRES-D-10-00157.1}}</ref> However, another study found that the rate of rise for the US Atlantic coast during the 20th century was far higher than during the previous two thousand years.<ref>{{cite doi|10.1073/pnas.1015619108}}</ref> === Amsterdam sea level measurements === The longest running sea-level measurements are recorded at [[Amsterdam]], in the Netherlands—part of which (about 25%) lies beneath sea level, beginning in 1700.<ref>[http://www.pol.ac.uk/psmsl/longrecords/longrecords.html Long Records]</ref> Since 1850, the rise averaged 1.5&nbsp;mm/year. === Australian sea level change === In [[Australia]], data collected by the [[Commonwealth Scientific and Industrial Research Organisation]] (CSIRO) show the current global mean sea level trend to be 3.2&nbsp;mm/yr.,<ref>{{cite web|title=Historical Sea Level Changes|url=http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html|publisher=CSIRO|accessdate=25 April 2013}}</ref> a doubling of the rate of the total increase of about 210mm that was measured from 1880 to 2009, which reflected an average annual rise over the entire 129-year period of about 1.6&nbsp;mm/year.<ref>{{cite web|last=Neil|first=White|title=Historical Sea Level Changes|url=http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html|publisher=CSIRO|accessdate=25 April 2013}}</ref> Australian record collection has a long time horizon, including measurements by an amateur meteorologist beginning in 1837 and measurements taken from a sea-level benchmark struck on a small cliff on the Isle of the Dead<ref>{{cite journal|last=Hunter|first=John|author2=R. Coleman |author3=D. Pugh |title=The Sea Level at Port Arthur, Tasmania, from 1841 to the Present|journal=Geophysical Research Letters|date=April 2003|volume=30|issue=7|doi=10.1029/2002GL016813|accessdate=25 April 2013|bibcode = 2003GeoRL..30.1401H }}</ref> near the Port Arthur convict settlement on 1 July 1841. These records, when compared with data recorded by modern tide gauges, reinforce the recent comparisons of the historic sea level rise of about 1.6&nbsp;mm/year, with the sharp acceleration in recent decades.<ref>{{cite press release |url=http://www.austlii.edu.au/au/journals/MarStudies/2002/26.html#Heading55 |title=Landmark study confirms rising Australian sea level |publisher=CSIRO Marine and Atmospheric Research |date=2003-01-23 |accessdate=2012-07-19 }}</ref> Continuing extensive sea level data collection by Australia's [[Commonwealth Scientific and Industrial Research Organisation|(CSIRO)]] is summarized in in its finding of mean sea level trend to be 3.2&nbsp;mm/yr. As of 2003 the National Tidal Centre of the Bureau of Meteorology managed 32 tide gauges covering the entire Australian coastline, with some measurements available starting in 1880.<ref>{{cite web |url=http://www.environment.gov.au/soe/2006/publications/drs/pubs/366/co/co_03_aust_mean_sea_level_survey_2003.pdf |title=Australian Mean Sea Level Survey |year=2003 |author=National Tidal Centre |publisher=Australian Government [[Bureau of Meteorology]] |accessdate=2010-12-18 }}</ref> == Future sea-level rise == {{See also|Global climate model#Projections of future climate change|l1=Projections of future climate change|Future sea level}} ===Projections=== ==== 21st century ==== The 2007 [[IPCC Fourth Assessment Report|Fourth Assessment Report]] (IPCC 4) projected century-end sea levels using the [[Special Report on Emissions Scenarios]] (SRES). SRES developed emissions scenarios to project climate-change impacts.<ref>{{cite book | year=2009 | chapter=Global climate change | pages=22–24 | title=Global Climate Change Impacts in the United States | editor=Karl, TR, et al. | publisher=Cambridge University Press | location = 32 Avenue of the Americas, New York, NY 10013-2473, USA | isbn=978-0-521-14407-0 | url=http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/ | accessdate=2011-04-28}} </ref> The projections based on these scenarios are not predictions,<ref>IPCC AR4, [http://www.ipcc.ch/publications_and_data/ar4/wg1/en/annexessglossary-p-z.html Glossary P-Z: "Projection"], in {{Harvnb|IPCC AR4 WG1|2007}}.</ref> but reflect plausible estimates of future social and [[economic development]] (e.g., [[economic growth]], [[population projection|population level]]).<ref>Morita ''et al.'', [http://www.grida.no/climate/ipcc_tar/wg3/068.htm Chap. 2: Greenhouse Gas Emission Mitigation Scenarios and Implications], [http://www.grida.no/climate/ipcc_tar/wg3/071.htm#221 Section 2.2.1: Introduction to Scenarios], in {{Harvnb|IPCC TAR WG3|2001}}.</ref> The six SRES "marker" scenarios projected sea level to rise by {{convert|18|to|59|cm}}.<ref name="syr_3-2-1"> IPCC, [http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains3.html Topic 3], [http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains3-2-1.html Section 3.2.1: 21st century global changes], [http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf p. 45], in {{Harvnb|IPCC AR4 SYR|2007}}.</ref> Their projections were for the time period 2090–99, with the increase in level relative to average sea level over the 1980–99 period. This estimate did not include all of the possible contributions of ice sheets. More recent research from 2008 observed rapid declines in ice-mass balance from both Greenland and Antarctica, and concluded that sea-level rise by 2100 is likely to be at least twice as large as that presented by IPCC AR4, with an upper limit of about two meters.<ref name="Copenhagen Diagnosis"> {{cite journal | contribution=Copenhagen Diagnosis | author=I. Allison, N.L. Bindoff, R.A. Bindschadler, P.M. Cox, N. de Noblet, M.H. England, J.E. Francis, N. Gruber, A.M. Haywood, D.J. Karoly, G. Kaser, C. Le Quéré, T.M. Lenton, M.E. Mann, B.I. McNeil, A.J. Pitman, S. Rahmstorf, E. Rignot, H.J. Schellnhuber, S.H. Schneider, S.C. Sherwood, R.C.J. Somerville, K. Steffen, E.J. Steig, M. Visbeck, A.J. Weaver | title=The Copenhagen Diagnosis, 2009: Updating the World on the Latest Climate Science | year=2009 | contribution-url=http://www.copenhagendiagnosis.com/read/default.html | ref=harv}}</ref> A literature assessment published in 2010 by the [[US National Research Council]] described the above IPCC projections as "conservative," and summarized the results of more recent studies.<ref name=nrcpro>{{cite book | year=2010 | pages=243–250 | chapter=7 Sea Level Rise and the Coastal Environment | title=Advancing the Science of Climate Change | publisher=[http://www.nap.edu/ The National Academies Press] | location=Washington, D.C. | author=America's Climate Choices: Panel on Advancing the Science of Climate Change, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, NATIONAL RESEARCH COUNCIL OF THE NATIONAL ACADEMIES | url=http://books.nap.edu/openbook.php?record_id=12782&page=243 | isbn=978-0-309-14588-6 | accessdate=2011-06-17 | quote = (From pg 250) Even if sea-level rise were to remain in the conservative range projected by the IPCC (0.6–1.9 feet [0.18–0.59 m])—not considering potentially much larger increases due to rapid decay of the Greenland or West Antarctic ice sheets—tens of millions of people worldwide would become vulnerable to flooding due to sea-level rise over the next 50 years (Nicholls, 2004; Nicholls and Tol, 2006). This is especially true in densely populated, low-lying areas with limited ability to erect or establish protective measures. In the United States, the high end of the conservative IPCC estimate would result in the loss of a large portion of the nation's remaining coastal wetlands. The impact on the east and Gulf coasts of the United States of 3.3 feet (1 m) of sea-level rise, which is well within the range of more recent projections for the 21st century (e.g., Pfeffer et al., 2008; Vermeer and Rahmstorf, 2009), is shown in pink in [http://books.nap.edu/openbook.php?record_id=12782&page=251#p2001c3c59960251001 Figure 7.7]. Also shown, in red, is the effect of 19.8 feet (6 m) of sea-level rise, which could occur over the next several centuries if warming were to continue unabated. }} </ref> These projections ranged from {{convert|56|-|200|cm}}, based on the same period as IPCC 4. In 2011, Rignot and others projected a rise of {{convert|32|cm}} by 2050. Their projection included increased contributions from the Antarctic and Greenland ice sheets. Use of two completely different approaches reinforced the Rignot projection.<ref>{{cite journal | author = Rignot E. | coauthors = I. Velicogna, M. R. van den Broeke, A. Monaghan, and J. Lenaerts | title = Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise | journal = Geophysical Research Letters | volume = 38 | doi = 10.1029/2011GL046583 | quote = Considerable disparity remains between these estimates due to the inherent uncertainties of each method, the lack of detailed comparison between independent estimates, and the effect of temporal modulations in ice sheet surface mass balance. Here, we present a consistent record of mass balance for the Greenland and Antarctic ice sheets over the past two decades, validated by the comparison of two independent techniques over the past eight years: one differencing perimeter loss from net accumulation, and one using a dense time series of timevariable gravity. We find excellent agreement between the two techniques for absolute mass loss and acceleration of mass loss. | bibcode=2011GeoRL..3805503R | year = 2011 | issue = 5 | ref = harv}} </ref><ref name="Romm10Mar2011">{{cite web |url=http://thinkprogress.org/romm/2011/03/10/207664/jpl-greenland-antarctica-ice-sheet-mass-loss-accelerating-sea-level-rise-1-foot-by-2050/ |title=JPL bombshell: Polar ice sheet mass loss is speeding up, on pace for 1 foot sea level rise by 2050 |author=[[Joseph J. Romm|Romm, Joe]] |date=10 Mar 2011 |work=Climate Progress |publisher=Center for American Progress Action Fund |accessdate=16 April 2012}}</ref> Most recently, the Third [[National Climate Assessment]] (NCA), released May 6th, 2014, projected a sea level rise of 1 to 4 feet by 2100. Decision makers who are particularly susceptible to risk may wish to use a wider range of scenarios from 8 inches to 6.6 feet by 2100.<ref name="Sea Level Rise Key Message">{{cite web|title=Sea Level Rise Key Message Third National Climate Assessment|url=http://nca2014.globalchange.gov/report/our-changing-climate/sea-level-rise|website=National Climate Assessment|accessdate=25 June 2014}}</ref> ==== After 2100 ==== {{See also|Global climate model#Projections of future climate change|l1=Projections of future climate change|Future sea level}} [[File:Projected change in global sea level rise if atmospheric carbon dioxide concentrations were to either quadruple or double (NOAA GFDL).png|thumb|350px|alt=Refer to caption and image description|This graph shows the projected change in global sea level rise if [[atmospheric carbon dioxide]] (CO₂) concentrations were to either quadruple or double. <ref name="gfdl thermal expansion projections"> {{Include-USGov | agency=[[NOAA]] | source={{citation | author=NOAA GFDL | url=http://www.gfdl.noaa.gov/climate-impact-of-quadrupling-co2 | title=Geophysical Fluid Dynamics Laboratory - Climate Impact of Quadrupling CO₂ | publisher=NOAA GFDL | location=Princeton, NJ, USA }} }} </ref> The projection is based on several multi-century integrations of a [[Geophysical Fluid Dynamics Laboratory|GFDL]] [[global climate model|global coupled ocean-atmosphere model]]. These projections are the expected changes due to [[thermal expansion]] of sea water alone, and do not include the effect of melted continental [[ice sheet]]s. With the effect of ice sheets included, the total rise could be larger by a substantial factor.<ref name="gfdl thermal expansion projections"/> Image credit: [[NOAA]] GFDL.]] There is a widespread consensus that substantial long-term sea-level rise will continue for centuries to come.<ref name=nrccon>{{cite book | year=2010 | page=245 | chapter=7 Sea Level Rise and the Coastal Environment | title=Advancing the Science of Climate Change | publisher=[http://www.nap.edu/ The National Academies Press] | location=Washington, D.C. | author=America's Climate Choices: Panel on Advancing the Science of Climate Change, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, NATIONAL RESEARCH COUNCIL OF THE NATIONAL ACADEMIES | url=http://books.nap.edu/openbook.php?record_id=12782&page=245 | isbn=978-0-309-14588-6 | accessdate=2011-06-17}} </ref> IPCC 4 estimated that at least a partial deglaciation of the [[Greenland ice sheet]], and possibly the [[West Antarctic ice sheet]], would occur given a global average temperature increase of 1–4&nbsp;°C <!-- Do not simply put {convert} to °F here as it is not 1–4 °C above 0°C but 1–4 °C change from average --> (relative to temperatures over the years 1990–2000).<ref>IPCC AR4, [http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spm.html Summary for Policymakers], [http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spmsspm-c-15-magnitudes-of.html Section C. Current knowledge about future impacts – Magnitudes of impact] in {{Harvnb|IPCC AR4 WG2|2007}} </ref> This estimate was given about a 50% chance of being correct.<ref>IPCC AR4, [http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spmsspm-e.html Summary for Policymakers, Endbox 2. Communication of Uncertainty], in {{Harvnb|IPCC AR4 WG2|2007}}</ref> The estimated timescale was centuries to millennia, and would contribute {{convert|4|to|6|m}} or more to sea levels over this period. There is the possibility of a rapid change in glaciers, ice sheets, and hence sea level.<ref>{{cite book | year=2008 | title=U.S. Climate Change Science Program: Synthesis and Assessment Report 3.4: Abrupt Climate Change: Summary and Findings | page=2 | format=PDF | url=http://downloads.climatescience.gov/sap/sap3-4/sap3-4-brochure.pdf | publisher=US Geological Survey | location = Reston, VA | accessdate=2010-08-20}} </ref> Predictions of such a change are highly uncertain due to a lack of scientific understanding. Modeling of the processes associated with a rapid ice-sheet and glacier change could potentially increase future projections of sea-level rise. === Projected impacts === Future sea level rise could lead to potentially catastrophic difficulties for shore-based communities in the next centuries: for example, many major cities such as [[London]], [[New Orleans]], and [[New York]] <ref>{{cite web|last=Jacobson|first=Rebecca|title=Engineers Consider Barriers to Protect New York From Another Sandy|url=http://www.pbs.org/newshour/rundown/2012/11/engineers-draw-barriers-to-protect-new-york-from-another-sandy.html|publisher=PBS|accessdate=26 November 2012}}</ref> already need storm-surge defenses, and would need more if the sea level rose, though they also face issues such as [[subsidence]].<ref>[http://www.grida.no/climate/ipcc_tar/wg1/index.htm ??], in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> Sea level rise could also displace many shore-based populations: for example it is estimated that a sea level rise of just 200&nbsp;mm could create 740,000 homeless people in Nigeria.<ref>{{cite web | title=Nigeria in the Dilemma of Climate Change | author=Klaus Paehler | url=http://www.kas.de/proj/home/pub/33/2/dokument_id-11468/index.html |accessdate=2008-11-04}}</ref> [[Maldives]], [[Tuvalu]], and other low-lying countries are among the areas that are at the highest level of risk. The UN's environmental panel has warned that, at current rates, sea level would be high enough to make the Maldives uninhabitable by 2100.<ref>{{cite web | author= Megan Angelo | title=Honey, I Sunk the Maldives: Environmental changes could wipe out some of the world's most well-known travel destinations | url=http://travel.yahoo.com/p-interests-27384279;_ylc=X3oDMTFxcWIyczFpBF9TAzI3MTYxNDkEX3MDMjcxOTQ4MQRzZWMDZnAtdG9kYXltb2QEc2xrA21hbGRpdmVzLTQtMjgtMDk- | date=1 May 2009}}</ref><ref>{{cite web | author= Kristina Stefanova | title=Climate refugees in Pacific flee rising sea | url= http://www.washingtontimes.com/news/2009/apr/19/rising-sea-levels-in-pacific-create-wave-of-migran/ | date=19 April 2009}}</ref> Future sea-level rise, like the recent rise, is not expected to be globally uniform (details below). Some regions show a sea-level rise substantially more than the global average (in many cases of more than twice the average), and others a sea level fall.<ref>[http://www.grida.no/climate/ipcc_tar/wg1/432.htm ??], in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> However, models disagree as to the likely pattern of sea level change.<ref>[http://www.grida.no/climate/ipcc_tar/wg1/fig11-13.htm Fig. 11?], in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> In September 2008, the [[Delta Commission]] ([[:nl:Deltacommissie (2007)|Deltacommissie (2007)]]) presided by Dutch politician [[Cees Veerman]] advised in a report that the Netherlands would need a massive new building program to strengthen the country's water defenses against the anticipated [[effects of global warming]] for the next 190 years. This commission was created in September 2007, after the damage caused by [[Hurricane Katrina]] prompted reflection and preparations. Those included drawing up worst-case plans for evacuations. The plan included more than €100 billion (US$144 bn), in new spending through the year 2100 to take measures, such as broadening coastal [[dunes]] and strengthening sea and river [[Dyke (construction)|dikes]]. The commission said the country must plan for a rise in the North Sea up to {{convert|1.3|m}} by 2100, rather than the previously projected {{convert|0.80|m}}, and plan for a 2–4 metre (6.5–13 feet) rise by 2200.<ref>[http://www.nytimes.com/2008/09/03/news/03iht-03dutch.15877468.html "Dutch draw up drastic measures to defend coast against rising seas"]</ref> {{Main|Delta Works}} ==== Australia ==== The impact of future sea level rise on the Australian coastline can be assessed using the [http://www.sealevelrise.info/ Canute] online [[Decision Support]] Tool. === IPCC Third Assessment === {{update|[[IPCC Fourth Assessment Report]]|date=November 2013}} The results from the [[IPCC Third Assessment Report]] (TAR) sea level chapter <!-- Which chapter is that? That would be more useful info than: (convening authors [[John A. Church]] and [[Jonathan M. Gregory]]) --> are given below. {| class="wikitable" |- ! IPCC change factors 1990–2100 ! IS92a [[prediction]] ! SRES projection/ |- | Thermal expansion || 110 to 430&nbsp;mm || |- | Glaciers || 10 to 230&nbsp;mm<ref name="grida">[http://www.grida.no/climate/ipcc_tar/wg1/409.htm 409?] in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> <br /> (or 50 to 110&nbsp;mm)<ref>[http://www.grida.no/climate/ipcc_tar/wg1/434.htm#11542 ??] in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> || |- | Greenland ice || −20 to 90&nbsp;mm || |- | Antarctic ice || −170 to 20&nbsp;mm || |- | Terrestrial storage || −83 to 30&nbsp;mm || |- | Ongoing contributions from ice sheets in response to past climate change || 0 to 55&nbsp;mm || |- | Thawing of permafrost || 0 to 5&nbsp;mm || |- | Deposition of sediment || not specified || |- ! Total global-average sea level rise <br /> ''(IPCC result, not sum of above)''<ref name="grida" /> !! 110 to 770&nbsp;mm !! 90 to 880&nbsp;mm <br /> (central value of 480&nbsp;mm) |} The sum of these components indicates a rate of eustatic sea level rise (corresponding to a change in ocean volume) from 1910 to 1990 ranging from −0.8 to 2.2&nbsp;mm/yr, with a central value of 0.7&nbsp;mm/yr. The upper bound is close to the observational upper bound (2.0&nbsp;mm/yr), but the central value is less than the observational lower bound (1.0&nbsp;mm/yr), i.e., the sum of components is biased low compared to the observational estimates. The sum of components indicates an acceleration of only 0.2 (mm/yr)/century, with a range from −1.1 to +0.7 (mm/yr)/century, consistent with observational finding of no acceleration in sea-level rise during the 20th century. The estimated rate of sea-level rise from [[human impact on the environment|anthropogenic]] climate change from 1910 to 1990 (from modeling studies of thermal expansion, glaciers and ice sheets) ranges from 0.3 to 0.8&nbsp;mm/yr. It is very likely that 20th-century warming has contributed significantly to the observed sea-level rise, through the thermal expansion of sea water and the widespread loss of land ice.<ref name="grida" /> A common perception is that the rate of sea-level rise should have accelerated during the latter half of the 20th century, but [[tide gauge]] data for the 20th century show no significant acceleration. Estimates obtained are based on [[global climate model#Atmospheric vs ocean models|atmosphere-ocean general circulation models]] (abbreviated AOGCMs) for the terms directly related to anthropogenic climate change in the 20th century, i.e., thermal expansion, ice sheets, glaciers and ice caps&nbsp;... The total computed rise indicates an acceleration of only 0.2 (mm/yr)/century, with a range from −1.1 to +0.7 (mm/yr)/century, consistent with observational finding of no acceleration in sea-level rise during the 20th century.<ref name="grida_a">[http://www.grida.no/climate/ipcc_tar/wg1/426.htm#fig1110 Fig?] in {{Harvnb|IPCC TAR WG1|2001}}.{{verify source|date=September 2011}}</ref> The sum of terms not related to recent climate change is −1.1 to +0.9&nbsp;mm/yr (i.e., excluding thermal expansion, glaciers and ice caps, and changes in the ice sheets due to 20th century climate change). This range is less than the observational lower bound of sea-level rise. Hence it is very likely that these terms alone are an insufficient explanation, implying that 20th century climate change has made a contribution to 20th century sea-level rise.<ref name="grida2001"/> Recent figures of human, terrestrial impoundment came too late for the 3rd Report, and would revise levels upward for much of the 20th century. ==== Uncertainty in TAR sea-level projections ==== The different SRES emissions scenarios used for the TAR sea-level projections were not assigned probabilities, and no scenario is assumed by the IPCC to be more probable than another.<ref>Jiang ''et al.'' [http://www.grida.no/climate/ipcc_tar/wg3/068.htm Chapter 2: Greenhouse Gas Emission Mitigation Scenarios and Implications], [http://www.grida.no/climate/ipcc_tar/wg3/080.htm#2512 Section 2.5.1.2, SRES Approach to Scenario Development] in {{Harvnb|IPCC TAR WG3|2001}}.</ref> For the first part of the 21st century, the variation between the different SRES scenarios is relatively small.<ref name="Chapter 11: Changes in Sea Level">Anisimov ''et al.'', [http://www.grida.no/climate/ipcc_tar/wg1/408.htm Chapter 11: Changes in Sea Level], [http://www.grida.no/climate/ipcc_tar/wg1/431.htm Section 11.5.1.2, Projections for SRES scenarios], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> The range spanned by the SRES scenarios by 2040 is only 0.02 m or less. By 2100, this range increases to 0.18 m. Of the six illustrative SRES scenarios, A1FI gives the largest sea-level rise and B1 the smallest (see the [[Special Report on Emissions Scenarios|SRES article]] for a description of the different scenarios). For the TAR sea-level projections, uncertainty in the climate sensitivity and heat uptake of the oceans, as represented by the spread of models (specifically, [[global climate model#Atmospheric vs ocean models|atmosphere–ocean general circulation models]], or AOGCMs), is more important than the uncertainty from the choice of emissions scenario.<ref name="Chapter 11: Changes in Sea Level"/> This differs from the TAR's [[Global climate model#Projections of future climate change|projections of global warming]] (i.e., the future increase in global mean temperature), where the uncertainty in emissions scenario and climate sensitivity are comparable in size. ==== Minority uncertainties and criticisms regarding IPCC results ==== * Tide records with a rate of 180&nbsp;mm/century going back to the 19th century show no measurable acceleration throughout the late 19th and first half of the 20th century. The IPCC attributes about 60&nbsp;mm/century to melting and other eustatic processes, leaving a residual of 120&nbsp;mm of 20th-century rise to be accounted for. Global ocean temperatures by Levitus et al. are in accord with coupled ocean/atmosphere modelling of [[greenhouse effect|greenhouse]] warming, with heat-related change of 30&nbsp;mm. Melting of polar ice-sheets at the upper limit of the IPCC estimates could close the gap, but severe limits are imposed by the observed perturbations in Earth rotation. (Munk 2002) * By the time of the IPCC TAR, attribution of sea-level changes had a large unexplained gap between direct and indirect estimates of global sea-level rise. Most direct estimates from tide gauges give 1.5–2.0&nbsp;mm/yr, whereas indirect estimates based on the two processes responsible for global sea-level rise, namely mass and volume change, are significantly below this range. Estimates of the volume increase due to ocean warming give a rate of about 0.5&nbsp;mm/yr and the rate due to mass increase, primarily from the melting of continental ice, is thought to be even smaller. One study confirmed tide-gauge data is correct, and concluded there must be a continental source of 1.4&nbsp;mm/yr of fresh water. (Miller 2004) * From (Douglas 2002): "In the last dozen years, published values of 20th century GSL rise have ranged from 1.0 to 2.4&nbsp;mm/yr. In its Third Assessment Report, the IPCC discusses this lack of consensus at length and is careful not to present a best estimate of 20th century GSL rise. By design, the panel presents a snapshot of published analysis over the previous decade or so and interprets the broad range of estimates as reflecting the uncertainty of our knowledge of GSL rise. We disagree with the IPCC interpretation. In our view, values much below 2&nbsp;mm/yr are inconsistent with regional observations of sea-level rise and with the continuing physical response of Earth to the most recent episode of deglaciation." * The strong 1997–1998 El Niño caused regional and global sea-level variations, including a temporary global increase of perhaps 20&nbsp;mm. The IPCC TAR's examination of satellite trends says: "the major 1997/98 [[El Niño-Southern Oscillation]] (ENSO) event could bias the above estimates of sea-level rise and also indicate the difficulty of separating long-term trends from climatic variability".<ref name="grida_a" /> === Glacier contribution === It is well known that [[glacier]]s are subject to surges in their rate of movement with consequent melting when they reach lower altitudes and/or the sea. The contributors to Annals of Glaciology [http://www.igsoc.org/annals/], Volume 36 <ref>[http://www.igsoc.org/annals/36/ International Glaciological Society (IGS) » Annals of Glaciology, Volume 36<!-- Bot generated title -->]</ref> (2003) discussed this phenomenon extensively and it appears that slow advance and rapid retreat have persisted ''throughout the mid to late Holocene'' in nearly all of Alaska's glaciers. Historical reports of surge occurrences in Iceland's glaciers go back several centuries. Thus rapid retreat can have several other causes than CO2 increase in the atmosphere. The results from Dyurgerov show a sharp increase in the contribution of mountain and subpolar glaciers to sea-level rise since 1996 (0.5&nbsp;mm/yr) to 1998 (2&nbsp;mm/yr) with an average of about 0.35&nbsp;mm/yr since 1960.<ref>Dyurgerov, Mark. 2002. Glacier Mass Balance and Regime: Data of Measurements and Analysis. INSTAAR Occasional Paper No. 55, ed. M. Meier and R. Armstrong. Boulder, CO: Institute of Arctic and Alpine Research, University of Colorado. Distributed by National Snow and Ice Data Center, Boulder, CO. A shorter discussion is at [http://nsidc.org/sotc/sea_level.html]</ref> Of interest also is Arendt et al.,<ref>{{cite journal| last=Arendt| coauthors=et al.| journal=Science| volume=297| pages=382–386|date=July 2002 | title=Rapid Wastage of Alaska Glaciers and Their Contribution to Rising Sea Level | pmid=12130781 | doi = 10.1126/science.1072497| first1=AA| issue=5580 |bibcode = 2002Sci...297..382A| ref=harv }}</ref> who estimate the contribution of Alaskan glaciers of 0.14±0.04&nbsp;mm/yr between the mid-1950s to the mid-1990s, increasing to 0.27&nbsp;mm/yr in the middle and late 1990s. == Greenland contribution == Krabill ''et al.''<ref>{{cite journal| last=Krabill| coauthors= et al.| journal=Science| volume= 289| issue= 5478| pages= 428–430|date=21 July 2000 | pmid=10903198 | doi = 10.1126/science.289.5478.428 | title=Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning| first1=W|bibcode = 2000Sci...289..428K| ref=harv }}</ref> estimate a net contribution from [[Greenland]] to be at least 0.13&nbsp;mm/yr in the 1990s. Joughin ''et al.''<ref>{{cite journal| last=Joughin| coauthors=et al.| journal=[[Nature (journal)|Nature]]| volume= 432| pages=608–610|date=December 2004 | pmid=15577906 | doi = 10.1038/nature03130 | title=Large fluctuations in speed on Greenland's Jakobshavn Isbræ glacier| first1=I| issue=7017|bibcode = 2004Natur.432..608J| ref=harv }}</ref> have measured a doubling of the speed of [[Jakobshavn Isbræ]] between 1997 and 2003. This is Greenland's largest outlet glacier; it drains 6.5% of the ice sheet, and is thought to be responsible for increasing the rate of sea-level rise by about 0.06 millimetres per year, or roughly 4% of the 20th-century rate of sea-level increase.<ref>[http://www.spaceref.com/news/viewpr.html?pid=15611 Report shows movement of glacier has doubled speed | SpaceRef – Your Space Reference<!-- Bot generated title -->]</ref> In 2004, Rignot ''et al.''<ref name="Rignot 2004">{{cite journal| last=Rignot| coauthors=et al.| journal=Geophysical Research Letters| year=2004| volume=31| pages=L10401 | title=Rapid ice discharge from southeast Greenland glaciers| doi = 10.1029/2004GL019474| first1=E.| bibcode=2004GeoRL..3110401R| issue=10| ref=harv}}</ref> estimated a contribution of 0.04±0.01&nbsp;mm/yr to sea-level rise from southeast Greenland. Rignot and Kanagaratnam<ref>{{cite journal| last=Rignot| coauthors=Kanagaratnam| url=http://www.sciencemag.org/cgi/content/abstract/311/5763/986?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=luckman&searchid=1140284328766_4322&FIRSTINDEX=0&journalcode=sci | journal=Science| volume= 311| pages= 986–90| year= 2006 | title = Changes in the Velocity Structure of the Greenland Ice Sheet | doi = 10.1126/science.1121381 | pmid = 16484490| first1=E| issue=5763 |bibcode = 2006Sci...311..986R| ref=harv }}</ref> produced a comprehensive study and map of the [[outlet glacier]]s and basins of Greenland. They found widespread glacial acceleration below 66 N in 1996 which spread to 70 N by 2005; and that the ice sheet loss rate in that decade increased from 90 to 200 cubic km/yr; this corresponds to an extra 0.25–0.55&nbsp;mm/yr of sea level rise. In July 2005 it was reported<ref>{{cite news| url=http://news.independent.co.uk/world/environment/article301493.ece | work=[[The Independent]] | location=London | title=Melting Greenland glacier may hasten rise in sea level | first=Steve | last=Connor | date=2005-07-25 | accessdate=2010-04-30}}</ref> that the Kangerdlugssuaq glacier, on Greenland's east coast, was moving towards the sea three times faster than a decade earlier. Kangerdlugssuaq is around 1,000 m thick, 7.2&nbsp;km (4.5 [[Statute mile|miles]]) wide, and drains about 4% of the ice from the Greenland ice sheet. Measurements of Kangerdlugssuaq in 1988 and 1996 showed it moving at between 5 and 6&nbsp;km/yr (3.1–3.7 miles/yr), while in 2005 that speed had increased to 14&nbsp;km/yr (8.7 miles/yr). According to the 2004 [[Arctic Climate Impact Assessment]], climate models project that local warming in Greenland will exceed 3&nbsp;°C during this century. Also, [[ice-sheet model]]s project that such a warming would initiate the long-term melting of the ice sheet, leading to a complete melting of the [[Greenland ice sheet]] over several millennia, resulting in a global sea level rise of about seven metres.<ref>http://umcca.um.edu.my/glex2308/micellaneous/The%20Role%20Sea%20Ice%20in%20Dangerous%20Climate%20Change.pdf</ref> == Antarctic contribution == {{See also|Antarctica#Ice mass and global sea level}} On the Antarctic continent itself, the large volume of ice present stores around 70% of the world's fresh water.<ref name="howstuffworks">{{cite web|url=http://science.howstuffworks.com/question473.htm|title=How Stuff Works: polar ice caps|publisher=howstuffworks.com|accessdate=2006-02-12}}</ref> This ice sheet is constantly gaining ice from snowfall and losing ice through outflow to the sea. West Antarctica is currently experiencing a net outflow of glacial ice, which will increase global sea level over time. A review of the scientific studies looking at data from 1992 to 2006 suggested a net loss of around 50 gigatons of ice per year was a reasonable estimate (around 0.14&nbsp;mm of sea-level rise),<ref name="ShepherdWingham2007">{{cite doi|10.1126/science.1136776}}</ref> although significant acceleration of outflow glaciers in the [[Amundsen Sea Embayment]] could have more than doubled this figure for the year 2006.<ref name="RignotBamber2008">{{cite doi|10.1038/ngeo102}}</ref> East Antarctica is a cold region with a ground-base above sea level and occupies most of the continent. This area is dominated by small accumulations of snowfall which becomes ice and thus eventually seaward glacial flows. The mass balance of the [[East Antarctic Ice Sheet]] as a whole is thought to be slightly positive (lowering sea level) or near to balance.<ref name="ShepherdWingham2007" /><ref name="RignotBamber2008" /> However, increased ice outflow has been suggested in some regions.<ref name="RignotBamber2008" /><ref name="ChenWilson2008">{{cite doi|10.1016/j.epsl.2007.10.057}}</ref> In 2011 ice-penetrating radar led to the creation of the first high-resolution topographic map of one of the last uncharted regions of Earth: the Aurora Subglacial Basin, an immense ice-buried lowland in East Antarctica larger than Texas. The map reveals some of the largest fjords or ice cut channels on Earth. Because the basin lies kilometres below sea level, seawater could penetrate beneath the ice, causing portions of the ice sheet to collapse and float off to sea. The map is expected to improve models of ice sheet dynamics.<ref>[http://www.sciencedaily.com/releases/2011/06/110601134253.htm New map reveals giant fjords beneath East Antarctic ice sheet<!-- Bot generated title -->]</ref> Sheperd et al. 2012, found that different satellite methods were in good agreement and combing methods leads to more certainty with East Antarctica, West Antarctica, and the Antarctic Peninsula changing in mass by +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes per year.<ref>[http://www.sciencemag.org/content/338/6111/1183 Sheperd et al 2012 A Reconciled Estimate of Ice-Sheet Mass Balance]</ref> == Effects of snowline and permafrost == The snowline altitude is the altitude of the lowest elevation interval in which minimum annual snow cover exceeds 50%. This ranges from about 5,500 metres above sea-level at the equator down to sea level at about 65° N&S latitude, depending on regional temperature amelioration effects. Permafrost then appears at sea level and extends deeper below sea-level pole-wards. The depth of permafrost and the height of the ice-fields in both Greenland and Antarctica means that they are largely invulnerable to rapid melting. Greenland Summit is at 3,200 metres, where the average annual temperature is minus 32&nbsp;°C. So even a projected 4&nbsp;°C rise in temperature leaves it well below the [[melting point]] of ice. Frozen Ground 28, December 2004, has a very significant map of permafrost affected areas in the Arctic. The continuous permafrost zone includes all of Greenland, the North of Labrador, NW Territories, Alaska north of Fairbanks, and most of NE Siberia north of Mongolia and Kamchatka. Continental ice above permafrost is very unlikely to melt quickly. As most of the Greenland and Antarctic ice sheets lie above the snowline and/or base of the permafrost zone, they cannot melt in a timeframe much less than several millennia; therefore they are unlikely to contribute significantly to sea-level rise in the coming century. === Polar ice === The sea level will rise above its current level if more polar ice melts. However, compared to the heights of the ice ages, today there are very few continental ice sheets remaining to be melted. It is estimated that Antarctica, if fully melted, would contribute more than 60 metres of sea level rise, and Greenland would contribute more than 7 metres. Small glaciers and ice caps on the margins of Greenland and the Antarctic Peninsula might contribute about 0.5 metres. While the latter figure is much smaller than for Antarctica or Greenland it could occur relatively quickly (within the coming century) whereas melting of Greenland would be slow (perhaps 1,500 years to fully deglaciate at the fastest likely rate) and Antarctica even slower.<ref>Anisimov ''et al.'', [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/408.htm Chapter 11. Changes in Sea Level], [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/412.htm Section 11.2.1.2: Models of thermal expansion], [http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/412.htm#tab113 Table 1.3], in {{Harvnb|IPCC TAR WG1|2001}}.</ref> However, this calculation does not account for the possibility that as meltwater flows under and lubricates the larger ice sheets, they could begin to move much more rapidly towards the sea.<ref>{{cite journal| url = http://www.sciencemag.org/cgi/content/abstract/297/5579/218 | title=Surface Melt-Induced Acceleration of Greenland Ice-Sheet Flow | author=Zwally H.J. | journal = Science | volume = 297 | pages = 218–222 | doi = 10.1126/science.1072708 | year= 2002 | pmid = 12052902| issue = 5579 | bibcode=2002Sci...297..218Z| display-authors = 1| last2 = Abdalati| first2 = W| last3 = Herring| first3 = T| last4 = Larson| first4 = K| last5 = Saba| first5 = J| last6 = Steffen| first6 = K| ref = harv}}</ref><ref>{{cite web | url = http://www.gsfc.nasa.gov/topstory/20020606greenland.html | title=Greenland Ice Sheet flows faster during summer melting | date = 2006-06-02 | publisher = Goddard Space Flight Center (press release) }}</ref> In 2002, Rignot and Thomas<ref>{{cite journal| last=Rignot| coauthors=Thomas| journal=Science| volume=297| pages=1502–1506| year= 2002 | pmid=12202817 | doi = 10.1126/science.1073888 | title=Mass Balance of Polar Ice Sheets| first1=E| issue=5586|bibcode = 2002Sci...297.1502R| ref=harv }}</ref> found that the West Antarctic and Greenland ice sheets were losing mass, while the East Antarctic ice sheet was probably in balance (although they could not determine the sign of the mass balance for The East Antarctic ice sheet). Kwok and Comiso (''J. Climate'', v15, 487–501, 2002) also discovered that temperature and pressure anomalies around West Antarctica and on the other side of the Antarctic Peninsula correlate with recent [[El Niño|Southern Oscillation]] events. In 2004 Rignot et al.<ref name="Rignot 2004"/> estimated a contribution of 0.04 ± 0.01&nbsp;mm/yr to sea level rise from South East Greenland. In the same year, Thomas et al.<ref>{{cite journal| last=Thomas| coauthors=et al.| year= 2004| journal=Science| volume=306| pages= 255–258 | pmid=15388895 | doi = 10.1126/science.1099650 | title=Accelerated Sea-Level Rise from West Antarctica| first1=R| issue=5694|bibcode = 2004Sci...306..255T| ref=harv }}</ref> found evidence of an accelerated contribution to sea level rise from West Antarctica. The data showed that the Amundsen Sea sector of the [[West Antarctic Ice Sheet]] was discharging 250 cubic kilometres of ice every year, which was 60% more than precipitation accumulation in the [[drainage basin|catchment]] areas. This alone was sufficient to raise sea level at 0.24&nbsp;mm/yr. Further, thinning rates for the glaciers studied in 2002–03 had increased over the values measured in the early 1990s. The [[bedrock]] underlying the glaciers was found to be hundreds of metres deeper than previously known, indicating exit routes for ice from further inland in the Byrd Subpolar Basin. Thus the West Antarctic ice sheet may not be as stable as has been supposed. In 2005 it was reported that during 1992–2003, East Antarctica thickened at an average rate of about 18&nbsp;mm/yr while West Antarctica showed an overall thinning of 9&nbsp;mm/yr. associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by 0.12 ± 0.02&nbsp;mm/yr.<ref>{{cite journal| last=Davis| journal=Science|date=24 June 2005| doi=10.1126/science.1110662| pages= 1898–1901| pmid=15905362| volume=308| issue= 5730| title=Snowfall-Driven Growth in East Antarctic Ice Sheet Mitigates Recent Sea-Level Rise| first=Curt H.| coauthors=Yonghong Li, Joseph R. McConnell, Markus M. Frey, Edward Hanna|bibcode = 2005Sci...308.1898D| ref=harv }}</ref> == Effects of sea-level rise == Based on the projected increases stated above, the IPCC TAR WGII report (''Impacts, Adaptation Vulnerability'') notes that current and future climate change would be expected to have a number of impacts, particularly on [[coast]]al systems.<ref>{{Harvnb|IPCC TAR WG1|2001}}.{{page needed|date=October 2011}}</ref> Such impacts may include increased [[coastal erosion]], higher [[storm surge|storm-surge]] flooding, inhibition of [[primary production]] processes, more extensive coastal inundation, changes in surface [[water quality]] and groundwater characteristics, increased loss of property and coastal habitats, increased flood risk and potential loss of life, loss of non-monetary cultural resources and values, impacts on agriculture and [[aquaculture]] through decline in soil and water quality, and loss of tourism, recreation, and transportation functions. There is an implication that many of these impacts will be detrimental—especially for the three-quarters of the world's poor who depend on agriculture systems.<ref>"Climate Shocks: Risk and Vulnerability in an Unequal World." Human Development report 2007/2008. hdr.undp.org/media/hdr_20072008_summary_english.pdf</ref> The report does, however, note that owing to the great diversity of coastal environments; regional and local differences in projected relative sea level and climate changes; and differences in the resilience and adaptive capacity of [[ecosystem]]s, sectors, and countries, the impacts will be highly variable in time and space. Statistical data on the human impact of sea-level rise is scarce. A study in the April, 2007 issue of ''Environment and Urbanization'' reports that 634 million people live in coastal areas within {{convert|30|ft|m}} of sea level. The study also reported that about two thirds of the world's cities with over five million people are located in these low-lying coastal areas. The IPCC report of 2007 estimated that accelerated melting of the Himalayan ice caps and the resulting rise in sea levels would likely increase the severity of flooding in the short term during the rainy season and greatly magnify the impact of tidal storm surges during the cyclone season. A sea-level rise of just 400&nbsp;mm in the Bay of Bengal would put 11 percent of the Bangladesh's coastal land underwater, creating 7–10 million [[climate refugee]]s. === Island nations === IPCC assessments suggest that deltas and small island states are particularly vulnerable to sea-level rise caused by both thermal expansion and ocean volume. Sea level changes have not yet been conclusively proven to have directly resulted in environmental, humanitarian, or economic losses to small island states, but the IPCC and other bodies have found this a serious risk scenario in coming decades.<ref>[http://rs.resalliance.org/2006/06/02/future-oceans-warming-up-rising-high-turning-sour/ The Future Oceans – Warming Up, Rising High, Turning Sour<!-- Bot generated title -->]</ref> Many media reports have focused on the island nations of the Pacific, notably the Polynesian islands of [[Tuvalu]], which based on more severe flooding events in recent years, were thought to be "sinking" due to sea level rise.<ref>{{cite news| last=Levine| first= Mark|date=December 2002| title=Tuvalu Toodle-oo| publisher= Outside Magazine| url=http://www.outsideonline.com/adventure-travel/australia-pacific/Tuvalu-Toodle-oo.html| accessdate=2005-12-19}}</ref> A scientific review in 2000 reported that based on [[University of Hawaii]] gauge data, Tuvalu had experienced a negligible increase in sea level of 0.07&nbsp;mm a year over the past two decades, and that [[ENSO]] had been a larger factor in Tuvalu's higher tides in recent years.<ref name="autogenerated1">{{cite news| last=Patel| first= Samir S.| date=April 5, 2006| title=A Sinking Feeling| publisher=Nature| url=http://www.nature.com/nature/journal/v440/n7085/full/440734a.html| accessdate=2007-11-15}}</ref> A subsequent study by John Hunter from the University of Tasmania, however, adjusted for ENSO effects and the movement of the gauge (which was thought to be sinking). Hunter concluded that Tuvalu had been experiencing sea-level rise of about 1.2&nbsp;mm per year.<ref name="autogenerated1" /><ref>{{cite news| last=Hunter| first=J.A.| date=August 12, 2002| title=A Note on Relative Sea Level Rise at Funafuti, Tuvalu| url=http://staff.acecrc.org.au/~johunter/tuvalu.pdf|format=PDF}}</ref> The recent more frequent flooding in Tuvalu may also be due to an erosional loss of land during and following the actions of 1997 cyclones Gavin, Hina, and Keli.<ref>{{cite news| last=Field| first= Michael J.|date=December 2001| title=Sea Levels Are Rising| publisher=Pacific Magazine| url=http://www.pacificislands.cc/pm122001/pmdefault.php?urlarticleid=0009| accessdate=2005-12-19 |archiveurl = http://web.archive.org/web/20051218040610/http://www.pacificislands.cc/pm122001/pmdefault.php?urlarticleid=0009 <!-- Bot retrieved archive --> |archivedate = 2005-12-18}}</ref> Besides the issues that flooding brings (soil salinisation,&nbsp;...) for these islands states, the islands states themselves would also become dissolved over time, as the islands becomes uninhabitable or becomes completely submerged by the sea. Once this happens, all rights on the surrounding area (sea) are removed. This area can be huge as rights extend to a radius of 224 nautical miles (414&nbsp;km) around the entire island state. Any resources (fossil oil, minerals, metals,&nbsp;...) within this area can be freely dug up by anyone and sold without needing to pay any commission to the (now dissolved) island state.<ref>{{cite book|trans_title=Sea borders and rising sea levels: international law considerations about the effects of rising sea levels on borders at sea: speech, pronounced with the acceptance of the post of professor in international law at the University of Utrecht on Thursday, April 13th, 1989 |title=Zeegrenzen en zeespiegelrijzing : volkenrechtelijke beschouwingen over de effecten van het stijgen van de zeespiegel op grenzen in zee : rede, uitgesproken bij de aanvaarding van het ambt van hoogleraar in het volkenrecht aan de Rijksuniversiteit te Utrecht op donderdag 13 april 1989 |author=Alfred Henry Adriaan Soons |year=1989 |publisher=Kluwers |language=Dutch |isbn=978-90-268-1925-4 }}</ref> Numerous options have been proposed that would assist island nations to [[Adaptation to global warming|adapt]] to rising sea level.<ref>{{cite web | title=Policy Implications of Sea Level Rise: The Case of the Maldives | work=Proceedings of the Small Island States Conference on Sea Level Rise. November 14–18, 1989. [[Malé]], [[Republic of Maldives]]. Edited by Hussein Shihab | url=http://papers.risingsea.net/Maldives/Small_Island_States_3.html| accessdate=2007-01-12 }}</ref> ===Cities=== {{Main|List of cities impacted by current sea level rise}} [[File:Major cities threatened by sea level rise.png|thumb|right|200px|Map of major cities of the world most vulnerable to sea level rise]] [[Miami]] has been listed as "the number-one most vulnerable city worldwide" in terms of potential damage to property from storm-related flooding and sea-level rise.<ref name=RS62013>{{cite news|title=Goodbye, Miami|url=http://www.rollingstone.com/politics/news/why-the-city-of-miami-is-doomed-to-drown-20130620|accessdate=June 21, 2013|newspaper=Rolling Stone|date=June 20, 2013|author=Jeff Goodell|quote=The Organization for Economic Co-operation and Development lists Miami as the number-one most vulnerable city worldwide in terms of property damage, with more than $416 billion in assets at risk to storm-related flooding and sea-level rise.}}</ref> == Satellite sea level measurement == {{Multiple image|direction=vertical|align=right|image1=Global_Mean_Sea_Level.svg|image2=NOAA_sea_level_trend_1993_2010.png|width=250|caption1=Satellite Measurement of Sea Level.|caption2=1993–2012 Sea level trends from [[satellite altimetry]].}} Current rates of sea level rise from [[satellite altimetry]] have been estimated in the range of 2.9–3.4 ± 0.4–0.6&nbsp;mm per year for 1993–2010.<ref name="Nerem_2010"/><ref name="sealevel_cu"/><ref name="sealevel_aviso"/><ref name="sealevel_csiro"/><ref name="sealevel_noaa"/> This exceeds those from tide gauges. It is unclear whether this represents an increase over the last decades; variability; true differences between satellites and tide gauges; or problems with satellite [[calibration]].<ref name="grida_a" /> Knowing the current altitude of a satellite which can measure sea level to a precision of about 20 millimetres (e.g. the [[Topex/Poseidon]] system) is primarily complicated by [[orbital decay]] and the difference between the assumed orbit and the earth [[geoid]].<ref>http://ibis.grdl.noaa.gov/SAT/pubs/papers/2001_Cheney_Encycl.pdf</ref> This problem is partially corrected by regular re-calibration of satellite altimeters from land stations whose height from MSL is known by surveying. Over water, the height is calibrated from tide gauge data which is needed to correct for tides and atmospheric effects on sea level.{{Citation needed|date=February 2011}} === Individual studies === Ablain ''et al.'' (2008) looked at trends in mean sea level (MSL).<ref name=ablain> {{cite journal | last=Ablain | first=M. | coauthors=A. Cazenave, G. Valladeau, S. Guinehut | title=A new assessment of the error budget of global mean sea level rate estimated by satellite altimetry over 1993–2008 | journal=Ocean Science | date=17 June 2009 | volume=5 | doi=10.5194/os-5-193-2009 | url=http://www.ocean-sci.net/5/193/2009/os-5-193-2009.pdf | issue=2 | page=193 | ref=harv}} </ref>{{Rp|194–195}} A global MSL curve was plotted using data for the 1993–2008 period. Their estimates for mean rate of sea level rise over this time period was 3.11&nbsp;mm per year. A correction was applied to this resulting in a higher estimate of 3.4&nbsp;mm per year. Over the 2005 to 2008 time period, the MSL rate was estimated to be 1.09&nbsp;mm per year. This is a reduction of 60% on the rate observed between 1993 and 2005.<ref name=ablain/>{{Rp|193}} MSL was also plotted using data between the years 1994 and 2007.<ref name=ablain/>{{Rp|194–195}} Their data for this time period show two peaks ([[maxima and minima|maxima]]) in MSL rates for the years 1997 and 2002. These maxima very likely reflected the influence of the [[El Niño-Southern Oscillation|ENSO]] on MSL. Using the 1994–2007 MSL data, they estimated MSL rates using [[moving average|moving windows]] of three and five years. Lower rates were observed during [[La Niña]] events in 1999 and 2007. They concluded that the recently observed reduction in the MSL rate was likely to be real, since it coincided with an exceptionally strong La Niña event. Preliminary analyses suggested that an acceleration of the MSL trend would likely occur in relationship with the end of the 2007–08 La Niña event.<ref name=ablain/>{{Rp|200}}<ref>See also: {{cite web | date=2011-07-19 | author=CUSLRG | url = http://sealevel.colorado.edu/content/global-mean-sea-level-time-series-seasonal-signals-removed | title = 2011_rel2: Global Mean Sea Level Time Series (seasonal signals removed) | publisher = CU Sea Level Research Group (CUSLRG). Colorado Center for Astrodynamics Research at the University of Colorado at Boulder | accessdate = 2011-02-10}} "Although the latest Jason-2 GMSL estimates (cycles 95–102) are well below the trend line, most likely due to the recent La Nina (we plan to add a sea level/ENSO comparison page shortly), the rate increased slightly from 3.1 to 3.2 mm/yr due to the improvements to the TOPEX SSB model and replacement of the classical IB correction with the improved DAC correction, as noted above"</ref> White (2011) reported measurements of near-global sea level made using satellite altimeters.<ref name="sealevel_csiro">{{cite web | author=White, N. | date=2011-07-29 | url = http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html | title = CSIRO Global Mean Sea Level Estimate | publisher = Commonwealth Scientific and Industrial Research Organisation (CSIRO) / Wealth from Oceans National Research Flagship and the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) | accessdate = 2011-07-29}} </ref> Over the time period January 1993 to April 2011, these data show a steady increase in global mean sea level (GMSL) of around 3.2&nbsp;mm per year, with a range of plus or minus 0.4&nbsp;mm per year. This is 50% larger than the average rate observed over the 20th century. White (2011) was, however, unsure of whether or not this represented a long-term increase in the rate. The ''[[Centre National d'Etudes Spatiales]]''/''Collecte Localisation Satellites'' (CNES/CLS, 2011) reported on the estimated increase in GMSL between 1993 and 2011.<ref name="sealevel_aviso"> {{cite web | author=CNES/CLS | year=2011 | url = http://www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/index.html | title = AVISO Global Mean Sea Level Estimate | publisher = ''[[Centre National d'Etudes Spatiales]]''/''Collecte Localisation Satellites'' (CNES/CLS): Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) | accessdate = 2011-07-29}} </ref> Their estimate was an increase of 3.22&nbsp;mm per year, with an error range in this [[trend estimation|trend]] (i.e., the slope over the 1993 to 2011 time period) of approximately 0.6&nbsp;mm per year. The CU Sea Level Research Group (CUSLRG, 2011) estimated the rate of GMSL between 1993 and 2011.<ref name="sealevel_cu"> {{cite web | date=2011-07-19 | author=CUSLRG | url = http://sealevel.colorado.edu/content/global-mean-sea-level-time-series-seasonal-signals-removed | title = 2011_rel2: Global Mean Sea Level Time Series (seasonal signals removed) | publisher = CU Sea Level Research Group (CUSLRG). Colorado Center for Astrodynamics Research at the University of Colorado at Boulder | accessdate = 2011-02-10}} </ref> The rate was estimated at 3.2&nbsp;mm per year, with a range of plus or minus 0.4&nbsp;mm per year. The Laboratory for Satellite Altimetry (LSA, 2011) estimated the trend in GMSL over the time period 1992 to 2011.<ref name="sealevel_noaa"> {{cite web | author=LSA | date=2011-03-16 | url = http://www.star.nesdis.noaa.gov/sod/lsa/SeaLevelRise/LSA_SLR_timeseries_global.php | title = Laboratory for Satellite Altimetry / Sea level rise | publisher = [[NOAA]]: National Environmental Satellite, Data, and Information Service (NESDIS), Satellite Oceanography and Climatology Division, Laboratory for Satellite Altimetry (LSA) | accessdate = 2011-07-29}}</ref> Their estimate was a trend of 2.9&nbsp;mm per year, with a range of plus or minus 0.4&nbsp;mm per year. According to the LSA (2011): "[the] estimates of sea level rise do not include glacial isostatic adjustment effects on the geoid, which are modeled to be +0.2 to +0.5 mm/year when globally averaged." == See also == {{Portal|Global warming|Energy|Renewable energy|Sustainable development|Environment}} * [[8.2 kiloyear event]] * [[Antarctic Cold Reversal]] * [[Carbon cycle]] * [[Coastal Development Hazards|Coastal Development]] * [[Coastal sediment supply]] * [[Drawdown (hydrology)]] * [[Effects of global warming on oceans]] * [[Fossil water]] (aka paleowater) * [[Hydrosphere]] * [[Islands First]] * [[Lists of environmental topics]] * [[Older Peron|Older Peron transgression]] * [[Overdrafting]] * [[Retreat of glaciers since 1850]] * [[Standard sea level]] * [[Transgression (geology)]] * [[Water cycle]] * [[Long period tide]] {{Clear}} == Notes == {{Reflist|30em}} == References == * {{citation |year = 2007 |author = Ipcc ar4 wg1 |author-link = IPCC |title = Climate Change 2007: The Physical Science Basis |series = Contribution of Working Group I to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = Solomon, S.; Qin, D.; Manning, M.; Chen, Z.; Marquis, M.; Averyt, K.B.; Tignor, M.; and Miller, H.L. |publisher = Cambridge University Press |url = http://www.ipcc.ch/publications_and_data/ar4/wg1/en/contents.html |isbn = 978-0-521-88009-1 }} (pb: {{ISBNT|978-0-521-70596-7}}). * {{citation |year = 2007 |author = Ipcc ar4 wg2 |author-link = IPCC |title = Climate Change 2007: Impacts, Adaptation and Vulnerability |series = Contribution of Working Group II to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = Parry, M.L.; Canziani, O.F.; Palutikof, J.P.; van der Linden, P.J.; and Hanson, C.E. |publisher = Cambridge University Press |url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/contents.html |isbn = 978-0-521-88010-7 }} (pb: {{ISBNT|978-0-521-70597-4}}). * {{citation |year = 2007 |author = Ipcc ar4 wg3 |author-link = IPCC |title = Climate Change 2007: Mitigation of Climate Change |series = Contribution of Working Group III to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = Metz, B.; Davidson, O.R.; Bosch, P.R.; Dave, R.; and Meyer, L.A. |publisher = Cambridge University Press |url = http://www.ipcc.ch/publications_and_data/ar4/wg3/en/contents.html |isbn = 978-0-521-88011-4 }} (pb: {{ISBNT|978-0-521-70598-1}}). * {{citation |year = 2007 |author = Ipcc ar4 syr |author-link = IPCC |title = Climate Change 2007: Synthesis Report |series = Contribution of Working Groups I, II and III to the [[IPCC Fourth Assessment Report|Fourth Assessment Report]] of the Intergovernmental Panel on Climate Change |editors = Core Writing Team; Pachauri, R.K; and Reisinger, A. |publisher = IPCC |url= http://www.ipcc.ch/publications_and_data/ar4/syr/en/contents.html |isbn = 92-9169-122-4 }}. * {{citation |year = 2001 |author = Ipcc tar wg1 |author-link = IPCC |title = Climate Change 2001: The Scientific Basis |series = Contribution of Working Group I to the [[IPCC Third Assessment Report|Third Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = Houghton, J.T.; Ding, Y.; Griggs, D.J.; Noguer, M.; van der Linden, P.J.; Dai, X.; Maskell, K.; and Johnson, C.A. |publisher = Cambridge University Press |url = http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg1/index.htm |isbn = 0-521-80767-0 }} (pb: {{ISBNT|0-521-01495-6}}). * {{citation |year = 2001 |author = Ipcc tar wg2 |author-link = IPCC |title = Climate Change 2001: Impacts, Adaptation and Vulnerability |series = Contribution of Working Group II to the [[IPCC Third Assessment Report|Third Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = McCarthy, J. J.; Canziani, O. F.; Leary, N. A.; Dokken, D. J.; and White, K. S. |publisher = Cambridge University Press |url = http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg2/index.htm |isbn = 0-521-80768-9 }} (pb: {{ISBNT|0-521-01500-6}}). * {{citation |year = 2001 |author = Ipcc tar wg3 |author-link = IPCC |title = Climate Change 2001: Mitigation |series = Contribution of Working Group III to the [[IPCC Third Assessment Report|Third Assessment Report]] of the Intergovernmental Panel on Climate Change |editor = Metz, B.; Davidson, O.; Swart, R.; and Pan, J. |publisher = Cambridge University Press |url = http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_tar/wg3/index.htm |isbn = 0-521-80769-7 }} (pb: {{ISBNT|0-521-01502-2}}). == Further reading == <references group="note"/> {{Refbegin|2}} *{{cite web|title=Sea Level Rise Key Message|url=http://nca2014.globalchange.gov/report/our-changing-climate/sea-level-rise|website=Third National Climate Assessment|accessdate=25 June 2014}} * {{cite journal | author=Byravan, S.; Rajan, S. C. | title=The ethical implications of sea-level rise due to climate change | journal=Ethics and International Affairs | volume=24 | year=2010 | pages=239–60 | doi=10.1111/j.1747-7093.2010.00266.x | issue=3 | ref=harv}} * {{cite journal | author=[[Anny Cazenave|Cazenave, A.]]; Nerem, R. S. | title=Present-day sea level change: Observations and causes | journal=Rev. Geophys | volume=42 | year=2004 | pages=RG3001 | doi = 10.1029/2003RG000139 | bibcode=2004RvGeo..42.3001C | issue=3 | ref=harv}} * {{cite book | author=Emery, K.O., and D. G. Aubrey | title=Sea levels, land levels, and tide gauges | location=New York | publisher=Springer-Verlag | year=1991 | isbn=0-387-97449-0}} * {{cite web | title=Sea Level Variations of the United States 1854–1999 | work=NOAA Technical Report NOS CO-OPS 36 | url=http://co-ops.nos.noaa.gov/publications/techrpt36doc.pdf | accessdate=20 February 2005|format=PDF}} * {{cite journal | author=Clark, P. U., Mitrovica, J. X., Milne, G. A. & Tamisiea | title=Sea-Level Fingerprinting as a Direct Test for the Source of Global Meltwater Pulse 1A | journal=Science | volume=295 | year=2002 | pages=2438–2441 | pmid=11896236 | issue=5564 | doi=10.1126/science.1069017|bibcode = 2002Sci...296..553B | ref=harv }} * {{cite journal | author=Eelco J. Rohling, Robert Marsh, Neil C. Wells, Mark Siddall and Neil R. Edwards | title=Similar meltwater contributions to glacial sea level changes from Antarctic and northern ice sheets | journal=Nature | volume=430 | issue=August 26 | year=2004 | pages=1016–1021 |doi=10.1038/nature02859 | pmid=15329718|bibcode = 2004Natur.430.1016R | ref=harv }} * {{cite journal | author=[[Walter Munk]] | title=Twentieth century sea level: An enigma | journal=Geophysics | volume=99 | issue=10 | year=2002 | pages=6550–6555 | ref=harv | doi=10.1073/pnas.092704599}} * {{cite journal | author=Menefee, Samuel Pyeatt | title=Half Seas Over: The Impact of Sea Level Rise on International Law and Policy | journal=U.C.L.A. Journal of Environmental Law & Policy | volume=9 | issue= | year=1991 | pages=175–218 | ref=harv}} * {{cite journal | author=Laury Miller and Bruce C. Douglas | title=Mass and volume contributions to twentieth-century global sea level rise | journal=Nature | volume=428 | year=2004 | pages=406–409 | doi=10.1038/nature02309 | pmid=15042085 | issue=6981|bibcode = 2004Natur.428..406M | ref=harv }} * {{cite journal | author=Bruce C. Douglas and W. Richard Peltier | title=The Puzzle of Global Sea-Level Rise | url=http://www.aip.org/pt/vol-55/iss-3/p35.html | accessdate=24 March 2005 | journal=[[Physics Today]] | volume=55 | issue=3 | year=2002 | pages=35–41 | doi=10.1063/1.1472392 |archiveurl = http://web.archive.org/web/20050213165850/http://www.aip.org/pt/vol-55/iss-3/p35.html <!-- Bot retrieved archive --> |archivedate = 13 February 2005|bibcode = 2002PhT....55c..35D | ref=harv }} * {{cite journal|author=B. C. Douglas|journal=J. Geophys. Res.| volume=7| issue=c8| page=12699| year=1992| title=Global sea level acceleration| doi=10.1029/92JC01133| bibcode=1992JGR....9712699D|ref=harv}} * {{cite book |author=Warrick, R. A., C. L. Provost, M. F. Meier, J. Oerlemans, and P. L. Woodworth |chapter=Changes in sea level |editor=Houghton, John Theodore |title=Climate Change 1995: The Science of Climate Change |publisher=Cambridge University Press |location=Cambridge, UK |year=1996 |pages=359–405 |isbn=0-521-56436-0 }} * {{cite journal|author=R. Kwok, J. C. Comiso|journal=Journal of Climate| volume=15| issue=5| pages=487–501| year=2002| title=Southern Ocean Climate and Sea Ice Anomalies Associated with the Southern Oscillation| url = http://rkwok.jpl.nasa.gov/publications/Kwok.2002c.JCL.pdf | doi=10.1175/1520-0442(2002)015<0487:SOCASI>2.0.CO;2|format=PDF|bibcode = 2002JCli...15..487K|issn=1520-0442|ref=harv }} * Colorado Center for Astrodynamics Research, "[http://sealevel.colorado.edu/ Mean Sea Level]" Accessed December 19, 2005 * Fahnestock, Mark (December 4, 2004), "[http://www.spaceref.com/news/viewpr.html?pid=15611 Report shows movement of glacier has doubled speed]", [[University of New Hampshire]] press release. Accessed December 19, 2005 *{{cite journal |author=Leuliette, E.W., R.S. Nerem, and G.T. Mitchum |title=Calibration of TOPEX/Poseidon and Jason Altimeter Data to Construct a Continuous Record of Mean Sea Level Change |journal=Marine Geodesy |volume=27 |issue=1–2 |year=2004 |ref=harv}} * National Snow and Ice Data Center (March 14, 2005), "[http://nsidc.org/sotc/sea_level.html Is Global Sea Level Rising?]". Accessed December 19, 2005 * {{cite web | title=IPCC again | author=INQUA commission on Sea Level Changes and Coastal Evolution | url=http://www.pog.su.se/sea/HP-14.+IPCC-3.pdf | accessdate=2004-07-25 |format=PDF |archiveurl = http://web.archive.org/web/20040725130615/http://www.pog.su.se/sea/HP-14.+IPCC-3.pdf |archivedate = 2004-07-25}} * {{cite news | title=Independent Online Edition | url=http://news.independent.co.uk/world/environment/article301493.ece | accessdate=2005-12-19 | work=The Independent | location=London | first=Steve | last=Connor | date=2005-07-25}} * {{cite web | title=Address by his Excellency Mr. Maumoon Abdul Gahoom, President of the Republic of Maldives, at thenineteenth special session of the United Nations General Assembly for the purpose of an overall review and appraisal of theimplementation of agenda 21 – June 24, 1997 | author=[[Maumoon Abdul Gayoom]] | url=http://www.un.int/maldives/ungass.htm | accessdate=2006-01-06 }} * Pilkey, Orrin and Robert Young, ''The Rising Sea,'' Shearwater, July 2009 ISBN 978-1-59726-191-3 *{{cite journal|last=Douglas|first=Bruce C.|title=Global sea level change: Determination and interpretation|journal=[[Reviews of Geophysics]] |year=1995|volume=33|pages=1425–1432|doi=10.1029/95RG00355|bibcode = 1995RvGeo..33.1425D }} {{Refend}} == External links == * [http://nca2014.globalchange.gov/report/our-changing-climate/sea-level-rise Third National Climate Assessment Sea Level Rise Key Message] * {{cite web|url=http://sealevel.colorado.edu/|title=University of Colorado at Boulder Sea Level Change}} * [http://www.csc.noaa.gov/digitalcoast/_/pdf/SLC_Technical_Considerations_Document.pdf Technical Considerations for Use of Geospatial Data in Sea Level Change Mapping and Assessment] NOAA Technical Report NOS 2010–01 * [http://www.csc.noaa.gov/digitalcoast/publications/slcScenarios Incorporating Sea Level Change Scenarios at the Local Level] Outlines eight steps a community can take to develop site-appropriate scenarios *[http://www.sciencenews.org/view/generic/id/341723/title/East_Coast_faces_faster_sea_level_rise ''East Coast faces faster sea level rise; Cities from North Carolina to Massachusetts see waters rising more rapidly''] July 28, 2012; Vol.182 #2 (p.&nbsp;17) [[Science News]] *{{cite web | title = Climate change threatening the Southern Ocean | publisher=CSIRO | url = http://csiro.au/multimedia/Climate-change-threat-to-Southern-Ocean.html }} * [http://www.cmar.csiro.au/sealevel Sea Level Rise:Understanding the past – Improving projections for the future] * [http://papers.ssrn.com/sol3/papers.cfm?abstract_id=950329 Providing new homes for climate exiles] Sujatha Byravan and Sudhir Chella Rajan, 2006 * [http://web.archive.org/web/20110726071526/http://www.futureocean.org/english/research-areas/marine-resources-and-risks/sea-level-rise-and-coasts-at-risk/facts/ Sea Level Rise] – [[German Universities Excellence Initiative#Winners: Clusters of Excellence|Cluster of Excellence]] "Future Ocean", [[University of Kiel]] * [http://stephenschneider.stanford.edu/Publications/PDF_Papers/MornerEtAl2004.pdf New perspectives for the future of the Maldives] Nils-Axel Mörner, Michael Tooley, Göran Possnert, 2004 * {{cite web | title=Physical Agents of Land Loss: Relative Sea Level | work=An Overview of Coastal Land Loss: With Emphasis on the Southeastern United States |publisher=[[US Geological Survey]] | url=http://pubs.usgs.gov/of/2003/of03-337/global.html | accessdate=14 February 2005}} * [http://www.pol.ac.uk/psmsl/palaeoshoreline_webpage/HTML/HOME.htm Changes in the Earth's shorelines during the past 20 kyr caused by the deglaciation of the Late Pleistocene ice sheets], from the [[Permanent Service for Mean Sea Level]] * [http://indigenouspeoplesissues.com/index.php?option=com_content&view=article&id=385:indigenous-australian-aboriginal-perspectives-on-climate-change-cape-york-australia&catid=68:videos-and-movies&Itemid=96 Indigenous Aboriginal Australian Perspective on Sea Level Changes: Video] * [http://www.pol.ac.uk/psmsl/palaeoshoreline_webpage/HTML/Science.htm Includes picture of sea level for past 20 kyr based on barbados coral record] * [http://www.radix.net/~bobg/faqs/sea.level.faq.html Sea level rise FAQ] (1997) * [http://www.gloss-sealevel.org/ The Global Sea Level Observing System (GLOSS)] * [http://www.bodc.ac.uk/data/information_and_inventories/gloss_handbook/ The GLOSS Station Handbook] * {{cite web | title=Sea Level Rise Reports | publisher=[[United States Environmental Protection Agency]] |url=http://www.epa.gov/globalwarming/sealevelrise |archiveurl=http://web.archive.org/web/20090420064312/http://epa.gov/climatechange/effects/coastal/slrreports.html |archivedate=2009-04-20 }} * [http://www.thesinkingoftuvalu.com/ The Sinking of Tuvalu] * [http://www.interactive-earth.com/visualizations/sea_level_fluctuation.htm Tides and Sea Level Rise Model] ;Maps that show a rise in sea levels: * [http://www.csc.noaa.gov/slr Sea Level Rise and Coastal Flooding Impacts Viewer] Displays potential future sea levels, provides simulations of sea level rise at local landmarks, communicates the spatial uncertainty of mapped sea levels, models potential marsh migration due to sea level rise, overlays social and economic data onto potential sea level rise, and examines how tidal flooding will become more frequent with sea level rise [[NOAA Coastal Services Center]]. * [http://flood.firetree.net/ Sea Level Rise of up to 14m – meltdown of Greenlandic ice shield] * [http://www.elstel.com/SeaLevelRise.html#Maps World Maps for a sea level rise in 60m – meltdown of the antarctic ice shield] * [http://archive.cyark.org/hazard-map Hazard map showing variable sea level rise and earthquake impacts], developed by [[CyArk]] to demonstrate potential impact of climate change (and earthquakes) on [[World Heritage Sites]] * [http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml Sea Levels Online: National Ocean Service (CO-OPS)], displays local sea level rise and sea level trends via a map interface * [http://plan.risingsea.net/ Sea Level Rise Planning Maps] County and state scale maps showing which lands below 5 meters are likely and unlikely to be protected from a rising sea, according to study funded by the United States [[Environmental Protection Agency]]. * [http://ice.tsu.ru/index.php?option=com_content&task=view&id=588&Itemid=138 Sea level rise - How much and how fast will sea level rise over the coming centuries? Past.] * [http://ice.tsu.ru/index.php?option=com_content&task=view&id=587&Itemid=138 Sea level rise - How much and how fast will sea level rise over the coming centuries? Present] *[http://ocean.nationalgeographic.com/ocean/photos/sea-level-rise/ National Geographic Photo Gallery: Sea Level Rise] {{physical oceanography|expanded=other}} {{Global warming}} {{DEFAULTSORT:Current Sea Level Rise}} [[Category:Oceanography]] [[Category:Physical oceanography]] [[Category:Effects of global warming|Sea Level]] [[ja:海面上昇]] '