Sea level rise is the rise in global sea level as a result of the increase in water volume in the world's oceans. Sea level rise is usually associated with global climate change by thermal expansion of water in the oceans and by melting glaciers and glaciers on land. The melting of the floating ice and iceberg in the sea will raise the sea level to about 4 cm (1.6 inches).
Sea level rise in a particular location may be more or less than the global average. Local factors may include tectonic effects, soil degradation, tides, currents, storms, etc. Sea level rise is expected to continue for centuries. Due to the long response time for parts of the climate system, it has been estimated that we are already committed to rising sea levels within the next 2,000 years of approximately 2.3 meters (7.5 × ft) for every degree Celsius temperature rise. International Panel on Climate Change (IPCC) Summary for Policy Makers, AR5, 2014, predicts that global sea level rise will continue during the 21st century, most likely at a faster rate than observed from 1971 to 2010. Projected rates and quantities vary. The January 2017 NOAA report shows a range of GMSL increases of 0.3 - 2.5 m possibilities during the 21st century.
Broad coastal flooding would be expected if some degree of warming continued for thousands of years. For example, continuous global warming of more than 2 ° C (relative to pre-industrial levels) could lead to an increase in sea level of about 1 to 4 m due to thermal expansion of seawater and melting of small glaciers and ice.
Rising sea levels can greatly affect human populations in coastal and island areas and the natural environment such as marine ecosystems.
Video Sea level rise
Mekanisme
Two major mechanisms contribute to the observed sea level rise: (1) heat expansion: due to increased oceanic heat content (seawater expands as it warms); and (2) melting of soil ice shops such as ice sheets and glaciers. Based on figures between 1993-2008, two-thirds (68%) of recent sea level rise was caused by melting ice, and about one-third came from thermal expansion.
In the time span of centuries to millennia, melting of ice sheets can result in higher sea level rise. The partial deglaciation of the Greenland ice sheet, and perhaps the West Antarctic ice sheet, may contribute 4 to 6 m (13 to 20 feet) or more in sea level rise.
Maps Sea level rise
Previous changes at sea level
Various factors affect the volume or mass of the oceans, which causes long-term changes in the eustatic sea level. The two main effects are temperature (because water density depends on temperature), and water mass confined in land and sea as fresh water in rivers, lakes, glaciers and polar ice. Over the longer geological span, changes in the shape of the ocean basin and the distribution of land and sea affect the sea surface. Since the Last Glacial Maximum of about 20,000 years ago, sea level has increased by more than 125 m, with levels varying from one tenth of mm/y to 10 mm/yr, as a result of the melting of the main ice sheet.
During deglaciation between about 19,000 and 8,000 calendar years ago, sea levels rose at a very high rate as a result of the rapid melting of the British-Irish Seas, Fennoscandian, Laurentide, Barents-Kara, Patagonia, Innuitian ice sheets and Antarctic sections. ice sheet. At the beginning of the deglaciation of about 19,000 calendar years ago, a 500-year-long glacial-eustatic event may have contributed as much as 10 m to sea level with an average of about 20 mm/year. For the remainder of the early Holocene, sea level rise varied from a low of about 6.0-9.9 mm/year to as high as 30-60 mm/year for short periods of accelerated sea level rise.
Strong geological evidence, based largely on the analysis of deep coral reefs, exists for only three major periods of accelerated sea level rise, called freshwater pulses , during the last deglaciation. They are the Meltwater 1A pulses between about 14,600 and 14,300 calendar years ago; Meltwater pulse 1B between about 11,400 and 11,100 calendar years ago; and the Meltwater 1C pulse between 8,200 and 7,600 calendar years ago. Meltwater pulse 1A is 13.5 m rise for about 290 years centered on 14,200 calendar years ago and Meltwater 1B pulse was 7.5 m rise for about 160 years centered on 11,000 calendar year last year. In contrast, the period between 14,300 and 11,100 calendar years ago, which includes the Dryas Muda interval, is a reduced sea-surface interval of about 6.0-9.9 mm/yr. The Meltwater 1C pulse is centered on 8,000 calendar years and results in a 6.5 m increase in less than 140 years. Soaring sea level elevations during marine melting events clearly have implications for major ice loss events associated with ice sheets collapse. Major sources may have melted from the Antarctic ice sheet. Another study shows the northern hemisphere's source for melting water in the Laurentide ice sheet.
Recently, it has been widely accepted that the final Holocene, 3,000 years ago to present, sea level was almost stable before the acceleration of the rate of increase that varied between 1850 and 1900 AD. The final level of Holocene sea level rise has been estimated using evidence from archaeological sites and the final sediment of the Holocene, combined with tidal gauges and satellite records and geophysical modeling. For example, this study included the study of Roman wells in Caesarea and Rome piscinae in Italy. This method in combination suggests eustatic components averaging 0.07 mm/yr over the last 2000 years.
Since 1880, the oceans began to rise rapidly, up a total of 210 mm (8.3 inches) by 2009 causing widespread erosion worldwide and cost billions.
The sea surface rose 6cm during the 19th and 19th centuries in the 20th century. The evidence for this includes the longest geological observations, instrument records and the observed 20th century sea level rise. For example, geological observations show that over the last 2,000 years, sea level changes are small, with an average rate of only 0.0-0.2 mm per year. This is proportional to an average of 1.7 Â ± 0.5 mm per year for the 20th century. Baart et al. (2012) suggests that it is important to take into account the effect of a lunar node cycle of 18.6 years before the acceleration of sea level rise should be concluded. Based on the tide gauge data, the global average sea level rise rate during the 20th century was in the range of 0.8 to 3.3 mm/yr, with an average of 1.8 mm/year.
Current condition of sea level change
This NASA chart represents the satellite's bi-monthly data on the deep sea level with adjusted seasonal variations.
Projection
20th century
Hansen et al. 1981, published a study on climate impacts raising atmospheric carbon dioxide, and predicts that anthropogenic carbon dioxide heating and its potential effects on climate in the 21st century could lead to a sea level rise of 5 to 6 m, from the melting of the West Antarctic ice sheet only.
21st century
The Fourth Assessment Report 2007 (IPCC 4) projects sea level at the end of the century using the Special Report on Emission Scenarios (SRES). SRES develops emission scenarios to project climate change impacts. Projections based on this scenario are not predictions, but reflect a reasonable estimate of future social and economic developments (eg, economic growth, population levels). Six SRES "marker" scenarios projected sea levels to rise by 18 to 59 centimeters (7.1 to 23.2 inches). Their projection for the period 2090-99, with an increase in relative level to sea level on average during the period 1980-99. This estimate does not cover all possible contributions of the ice sheet.
Hansen (2007), assumes the contribution of 1 cm ice sheets for the 2005-15 decade, with a potential ten-year doubling time for sea level rise, based on the response of nonlinear ice sheets, which will produce 5 m of this century.
The average decline in sea ice recorded from 1953 to 2006 was -7.8% Ã, Â ± 0.6%/decade, this is more than three times the average forecast trend size -2.5% Ã, Â ± 0 , 2%/decade. Even the 'worst case scenario' model does not predict that sea ice decreases adequately. The fastest rate of sea ice decreases from one of the models associated with the Intergovernmental Panel on Climate Change The Fourth Assessment Report is -5.4% Ã, Â ± 0.4%/decade.
Research from 2008 observed a rapid decline in ice mass balance from Greenland and Antarctica, and concluded that sea level rise in 2100 is likely to be at least twice larger than that presented by IPCC AR4, with an upper limit of about two meters..
The projections assessed by the US National Research Council (2010) show the possibility of sea level rise during the 21st century between 56 and 200 cm (22 and 79 inches). The NRC describes the IPCC projections as "conservative".
In 2011, Rignot and others project an increase of 32 cm (13 inches) by 2050. Their projections include increased contributions from the Antarctic and Greenland ice sheets. The use of two completely different approaches reinforces Rignot's projection.
In the Fifth Assessment Report (2013), 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 are consistent with the number of contributions from ocean expansion observations due to temperature rise ( (0.76 [0.39-1.13] mm per year), the Greenland ice sheet is melted (0.33 [0.25- (0.27 [0.16 to 0.38] mm per year), and changes in groundwater storage (0.38 [0.26 to 0.49] mm per year). The report also concludes that if emissions continue to follow the worst IPCC scenario, global average sea level could rise by almost 1 million by 2100 (0.52-0.98 m from the 1986-2005 baseline). If emissions follow the lowest emission scenario, the global mean sea level is projected to increase between 0.28-0.6 m by 2100 (compared to the base of 1986-2005).
IPCC projections are conservative, and may underestimate sea level rise in the future. Other estimates suggest that for the same period, global sea levels could rise from 0.2 to 2.0 m (0.7-6.6 ft), relative to the mean sea level in 1992.
The Third National Climate Assessment (NCA), released May 6, 2014, projects a sea level rise of 1 to 4 feet (30-120 cm) by 2100. Decision-makers who are particularly vulnerable to risk may want to use a wider range of scenarios than 8 inch to 6.6 feet (20-200 cm) by 2100.
A 2015 study by sea level experts concluded that based on MIS 5e data, sea level rise can be accelerated in the coming decades, with doubling time of 10, 20 or 40 years. Abstract studies explain:
- "We are of the opinion that the ice sheet in contact with the ocean is susceptible to non-linear disintegration in response to ocean warming, and we assume that ice shear mass loss can be estimated by multiplier time to sea level rise of at least some meters, doubling times 10, 20 or 40 years produce a sea-level rise of several meters in 50, 100 or 200. Paleoclimate data reveal that sub-surface ocean warming causes ice melt and ice release. "
- "Our climate model exposes strengthening feedback in the Southern Ocean that slows down Antarctic water formation and raises ocean temperatures near ice barrier lines, while cooling sea levels and increasing layers sea ​​ice and water column stability, cooling sea levels, in the North Atlantic and in the Southern Ocean, increasing the tropospheric horizontal temperature gradient, eddy kinetic energy and baroclinicity, which encourages stronger storms. "
However, Greg Holland of the National Center for Atmospheric Research, which studies James (Jim) Hansen's study, notes "There is no doubt that sea-level rise, within the IPCC, is a very conservative figure, so the truth lies somewhere between IPCC and Jim. "
A 2017 study scenario, assuming high fossil fuel use for combustion and strong economic growth during this century, sea level improvement projects of up to 1.32 meters (4.3 feet) on average - and extreme scenarios with as many as 1, 89 meters (6.2 meters) Ã, ft), by 2100. This could mean a rapid sea level rise of up to 19 millimeters per year by the end of this century. The study also concluded that the Paris climate deal emissions scenario, if met, would result in a 0.52 meter (1.7Ã,f) sea level rise by 2100.
The melting of Greenland ice sheets can contribute an additional 4 to 7.5 m for thousands of years. It is estimated that we are already committed to a sea level rise of about 2.3 meters for every degree of temperature rise in the next 2,000 years.
Warming outside the 2 Â ° C target will potentially cause a sea level rise that is dominated by ice loss from Antarctica. Continuing CO 2 emissions from fossil sources could lead to an increase of more than ten meters of sea level rise, over the next millennium and eventually eventually eliminate all Antarctic ice sheets, which cause about 58 meters of sea level rise.
After 2100
There is widespread consensus that large long-term sea level rise will continue for centuries to come even if temperatures stabilize. IPCC AR4 estimates that at least partial degradation of the Greenland ice sheet, and possibly the West Antarctic ice sheet, will occur with an increase in global average temperature of 1-4 Â ° C (relative to temperature during 1990-2000). This estimate is given about 50% chance of being right. The estimated time scale is centuries to thousands of years, and will contribute 4 to 6 meters (13 to 20 feet) or more to sea level during this period.
Rising sea levels will cause flooding and will have the ability to wipe out the entire city. In a study published by Nature, the entire state of Delaware can be completely destroyed by 2500.
Model
There is the possibility of rapid change of glaciers, ice sheets, and sea levels. The prediction of such changes is very uncertain because of inadequate scientific understanding. Modeling processes associated with rapid ice and glacier change may potentially increase future sea level rise projections.
Hansen (2007), concluded that the model of paleoclimate ice sheets generally excludes ice flow physics, the effect of reduced surface melting through slit and basal flow of lubricants, or realistic interactions with the oceans. The modeling calibrations projected for future sea level rise are generally carried out with future linear sea projection. Thus does not include the potential nonlinear collapse of the ice sheet.
Contribution
Every year about 8 mm of rainfall (liquid equivalent) falls on the ice sheet in Antarctica and Greenland, mostly as snow, which accumulates and over time forms glacial ice. Much of this precipitation begins when water vapor evaporates from the surface of the ocean. For the first approach, the same amount of water appears to return to the oceans in the iceberg and from the ice melting at the edges. Scientists have previously estimated a larger, incoming or outgoing ice, called mass balance, important because a non-zero balance causes a change in global sea level. High precision gravimetry from satellites determines that Greenland lost more than 200 billion tons of ice per year, in line with the estimated loss from land measurement. The rate of ice loss is accelerating, growing from 137 billion tonnes in 2002-2003.
- The total global mass of ice lost from Greenland, Antarctica and Earth glaciers and ice cover during 2003-2010 is about 4300 billion tons (1,000 cubic miles), adding about 12 mm (0.5 inches) to sea level global, enough ice to cover an area comparable to US depths of 50 cm (1.5 feet).
- The melting of small glaciers on the outskirts of Greenland and the Antarctic Peninsula will increase the sea level by about 0.5 meters. At extreme potential, according to the Third Assessment Report of the International Panel on Climate Change, the ice contained in the Greenland ice sheet entirely melts raises the sea level by 7.2 meters (24 feet). The ice contained in the Antarctic ice sheet entirely melts will produce 61.1 meters (200 feet) sea-level change, both reaching a sea level rise of 68.3 meters (224 feet).
It is estimated that fully melted Antarctica will contribute more than 60 meters of sea level rise, and Greenland will contribute more than 7 meters. Small glaciers and ice caps on the outskirts of Greenland and the Antarctic Peninsula may contribute about 0.5 meters. The last figure is much smaller than Antarctica or Greenland, but it can happen relatively quickly (in the coming century), whereas the full Greenland smelter will be slow (maybe 1,500 years to completely deglaciate at the fastest possible pace) and Antarctica even slower. However, this calculation does not take into account the possibility of accelerating melting when the melt water flows beneath and lubricates a larger ice sheet, which will begin to move faster toward the sea.
In 2002, Eric Rignot and RH Thomas found that the West Antarctic and Greenland ice sheets lost mass, while the East Antarctic ice sheet was nearly balanced (they could not determine the mass balance sign for the East Antarctic ice sheet). Kwok and Comiso ( J. Climate , v15, 487-501, 2002) also found that temperature and pressure anomalies around West Antarctica and on the other side of the Antarctic Peninsula are correlated with recent South Oscillation events.
In 2005 it was reported that during 1992-2003, East Antarctica thickened at an average rate of about 18 mm/y while West Antarctica showed an overall depletion of 9 mm/year. associated with increased rainfall. This gain is sufficient to slow the rise in sea level by 0.12 Ã, Â ± 0.02 mm/year.
Antarctic
Large volumes of ice on the Antarctic continent save about 70% of the world's freshwater. This ice sheet is constantly getting ice from snowfall and losing ice through the stream to the ocean.
Sheperd et al. 2012, found that different satellite methods for measuring ice mass and changes in good agreement and combining methods lead to more certainty with Antarctica East, West Antarctica and Antarctic Peninsula changing massively by 14 Ã, Â ± 43, -65 Ã, Â ± 26, and -20 Â ± 14 gigatons (Gt) per year. A similar systematic review study in 2018 estimated that ice loss across the continent averaged 43 gigatons per year during the 1992-2002 period, but has accelerated to an average of 220 gigatons per year for five years from 2012 to 2017.
East Antarctic ice sheet (EAIS)
East Antarctica is a cold region with a foundation above sea level and occupies most of the continent. This area is dominated by a small accumulation of snow that becomes ice and thus eventually leads to the glacial oceans. The mass balance of the East Antarctic Ice Layers as a whole during the 1980-2004 period is considered to be slightly positive (lowers sea level) or nearly balanced, with a large degree of uncertainty. However, an increase in ice flow has been suggested in some areas.
West Antarctic ice sheet (WAIS)
West Antarctica is currently experiencing glacial ice flow, which will increase global sea level over time. A review of scientific studies looking at data from 1992 to 2006 shows that a net loss of about 50 gigatons of ice per year is a reasonable estimate (about 0.14 mm of annual sea level rise), despite significant acceleration of outflow glaciers in Amundsen Sea Embayment could have more than doubled this figure for 2006.
Thomas et al. find evidence of accelerated contribution to sea level rise from West Antarctica. The data show that the Amundsen Sea sector of the West Antarctic Ice Sheet takes 250 cubic kilometers of ice each year, which is 60% more than deposition sedimentation in the catchment area. This alone is enough to raise the sea level at 0.24 mm/year. Furthermore, the dilution rate for glaciers studied in 2002-03 has increased beyond the measured values ​​in the early 1990s. The underlying rocks of the glacier are found hundreds of meters deeper than previously known, showing an escape route from further inland in the Byrd Subpolar Basin. So the West Antarctic ice sheet may be unstable as expected.
A 2009 study found that the rapid collapse of the West Antarctic Ice Sheet would raise sea levels by up to 3.3 meters (11 feet).
Glacier
Observational studies and modeling of mass loss from glaciers and ice caps have contributed to sea level rise of 0.2-0.4 mm/yr, on average during the 20th century. Results from Dyurgerov show a sharp increase in the contribution of mounts and sub-polar glaciers to sea level rise since 1996 (0.5 mm/yr) to 1998 (2 mm/yr) with an average of about 0.35 mm/year since 1960 Yang Interestingly also is Arendt et al., which estimates Alaska glacier contribution of 0.14 Â ± 0.04 mm/year between the mid-1950s and mid-1990s, rising to 0.27 mm/yr in the middle and late 1990s..
Greenland
In 2004 Rignot et al. estimated contribution of 0.04 Ã, Â ± 0.01 mm/year for sea level rise from South East Greenland. In the same year, Krabill et al. estimated net contribution from Greenland at least 0.13 mm/year in the 1990s. Joughin et al. has measured the doubling speed of Jakobshavn IsbrÃÆ'Â| between 1997 and 2003. It is the largest outlet glacier in Greenland; it drains 6.5% of the ice sheet, and is thought to be responsible for increasing sea level rise by about 0.06 millimeters per year, or about 4% of the 20th century sea level rise. In 2004, Rignot et al. estimates the contribution of 0.04 Â ± 0.01 mm/year for sea level rise from southeastern Greenland.
Rignot and Kanagaratnam produced comprehensive studies and glaciers and Greenland basin maps. They found broad glacial accelerations below 66 N in 1996 that spread to 70 N in 2005; and that the rate of ice loss in the decade increased from 90 to 200 cubic km/year; this corresponds to an additional 0.25-0.55 mm/yr increase in sea level.
In July 2005 it was reported that the Kangerlussuaq Glacier, on the east coast of Greenland, moved toward the sea three times faster than a decade earlier. Kangerdlugssuaq has a thickness of about 1,000 m, a width of 7.2 km (4.5 miles), and spends about 4% of ice from the Greenland ice sheet. The measurements of Kangerdlugssuaq in 1988 and 1996 show that it moved between 5 and 6 km/yr (3.1-3.7 miles/yr), whereas in 2005 the speed had increased to 14 km/yr (8.7 mi/yr).
According to the Arctic Climate Impact Assessment 2004, climate models projected that local warming in Greenland would exceed 3 ° C during this century. In addition, the ice sheets model projected that such warming would initiate a long-term melting of ice sheets, leading to the complete melting of the Greenland ice sheets for several millennia, resulting in a global sea level rise of approximately seven meters.
Subsidence and effective sea level rise
Many ports, urban conglomerates, and agricultural areas are built on the river deltas, where land degradation contributes to the greatly increased sea level rise effective . This is due to unsustainable ground water extraction (in some places also by oil and gas extraction), and by dikes and other flood management practices that prevent sediment accumulation from compensation for the delta's natural sedimentation. In many deltas, this produces a decline that ranges from a few millimeters per year to perhaps 25 cm per year in parts of Ciliwung delta (Jakarta). Total anthropogenic induced decline in the Rhine-Meuse-Scheldt (Netherlands) delta is estimated at 3-4 meters, over 3 meters in the urban areas of the Mississippi River Delta (New Orleans), and over nine meters in the Sacramento-San Joaquin River Delta.
Effects
The IPCC TAR WGII ​​report Impact, Vulnerability of Adaptation notes that current and future climate change will be expected to have a number of impacts, especially on coastal systems. Such impacts may include increased coastal erosion, higher storm surge flows, inhibition of primary production processes, wider coastal ponds, changes in surface water quality and groundwater characteristics, increased loss of property and coastal habitats, increased risk of flooding and potential loss of life. , loss of cultural resources and non-monetary values, impact on agriculture and aquaculture through degradation of soil and water quality, and loss of tourism, recreation, and transportation functions.
There are implications that many of these impacts will be detrimental - especially to three quarters of the world's poor dependent on agricultural systems. However, the report notes that because of the enormous variety of coastal environments; regional and local differences in projected sea level and relative climate change; and differences in adaptive resilience and capacity of ecosystems, sectors, and countries, the impact will vary greatly in space and time.
The 2007 IPCC report estimates that accelerated Himalayan ice melt and rising sea levels will increase the severity of floods in the short term during the wet season and greatly increase the impact of tidal waves during the hurricane season. A sea level rise of just 400 mm in the Bay of Bengal will put 11 percent of the coastal plains of Bangladesh underwater, creating 7-10 million climate refugees.
Sea level rise can also replace many coastal populations: for example, it is estimated that a sea level rise of just 200 mm can make 740,000 people in Nigeria homeless.
Future sea level rise, such as recent increases, is not expected to be uniform globally. Some regions show sea level rise substantially more than the global average (in many cases more than twice the average), and other sea level levels fall. However, the model does not agree with sea level change patterns.
Island country
The IPCC assessment shows that the delta and small island states are highly vulnerable to sea level rise caused by thermal expansion and rising seawater. Sea level changes have not been conclusively proven to directly result in environmental, humanitarian or economic losses to small island states, but IPCC and other agencies have found this serious risk scenario in the coming decades.
Maldives, Tuvalu, and other lowland countries are among the areas at the highest risk level. The UN environmental panel has warned that, at current levels, sea levels will be high enough to make the Maldives uninhabitable by 2100.
Many media reports focusing on island nations in the Pacific, especially the Tuvalu Polynesian archipelago, which, according to more severe flood events in recent years, are considered "drowning" due to rising sea levels. A scientific review in 2000 reported that based on the University of Hawaii's measurement data, Tuvalu had a non-negligible increase in sea level of 0.07 mm per year over the past two decades, and that the El NiÃÆ'Â Â o Southern Oscillation (ENSO) had been a factor which is larger in higher Tuvalu tides in recent years. However, subsequent research by John Hunter of the University of Tasmania, adapted to the effects of ENSO and the movement of measuring instruments (which are thought to be sinking). Hunter concludes that Tuvalu has experienced a sea level rise of about 1.2 mm per year. More recent floods in Tuvalu may also be caused by erosion of soil during and after the 1997 cyclone action of Gavin, Hina, and Keli.
A study conducted in Jaluit Atoll, Marshall Islands showed that significant geomorphological events such as storms (ie Typhoon Ophelia in 1958) tended to have a greater impact on coral islands than the effect of a smaller scale of sea level rise. These effects include direct erosion and subsequent regeneration processes that can vary from decade to century, resulting in even larger ground areas than pre-storm values. With the expected increase in the frequency and intensity of storms, they can become more significant in determining the shape and size of the island than sea level rise.
By 2016 it was reported that five of the Solomon Islands had disappeared due to the combined effect of stronger sea-level rise and trade winds that pushed water into the Western Pacific.
In addition to the flood-induced problems, such as land salination, the island declares itself to be dispersed over time, as the islands become uninhabitable or completely submerged by the sea. Once this happens, all rights in the surrounding area (sea) are removed. This area can be very large as an extension of up to a radius of 224 nautical miles (414 km) across the island nation. Any resources, such as fossil fuels, minerals and metals, in this area can be freely excavated by anyone and sold without paying any commissions to an archipelagic country (now dissolved).
Options that have been proposed to help island countries to adapt to rising sea levels include leaving the islands, building embankments, and building upwards.
City
A study in the April 2007 issue of Environment and Urbanization reports that 634 million people live in coastal areas within 30 feet (9.1 m) of sea level. The study also reports that about two-thirds of the cities in the world with more than five million people are in this low-lying coastal region. Future sea level rise can cause great difficulties for coastal communities in the following centuries: for example, many large cities such as Venice, London, New Orleans and New York City are in need of storm defenses, and will require more if the surface sea ​​rise; they also face problems such as decline. However, modest sea level rise is likely to be balanced when cities adapt to building sea walls or through relocation.
Re-insurance company Re Re estimates economic losses to southeast Florida by 2030, from $ 33 billion from climate-related damage. Miami has been listed as "the world's number one most vulnerable city" in terms of potential property damage due to flooding and storm-related sea-level rise.
Habitat
Coastal and polar habitats face drastic changes as a consequence of rising sea levels. The loss of ice in the Arctic can force local species to migrate to find new homes. If seawater continues near land, problems associated with contaminated soil and flooded wetlands may occur. Also, fish, birds, and coastal plants may lose some of their habitat. In 2016 it was reported that Bramble Cay melomys, living on the island of Great Barrier Reef, may have become extinct due to rising sea levels.
Events extreme sea level rise
Downturn of Atlantic reverses circulating circulation (AMOC), has been associated with extreme regional sea level rise (1-in-850 year event). Between 2009-2010, sea level north of New York City increased 128 mm in two years. This jump is unprecedented in tidal meter records, which have been collecting data for several centuries.
Sea level measurement
Satellites
Since the launch of TOPEX/Poseidon 1992, altimetric satellites have recorded changes at sea level. Current sea level rise from altimetry satellites has been estimated in the range of 2.9-3.4 Â ± 0.4-0.6 mm per year for 1993-2010. It exceeds the tide gauge. It is unclear whether this is an accelerated increase over the last few decades, variability due to the rarely tidal meter sampling, the apparent difference between satellites and tidal gauges, or problems with satellite calibration. By 2015, a small calibration error from the first altimetry satellite - Topex/Poseidon - has been identified. That has led to a slight overestimation of the sea level from 1992 to 2005, which masked the ongoing acceleration of sea level rise.
Tide gauge
Amsterdam
The longest sea level measurement, the NAP or Amsterdam Ordnance Datum established in 1675, was recorded in Amsterdam, The Netherlands. About 25 percent of the Netherlands lies beneath the surface of the sea, while more than 50 percent of the country's territory will be flooded with temporary floods if it does not have a large embankment system, see Flood control in the Netherlands.
Australia
In Australia, data collected by the Commonwealth Scientific and Industrial Research Organization (CSIRO) shows current global sea level trends up to 3.2 mm/yr, twice the rate of total increase of about 210 mm measured from 1880 to 2009, which reflecting the average annual rise over a 129-year period of about 1.6 mm/year.
The Australian record collection has a long time horizon, including measurements by an amateur meteorologist who began in 1837 and measurements taken from a sea level benchmark of a small cliff on the Isle of the Dead near the Port Arthur inmate settlement on 1 July 1841. note, when compared with data recorded by modern tide gauges, reinforces the final comparison of the historic sea level rise of about 1.6 mm/yr, with sharp acceleration in recent decades.
Continuing Australia's extensive ocean level data collection (CSIRO) is summarized in average sea surface trends findings of 3.2 mm/year. In 2003, the National Tidal Center of the Bureau of Meteorology manages 32 pairs of gauges covering the entire coastline of Australia, with several measurements available starting in 1880.
United States
Tide gauges in the United States reveal considerable variations as some of the mainland areas are rising and some are sinking. For example, over the past 100 years, the rate of sea level rise varies from an increase of about 0.36 inches (9.1 mm) per year along the Louisiana Coast (due to sinking of land), down to several inches per decade in Alaska (due to post- -llacial). The rate of sea level rise increased during the period 1993-2003 compared to the long-term average (1961-2003), although it is not clear whether the faster rate reflects short-term variations or increases in long-term trends.
One study showed no acceleration of sea level rise on US tide gauges during the 20th century. However, other studies have found that the rate of increase for the US Atlantic coast during the 20th century is much higher than during the previous two thousand years.
Adaptation
In 2008, the Dutch Delta Commission (Deltacommissie), suggested in the report that the Netherlands will need a new massive development program to strengthen the country's water defenses against the anticipated effects of global warming for the next 190 years.. The Dutch plan includes drawing up the worst plans for evacuation. The plan includes more than EUR100 billion (US $ 144 billion), in new spending through 2100 to take steps, such as expanding beach hills and strengthening sea and river dikes. The commission said the country should plan a rise in the North Sea to 1.3 meters (4Ã, ft 3Ã, in) by 2100, rather than the previous projection of 0.80 meters (2Ã7 inches), and plans for 2-4 meters (6.5 -13 ft) up 2200.
The New York City Panel on Climate Change (NPCC), is an effort to prepare the New York City region for climate change.
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