A scaling approach to project regional sea level rise and its uncertainties

Abstract. Climate change causes global mean sea level to rise due to thermal expansion of seawater and loss of land ice from mountain glaciers, ice caps and ice sheets. Locally, sea level can strongly deviate from the global mean rise due to changes in wind and ocean currents. In addition, gravitational adjustments redistribute seawater away from shrinking ice masses. However, the land ice contribution to sea level rise (SLR) remains very challenging to model, and comprehensive regional sea level projections, which include appropriate gravitational adjustments, are still a nascent field (Katsman et al., 2011; Slangen et al., 2011). Here, we present an alternative approach to derive regional sea level changes for a range of emission and land ice melt scenarios, combining probabilistic forecasts of a simple climate model (MAGICC6) with the new CMIP5 general circulation models. The contribution from ice sheets varies considerably depending on the assumptions for the ice sheet projections, and thus represents sizeable uncertainties for future sea level rise. However, several consistent and robust patterns emerge from our analysis: at low latitudes, especially in the Indian Ocean and Western Pacific, sea level will likely rise more than the global mean (mostly by 10–20%). Around the northeastern Atlantic and the northeastern Pacific coasts, sea level will rise less than the global average or, in some rare cases, even fall. In the northwestern Atlantic, along the American coast, a strong dynamic sea level rise is counteracted by gravitational depression due to Greenland ice melt; whether sea level will be above- or below-average will depend on the relative contribution of these two factors. Our regional sea level projections and the diagnosed uncertainties provide an improved basis for coastal impact analysis and infrastructure planning for adaptation to climate change.

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Wind Effects on Past and Future Regional Sea Level Trends in the Southern Indo-Pacific*

Journal of Climate ◽

10.1175/2010jcli3519.1 ◽

2010 ◽

Vol 23 (16) ◽

pp. 4429-4437 ◽

Cited By ~ 140

Author(s):

Axel Timmermann ◽

Shayne McGregor ◽

Fei-Fei Jin

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

General Circulation ◽

General Circulation Models ◽

French Polynesia ◽

Near Surface ◽

Mean Sea Level ◽

Regional Sea Level ◽

Global Mean Sea Level ◽

Global Mean

Abstract Global sea level rise due to the thermal expansion of the warming oceans and freshwater input from melting glaciers and ice sheets is threatening to inundate low-lying islands and coastlines worldwide. At present the global mean sea level rises at 3.1 ± 0.7 mm yr−1 with an accelerating tendency. However, the magnitude of recent decadal sea level trends varies greatly spatially, attaining values of up to 10 mm yr−1 in some areas of the western tropical Pacific. Identifying the causes of recent regional sea level trends and understanding the patterns of future projected sea level change is of crucial importance. Using a wind-forced simplified dynamical ocean model, the study shows that the regional features of recent decadal and multidecadal sea level trends in the tropical Indo-Pacific can be attributed to changes in the prevailing wind regimes. Furthermore, it is demonstrated that within an ensemble of 10 state-of-the-art coupled general circulation models, forced by increasing atmospheric CO2 concentrations over the next century, wind-induced redistributions of upper-ocean water play a key role in establishing the spatial characteristics of projected regional sea level rise. Wind-related changes in near-surface mass and heat convergence near the Solomon Islands, Tuvalu, Kiribati, the Cook Islands, and French Polynesia oppose—but cannot cancel—the regional signal of global mean sea level rise.

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An Assessment of Global Macroeconomic Impacts Caused by Sea Level Rise Using the Framework of Shared Socioeconomic Pathways and Representative Concentration Pathways

Sustainability ◽

10.3390/su12093737 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3737

Author(s):

Osamu Nishiura ◽

Makoto Tamura ◽

Shinichiro Fujimori ◽

Kiyoshi Takahashi ◽

Junya Takakura ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Low Income ◽

Temperature Increase ◽

General Circulation ◽

Economic Losses ◽

Global Mean Temperature ◽

Mean Temperature ◽

Global Mean

Coastal areas provide important services and functions for social and economic activities. Damage due to sea level rise (SLR) is one of the serious problems anticipated and caused by climate change. In this study, we assess the global economic impact of inundation due to SLR by using a computable general equilibrium (CGE) model that incorporates detailed coastal damage information. The scenario analysis considers multiple general circulation models, socioeconomic assumptions, and stringency of climate change mitigation measures. We found that the global household consumption loss proportion will be 0.045%, with a range of 0.027−0.066%, in 2100. Socioeconomic assumptions cause a difference in the loss proportion of up to 0.035% without greenhouse gas (GHG) emissions mitigation, the so-called baseline scenarios. The range of the loss proportion among GHG emission scenarios is smaller than the differences among the socioeconomic assumptions. We also observed large regional variations and, in particular, the consumption losses in low-income countries are, relatively speaking, larger than those in high-income countries. These results indicate that, even if we succeed in stabilizing the global mean temperature increase below 2 °C, economic losses caused by SLR will inevitably happen to some extent, which may imply that keeping the global mean temperature increase below 1.5 °C would be worthwhile to consider.

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Change in mass balance of polar ice sheets and sea level from high-resolution GCM simulations of greenhouse warming

Annals of Glaciology ◽

10.3189/172756400781820741 ◽

2000 ◽

Vol 30 ◽

pp. 197-203 ◽

Cited By ~ 26

Author(s):

Martin Wild ◽

Atsumu Ohmura

Keyword(s):

Mass Balance ◽

Sea Level Rise ◽

Sea Level ◽

General Circulation ◽

Ice Sheets ◽

General Circulation Models ◽

Dominant Factor ◽

Greenhouse Warming ◽

Sea Level Changes ◽

And Sea Level

AbstractFor projecting future sea level, the mass-balance changes on Greenland and Antarctica are considered to be crucial. Promising tools for such estimates are general circulation models (GCM). Until recently, a major impediment was their coarse grid resolution (3°-6°) causing substantial uncertainties in the mass-balance calculations of the poorly resolved ice sheets. The present study is based on a new climate-change experiment of the highest resolution currently feasible (1.1 °) performed with the ECHAM4 T106 GCM, thereby increasing confidence in the projected mass-balance and sea-level changes. This new experiment, with doubled CO2 concentration, suggests that the mass gain in Antarctica due to increased accumulation exceeds the melt-induced mass loss in Greenland by a factor of three. The resulting mass-balance change on both ice sheets is equivalent to a net sea-level decrease of 0.6 mm a"1 under doubled CO2 conditions. This may compensate for a significant portion of the melt-induced sea-level rise from the smaller glaciers and ice caps, thus leaving thermal expansion as the dominant factor for sea-level rise over the next decades. This compensating effect, however, no longer applies should atmospheric CO2 concentration reach levels well above "doubled the present value". On the contrary, under these conditions, the greenhouse warming would become large enough to induce substantial melting also on the Antarctic ice sheet, thereby significantly accelerating global sea-level rise.

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Quantifying ambiguity in sea-level projections

10.5194/egusphere-egu21-2779 ◽

2021 ◽

Author(s):

Goneri Le Cozannet ◽

Jeremy Rohmer ◽

Jean-Charles Manceau ◽

Gael Durand ◽

Catherine Ritz ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Probability Model ◽

Ice Sheets ◽

Sea Level Changes ◽

Probabilistic Measure ◽

Mitigation And Adaptation ◽

Coastal Impacts ◽

Regional Sea Level

<p>Coastal impacts of climate change and the related mitigation and adaptation needs requires assessments of future sea-level changes. Following a common practice in coastal engineering, probabilistic sea-level projections have been proposed for at least 20 years. This requires a probability model to represent the uncertainties of future sea-level rise, which is not achievable because potential ice sheets mass losses remain poorly understood given the knowledge available today. Here, we apply the principles of extra-probabilistic theories of uncertainties to generate global and regional sea-level projections based on uncertain components. This approach assigns an imprecision to a probabilistic measure, in order to quantify lack of knowledge pertaining to probabilistic projections. This can serve to understand, analyze and communicate uncertainties due to the coexistence of different processes contributing to future sea-level rise, including ice-sheets. We show that the knowledge gained since the 5th Assessment report of the IPCC allows better quantification of how global and regional sea-level rise uncertainties can be reduced with lower greenhouse gas emissions. Furthermore, Europe and Northern America are among those profiting most from a policy limiting climate change to RCP 2.6 versus RCP 4.5 in terms of reducing uncertainties of sea-level rise.</p>

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Improved sea level record over the satellite altimetry era (1993–2010) from the Climate Change Initiative project

Ocean Science ◽

10.5194/os-11-67-2015 ◽

2015 ◽

Vol 11 (1) ◽

pp. 67-82 ◽

Cited By ~ 124

Author(s):

M. Ablain ◽

A. Cazenave ◽

G. Larnicol ◽

M. Balmaseda ◽

P. Cipollini ◽

...

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Satellite Altimetry ◽

Climate Model ◽

Atmospheric Correction ◽

European Space Agency ◽

Processing System ◽

Change Initiative ◽

Global Mean

Abstract. Sea level is one of the 50 Essential Climate Variables (ECVs) listed by the Global Climate Observing System (GCOS) in climate change monitoring. In the past two decades, sea level has been routinely measured from space using satellite altimetry techniques. In order to address a number of important scientific questions such as "Is sea level rise accelerating?", "Can we close the sea level budget?", "What are the causes of the regional and interannual variability?", "Can we already detect the anthropogenic forcing signature and separate it from the internal/natural climate variability?", and "What are the coastal impacts of sea level rise?", the accuracy of altimetry-based sea level records at global and regional scales needs to be significantly improved. For example, the global mean and regional sea level trend uncertainty should become better than 0.3 and 0.5 mm year−1, respectively (currently 0.6 and 1–2 mm year−1). Similarly, interannual global mean sea level variations (currently uncertain to 2–3 mm) need to be monitored with better accuracy. In this paper, we present various data improvements achieved within the European Space Agency (ESA) Climate Change Initiative (ESA CCI) project on "Sea Level" during its first phase (2010–2013), using multi-mission satellite altimetry data over the 1993–2010 time span. In a first step, using a new processing system with dedicated algorithms and adapted data processing strategies, an improved set of sea level products has been produced. The main improvements include: reduction of orbit errors and wet/dry atmospheric correction errors, reduction of instrumental drifts and bias, intercalibration biases, intercalibration between missions and combination of the different sea level data sets, and an improvement of the reference mean sea surface. We also present preliminary independent validations of the SL_cci products, based on tide gauges comparison and a sea level budget closure approach, as well as comparisons with ocean reanalyses and climate model outputs.

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Earth's energy imbalance and implications

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-13421-2011 ◽

2011 ◽

Vol 11 (24) ◽

pp. 13421-13449 ◽

Cited By ~ 311

Author(s):

J. Hansen ◽

M. Sato ◽

P. Kharecha ◽

K. von Schuckmann

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Solar Minimum ◽

Climate Forcing ◽

Future Climate Change ◽

Ocean Heat Uptake ◽

Surface Temperature Change ◽

Energy Imbalance ◽

Ice Melt

Abstract. Improving observations of ocean heat content show that Earth is absorbing more energy from the Sun than it is radiating to space as heat, even during the recent solar minimum. The inferred planetary energy imbalance, 0.58 ± 0.15 W m−2 during the 6-yr period 2005–2010, confirms the dominant role of the human-made greenhouse effect in driving global climate change. Observed surface temperature change and ocean heat gain together constrain the net climate forcing and ocean mixing rates. We conclude that most climate models mix heat too efficiently into the deep ocean and as a result underestimate the negative forcing by human-made aerosols. Aerosol climate forcing today is inferred to be −1.6 ± 0.3 W m−2, implying substantial aerosol indirect climate forcing via cloud changes. Continued failure to quantify the specific origins of this large forcing is untenable, as knowledge of changing aerosol effects is needed to understand future climate change. We conclude that recent slowdown of ocean heat uptake was caused by a delayed rebound effect from Mount Pinatubo aerosols and a deep prolonged solar minimum. Observed sea level rise during the Argo float era is readily accounted for by ice melt and ocean thermal expansion, but the ascendency of ice melt leads us to anticipate acceleration of the rate of sea level rise this decade.

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The land-ice contribution to 21st century dynamic sea-level rise

Ocean Science Discussions ◽

10.5194/osd-11-123-2014 ◽

2014 ◽

Vol 11 (1) ◽

pp. 123-169 ◽

Cited By ~ 1

Author(s):

T. Howard ◽

J. Ridley ◽

A. K. Pardaens ◽

R. T. W. L. Hurkmans ◽

A. J. Payne ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

21St Century ◽

Sea Level Change ◽

Sea Level Changes ◽

Mean Sea Level ◽

Ice Melt ◽

Level Change ◽

Global Mean ◽

Dynamic Sea Level

Abstract. Climate change has the potential to locally influence mean sea level through a number of processes including (but not limited to) thermal expansion of the oceans and enhanced land ice melt. These lead to departures from the global mean sea level change, due to spatial variations in the change of water density and transport, which are termed dynamic sea level changes. In this study we present regional patterns of sea-level change projected by a global coupled atmosphere–ocean climate model forced by projected ice-melt fluxes from three sources: the Antarctic ice sheet, the Greenland ice sheet and small glaciers and ice caps. The largest ice melt flux we consider is equivalent to almost 0.7 m of global sea level rise over the 21st century. Since the ice melt is not constant, the evolution of the dynamic sea level changes is analysed. We find that the dynamic sea level change associated with the ice melt is small, with the largest changes, occurring in the North Atlantic, contributing of order 3 cm above the global mean rise. Furthermore, the dynamic sea level change associated with the ice melt is similar regardless of whether the simulated ice fluxes are applied to a simulation with fixed or changing atmospheric CO2.

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Qualitative Modeling of Ice Sheet Accumulation for Identification of Mass Balance Variation

Advances in Web Technologies and Engineering - Dynamic Knowledge Representation in Scientific Domains ◽

10.4018/978-1-5225-5261-1.ch005 ◽

2018 ◽

pp. 99-118

Author(s):

Kirill Khvorostovsky ◽

Pavel Lunev ◽

Victoria Shterkhun

Keyword(s):

Climate Change ◽

Mass Balance ◽

Sea Level Rise ◽

Sea Level ◽

Ice Sheets ◽

Physical Models ◽

Qualitative Model ◽

Qualitative Modeling ◽

Formation And Evolution ◽

Methods Of Measurement

Formation and evolution of ice sheets is one of the “hot” problems of modern geosciences, as it has direct implication on the issues of climate change and sea level rise. Different methods of measurement or computing the mass balance of modern ice sheets based on various physical models sometimes give conflicting results. To understand them, one should first reconcile the models they are based on. This, in turn, requires one to decipher the vision different researchers have on the generation and evolution of ice sheets. This vision is initially qualitative. Hence, a qualitative model is desired that would reconcile various, and sometimes conflicting, physical models. This chapter proposes this model.

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Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

Earth System Dynamics ◽

10.5194/esd-2-25-2011 ◽

2011 ◽

Vol 2 (1) ◽

pp. 25-35 ◽

Cited By ~ 33

Author(s):

J. Schewe ◽

A. Levermann ◽

M. Meinshausen

Keyword(s):

Global Warming ◽

Sea Level Rise ◽

Sea Level ◽

21St Century ◽

General Circulation ◽

Full Range ◽

General Circulation Models ◽

Surface Cooling ◽

Steric Sea Level ◽

Intermediate Depth

Abstract. We present climatic consequences of the Representative Concentration Pathways (RCPs) using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM) using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of future greenhouse gas (GHG) concentrations pathways currently discussed. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 1.3 m of steric sea level rise by 2250, and 2 m by 2500, under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m) is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

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The Inevitable One

10.1093/oso/9780197502556.003.0006 ◽

2021 ◽

pp. 228-248

Author(s):

Eelco J. Rohling

Keyword(s):

Thermal Expansion ◽

Global Warming ◽

Sea Level Rise ◽

Sea Level ◽

Ice Sheets ◽

Ocean Warming ◽

Global Mean Temperature ◽

To Come ◽

Global Mean ◽

And Sea Level

This chapter considers processes we cannot reverse, at least in the short term: it is already too late. These are processes related to slow responses or feedbacks in the climate system, including ocean warming and sea-level rise, and they will continue to drive change whatever we do. As explained in the chapter, ocean warming operates on timescales of centuries and resulting changes in Earth’s major ice sheets take many centuries to millennia. Sea-level rise is caused by thermal expansion due to ocean warming and by reduction in the volume of land-based ice, due to global warming. Because of the timescales involved, the oceans will keep warming for centuries, dragging global mean temperature along with them, and sea level will also rise for many centuries to come. The chapter reviews the impacts of these processes, whose inevitability means that humanity has no choice but to adapt to them.

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