We estimate the rise in global average sea level from satellite altimeter data for 1993–2009 and from coastal and island sea-level measurements from 1880 to 2009. For 1993–2009 and after correcting for glacial isostatic adjustment, the estimated rate of rise is 3.2 ± 0.4 mm year−1 from the satellite data and 2.8 ± 0.8 mm year−1 from the in situ data. The global average sea-level rise from 1880 to 2009 is about 210 mm. The linear trend from 1900 to 2009 is 1.7 ± 0.2 mm year−1 and since 1961 is 1.9 ± 0.4 mm year−1. There is considerable variability in the rate of rise during the twentieth century but there has been a statistically significant acceleration since 1880 and 1900 of 0.009 ± 0.003 mm year−2 and 0.009 ± 0.004 mm year−2, respectively. Since the start of the altimeter record in 1993, global average sea level rose at a rate near the upper end of the sea level projections of the Intergovernmental Panel on Climate Change’s Third and Fourth Assessment Reports. However, the reconstruction indicates there was little net change in sea level from 1990 to 1993, most likely as a result of the volcanic eruption of Mount Pinatubo in 1991.

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Sea-Level Rise from the Late 19th to the Early 21st Century

[1] Multi-century sea-level records and climate models indicate an acceleration of sea-level rise, but no 20th century acceleration has previously been detected. A reconstruction of global sea level using tide-gauge data from 1950 to 2000 indicates a larger rate of rise after 1993 and other periods of rapid sea-level rise but no significant acceleration over this period. Here, we extend the reconstruction of global mean sea level back to 1870 and find a sea-level rise from January 1870 to December 2004 of 195 mm, a 20th century rate of sea-level rise of 1.7 ± 0.3 mm yr−1 and a significant acceleration of sea-level rise of 0.013 ± 0.006 mm yr−2. This acceleration is an important confirmation of climate change simulations which show an acceleration not previously observed. If this acceleration remained constant then the 1990 to 2100 rise would range from 280 to 340 mm, consistent with projections in the IPCC TAR.

/pdf/a-20th-century-acceleration-in-global-sea-level-rise-51vgfva4tt.pdf

A 20th century acceleration in global sea-level rise

The oceans are warming. Over the period 1961 to 2003,
global ocean temperature has risen by 0.10°C from the
surface to a depth of 700 m. Consistent with the Third
Assessment Report (TAR), global ocean heat content (0–
3,000 m) has increased during the same period, equivalent
to absorbing energy at a rate of 0.21 ± 0.04 W m–2 globally
averaged over the Earth’s surface. Two-thirds of this energy
is absorbed between the surface and a depth of 700 m.
Global ocean heat content observations show considerable
interannual and inter-decadal variability superimposed on
the longer-term trend. Relative to 1961 to 2003, the period
1993 to 2003 has high rates of warming but since 2003
there has been some cooling.

Observations: Oceanic Climate Change and Sea Level

We propose a simple relationship linking global sea-level variations on time scales of decades to centuries to global mean temperature. This relationship is tested on synthetic data from a global climate model for the past millennium and the next century. When applied to observed data of sea level and temperature for 1880–2000, and taking into account known anthropogenic hydrologic contributions to sea level, the correlation is >0.99, explaining 98% of the variance. For future global temperature scenarios of the Intergovernmental Panel on Climate Change's Fourth Assessment Report, the relationship projects a sea-level rise ranging from 75 to 190 cm for the period 1990–2100.

/pdf/global-sea-level-linked-to-global-temperature-31y4aymzu4.pdf

Global sea level linked to global temperature

https://appliedecology.cals.ncsu.edu/absci/wp-content/uploads/Gilman-et-al2008.pdf

Threats to mangroves from climate change and adaptation options: A review

Holgate, S.J.; Matthews, A.; Woodworth, P.L.; Rickards, L.J.; Tamisiea, M.E.; Bradshaw, E.; Foden, P.R.; Gordon, K.M.; Jevrejeva, S., and Pugh, J., 2013. New data systems and products at the Permanent Service for Mean Sea Level. Sea-level rise remains one of the most pressing societal concerns relating to climate change. A significant proportion of the global population, including many of the world's large cities, are located close to the coast in potentially vulnerable regions such as river deltas. The Permanent Service for Mean Sea Level (PSMSL) continues to evolve and provide global coastal sea-level information and products that help to develop our understanding of sea-level and land motion processes. Its work aids a range of scientific research, not only in long-term change, but also in the measurement and understanding of higher frequency variability such as storm surges and tsunamis. The PSMSL has changed considerably over the past 10 years, and the aim of this paper is to update the commu...

https://bioone.org/journals/Journal-of-Coastal-Research/volume-29/issue-3/JCOASTRES-D-12-00175.1/New-Data-Systems-and-Products-at-the-Permanent-Service-for/10.2112/JCOASTRES-D-12-00175.1.pdf

New Data Systems and Products at the Permanent Service for Mean Sea Level

into 13 regions with near global coverage and using a Glacial Isostatic Adjustment (GIA) model to correct for land movements. We present evidence from altimeter data that the rate of sea level rise around the global coastline was significantly in excess of the global average over the period 1993–2002. We also show that the globally-averaged rate of coastal sea level rise for the decade centered on 1955 was significantly larger than any other decade during the past 55 years. In some models of sea level rise, enhanced coastal riseisapre-cursorofglobalaveragerise.Itremainstobe seen whether the models are correct and whether global-average rates in the future reflect the high rates of coastal rise observed during the 1990s. INDEX TERMS: 1635 Global Change: Oceans (4203); 1223 Geodesy and Gravity: Ocean/ Earth/atmosphere interactions (3339); 4215 Oceanography: General: Climate and interannual variability (3309); 4556 Oceanography: Physical: Sea level variations. Citation: Holgate, S. J., and P. L. Woodworth (2004), Evidence for enhanced coastal sea level rise during the 1990s, Geophys. Res. Lett., 31, L07305,

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004GL019626

Evidence for enhanced coastal sea level rise during the 1990s

We analyze the Permanent Service for Mean Sea Level (PSMSL) database of sea level time series using a method based on Monte Carlo Singular Spectrum Analysis (MC-SSA). We remove 2 - 30 year quasi-periodic oscillations and determine the nonlinear long-term trends for 12 large ocean regions. Our global sea level trend estimate of 2.4 +/- 1.0 mm/yr for the period from 1993 to 2000 is comparable with the 2.6 +/- 0.7 mm/yr sea level rise calculated from TOPEX/Poseidon altimeter measurements. However, we show that over the last 100 years the rate of 2.5 +/- 1.0 mm/yr occurred between 1920 and 1945, is likely to be as large as the 1990s, and resulted in a mean sea level rise of 48 mm. We evaluate errors in sea level using two independent approaches, the robust bi-weight mean and variance, and a novel "virtual station'' approach that utilizes geographic locations of stations. Results suggest that a region cannot be adequately represented by a simple mean curve with standard error, assuming all stations are independent, as multiyear cycles within regions are very significant. Additionally, much of the between-region mismatch errors are due to multiyear cycles in the global sea level that limit the ability of simple means to capture sea level accurately. We demonstrate that variability in sea level records over periods 2 - 30 years has increased during the past 50 years in most ocean basins.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2005JC003229

Nonlinear trends and multiyear cycles in sea level records

Nine long and nearly continuous sea level records were chosen from around the world to explore rates of change in sea level for 1904 - 2003. These records were found to capture the variability found in a larger number of stations over the last half century studied previously. Extending the sea level record back over the entire century suggests that the high variability in the rates of sea level change observed over the past 20 years were not particularly unusual. The rate of sea level change was found to be larger in the early part of last century (2.03 +/- 0.35 mm/yr 1904 - 1953), in comparison with the latter part ( 1.45 +/- 0.34 mm/yr 1954 - 2003). The highest decadal rate of rise occurred in the decade centred on 1980 (5.31 mm/yr) with the lowest rate of rise occurring in the decade centred on 1964 ( - 1.49 mm/yr). Over the entire century the mean rate of change was 1.74 +/- 0.16 mm/yr

/pdf/on-the-decadal-rates-of-sea-level-change-during-the-4peic9a16o.pdf

On the decadal rates of sea level change during the twentieth century

A modification in the rate of change of sea level (i.e. an ‘acceleration’ or ‘nonlinear trend’) is an important climate-related signal, which requires confirmation and explanation. In this study, the evidence for accelerations in regional and global average sea level on timescales of several decades and longer is reviewed by inter-comparison of the recent findings of different researchers and by inspection of original tide gauge records. Most sea-level data originate from Europe and North America, and both the sets display evidence for a positive acceleration, or ‘inflexion’, around 1920–1930 and a negative one around 1960. These inflexions are the main contributors to reported accelerations since the late 19th century, and to decelerations during the mid- to late 20th century. However, these characteristic features are not always found in records from other parts of the world. Although some aspects of the sea-level time series are consistent with changes in rates of globally averaged temperature changes, volcanic eruptions and natural climate variability, modelling undertaken so far has been unable to describe these features adequately. This emphasizes the need for a major enhancement of the sea-level data set, especially for those parts of the world without long tide gauge records, in order to obtain greater insight into the spatial dependence of accelerations. A number of complementary methods must be employed, of which salt marsh techniques offer the possibility of obtaining time series similar to those that would have been obtained from coastal tide gauges. Copyright © 2008 Royal Meteorological Society

Simon Holgate

Papers

New Data Systems and Products at the Permanent Service for Mean Sea Level

Evidence for enhanced coastal sea level rise during the 1990s

Nonlinear trends and multiyear cycles in sea level records

On the decadal rates of sea level change during the twentieth century

Evidence for the accelerations of sea level on multi-decade and century timescales.