Can the Dongzhaigang Mangrove in China Adapt to Sea Level Rise in the Future?

Abstract Considering climate change, coastal mangroves are facing serious threats from rising sea levels. However, whether the largest contiguous Dongzhaigang mangrove in China can adapt to future sea level rise, which is very critical for mangrove restoration and management, has been little known. Using the data of historical monitor since the 1950s, supplementary field research of mangrove wetland sediment rates measured, satellite remote sensing, digital elevation model, global climate models, and ArcGIS, we investigated the Dongzhaigang mangrove area changes, related causes, and the impacts of future sea level rise under greenhouse gas emission scenarios, as representative concentration pathways (RCPs) 2.6, 4.5, and 8.5. The study revealed that: (1) during 1956–1987, total mangrove area had decreased by ~ 50%, from ~ 3417 hm2 to ~ 1710 hm2. This was mainly because of the impacts of human activities, such as fish pond reclamation and the use of former mangrove land for economic tree planting. After the 1990s, the total mangrove area was maintained at ~ 1711 hm2, mainly because of the establishment of the nature reserve in 1986, along with protective and restorative measures; (2) under the intermediate and high RCP 4.5 and 8.5, sea level increases are likely to cause > 25% of the mangroves to disappear by 2100, whereas for the low RCP 2.6, only 17% of the mangroves are likely to be affected; and (3) taking measures such as reestablishing ponds as mangrove forests, plant restoration, and biological shore protection could improve the adaptation of mangroves to the impacts of rising sea levels.

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Conservation Choices in the Face of Sea-Level Rise: A Case Study on Marsh Migration from Phippsburg, Maine

Agricultural and Resource Economics Review ◽

10.1017/age.2017.24 ◽

2017 ◽

Vol 46 (2) ◽

pp. 388-419 ◽

Cited By ~ 1

Author(s):

Sahan T. M. Dissanayake ◽

Meagan K. Hennessey

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Land Conservation ◽

Simulation Data ◽

Sea Levels ◽

Decision Method ◽

The Face ◽

Rising Sea Levels ◽

Knapsack Algorithm

We analyze the benefits of incorporating climate change into land conservation decisions using wetland migration under rising sea-levels as a case study. We use a simple and inexpensive decision method, a knapsack algorithm implemented in Excel, with (1) simulation data to show that ignoring sea-level rise predictions lead to suboptimal outcomes, and (2) an application to land conservation in Phippsburg, Maine to show the real-world applicability. The simulation shows an 11-percent to almost 30-percent gain in increased benefits when accounting for sea-level rise. The results highlight that it is possible to, and important to, incorporate sea-level rise into conservation planning.

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Socioeconomic and environmental predictors of estuarine shoreline hard armoring

Scientific Reports ◽

10.1038/s41598-019-52504-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Nicole E. Peterson ◽

Craig E. Landry ◽

Clark R. Alexander ◽

Kevin Samples ◽

Brian P. Bledsoe

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Economic Consequences ◽

Coastal Hazards ◽

Environmental Predictors ◽

Sea Levels ◽

Shoreline Armoring ◽

Rising Sea Levels ◽

Estuarine Shoreline ◽

The Individual

Abstract Rising sea levels and growing coastal populations are intensifying interactions at the land-sea interface. To stabilize upland and protect human developments from coastal hazards, landowners commonly emplace hard armoring structures, such as bulkheads and revetments, along estuarine shorelines. The ecological and economic consequences of shoreline armoring have garnered significant attention; however, few studies have examined the extent of hard armoring or identified drivers of hard armoring patterns at the individual landowner level across large geographical areas. This study addresses this knowledge gap by using a fine-scale census of hard armoring along the entire Georgia U.S. estuarine coastline. We develop a parsimonious statistical model that accurately predicts the probability of armoring emplacement at the parcel level based on a set of environmental and socioeconomic variables. Several interacting influences contribute to patterns of shoreline armoring; in particular, shoreline slope and the presence of armoring on a neighboring parcel are strong predictors of armoring. The model also suggests that continued sea level rise and coastal population growth could trigger future increases in armoring, emphasizing the importance of considering dynamic patterns of armoring when evaluating the potential effects of sea level rise. For example, evolving distributions of armoring should be considered in predictions of future salt marsh migration. The modeling approach developed in this study is adaptable to assessing patterns of hard armoring in other regions. With improved understanding of hard armoring distributions, sea level rise response plans can be fully informed to design more efficient scenarios for both urban development and coastal ecosystems.

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Mapping the soft and ethical dimensions of sea level rise in southern Sweden

10.5194/egusphere-egu2020-21324 ◽

2020 ◽

Author(s):

Lisa Van Well ◽

Anette Björlin ◽

Per Danielsson ◽

Godefroid Godefroid Ndayikengurukiye ◽

Gunnel Göransson

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Coastal Areas ◽

Ecological Impacts ◽

Gis Mapping ◽

Ethical Values ◽

Southern Sweden ◽

Sea Levels ◽

Rising Sea Levels

Sea level rise poses profound challenges within current municipal and regional governance since it requires unusually long planning horizons, is surrounded by great uncertainties, and gives rise to novel ethical challenges. Adaptation to climate change is fundamentally an ethical issue because the aim of any proposed adaptation measure is to protect that which is valued in society. One of the most salient ethical issues discussed in the adaptation literature relates to the distribution of climate related risks, vulnerabilities and benefits across populations and over time. Raising sea-walls is typically associated with high costs and potentially negative ecological impacts as well as substantial equity concerns; managed retreat or realignment often causes problems related to property rights; and migration out of low-lying areas can involve the loss of sense and cultural identity and impact on receiving communities.How can the soft and ethical dimensions of rising mean sea levels be characterized and how can their consequences be mapped? To help municipalities to understand the values and ethics attached to measures to deal with long-term rising sea levels in southern Sweden, we are developing a methodology of soft or ethical values to complement to GIS-mapping of coastal vulnerability based on coastal characteristics and socio-economic factors.Rather than determining these values a priori, they are being discerned through workshops with relevant stakeholders and in interviews with citizens residing in and utilizing the coastal areas. The methodology attempts to determine the place-based of values within coastal communities with a focus on &#8220;whose&#8221; values, &#8220;what&#8221; values, and the long-term or short-term nature of values. It builds on an analytical framework developed to acquire information on the behavior, knowledge, perception and feelings of people living, working and enjoying the coastal areas. &#160;In turn this stakeholder-based information is used to co-create &#8220;story maps&#8221; as tools to communicate complicated vulnerability analyses, highlight the ethical dimensions of various adaptation measures, raise awareness and aid decisionmakers in taking uncomfortable decisions to &#8220;wicked&#8221; planning problems around the negative effects of sea level rise, coastal erosion and urban flooding.This paper presents the methodological development of the task as well as the results the study in four Swedish municipalities. The representation of the &#8220;soft&#8221; and ethical values provides an opportunity to help clarify these values to policymakers and increase resilience to rising sea levels.

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Rising Sea Levels Bring a Tidal Change to Tourism

Eos ◽

10.1029/2021eo157200 ◽

2021 ◽

Vol 102 ◽

Author(s):

Richard Sima

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Sea Levels ◽

Rising Sea Levels ◽

Tidal Change

A series of industry posters reimagines iconic locales in light of sea level rise and issues a call for action against climate change.

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Multi-Criteria Decision Analysis of Coastal Inundation at Regional scale

10.5194/egusphere-egu21-6963 ◽

2021 ◽

Author(s):

Vinay Shivamurthy ◽

Bharath Aithal

Keyword(s):

High Risk ◽

Decision Analysis ◽

Sea Level Rise ◽

Sea Level ◽

Natural Hazards ◽

Flood Risk ◽

Sea Levels ◽

Risk Levels ◽

Multi Criteria Decision Analysis ◽

Rising Sea Levels

Coastal flooding are natural processes that are both i) essential (providing nutrients to the coastal vegetation, habitats) and ii) hazardous (negatively impact human activities, livelihood, assets, livestock and so on). Climate changes have induced higher frequency of floods, rising sea levels, high amplitude tides and other climatic extremes at regional to global scales. The increasing intensity, duration of floods is proportionately increasing the risks associated with coastal human habitations. The regional risks are defined based on the physical, demographic, socio-economic vulnerability of the habitants. Sea level rise would further enhance the coastal inundations permanently breaching these productive, densely populated regions. This necessitates the need for spatially assessing the relative hazard, vulnerability and risks at regional scales to reduce/mitigate risks.Indian subcontinent supports the second largest global population, with numerous megacities, towns and villages along the coast and mainland. This study's main objective is to quantify the risk associated with inundations caused by rising sea levels, tidal surge at the regional level. As a case study, Sagar Island located in the verge of Sundarbans, south of West Bengal is considered. Flood risk assessment in the island has been carried out using Multi-Criteria Decision Analysis (MCDA) framework based on 23 spatial parameters.Results indicate, within a century (1922 &#8211; 2020), the island has lost most of its natural vegetation (mangroves - Sundarbans) (47% to 3%), with increasing cultivated (agriculture, horticulture) spaces (77.4 %) and built-up environs (8.2%). Sea level rise varies from 4.4 mm/year (South) to 5.25 mm/year (North) and in the last century has breached over 2824 hectares of mainland. The study's findings reveal 19.8% of horticulture and 33.3% of agriculture assets are highly exposed to natural hazards. 1.34% population are at relatively very high-risk levels, 17.81% at high-risk levels. The study's findings reveal the variable importance of socio-economic, demographic, topographic and proximity to public service, in defining the flood vulnerability and risk towards the habitants. The approach and findings of paves the way for planning authorities to prioritise risk mitigation strategies that are region-specific to reduce the impact of inundation due to natural hazardsKeywords: Sea level rise, Flood risk, MCDA, Vulnerability, flood hazard

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A regional atmospheric warming threshold for irreversible Greenland ice sheet mass loss

10.5194/egusphere-egu2020-19032 ◽

2020 ◽

Author(s):

Michiel van den Broeke ◽

Brice Noël ◽

Leo van Kampenhout ◽

Willem-Jan van de Berg

Keyword(s):

Mass Loss ◽

Mass Balance ◽

Sea Level Rise ◽

Sea Level ◽

Climate Models ◽

Climate Model ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Global Climate Models ◽

The Future

The mass balance of the Greenland ice sheet (GrIS, units Gt per year) equals the surface mass balance (SMB) minus solid ice discharge across the grounding line. As the latter is definite positive, an important threshold for irreversible GrIS mass loss occurs when long-term average SMB becomes negative. For this to happen, runoff (mainly meltwater, some rain) must exceed mass accumulation (mainly snowfall minus sublimation). Even for a single year, this threshold has not been passed since at least 1958, the first year with reliable estimates of SMB components, although recent years with warm summers (e.g. 2012 and 2019) came close. Simply extrapolating the recent (1991-present) negative SMB trend into the future suggests that the SMB = 0 threshold could be reached before ~2040, but such predictions are extremely uncertain given the very large interannual SMB variability, the relative brevity of the time series and the uncertainty in future warming. In this study we use a cascade of models, extensively evaluated with in-situ and remotely sensed (GRACE) SMB observations, to better constrain the future regional warming threshold for the 5-year average GrIS SMB to become negative. To this end, a 1950-2100 climate change run with the global model CESM2 (app. 100 km resolution) was dynamically downscaled using the regional climate model RACMO2 (app. 11 km), which in turn was statistically downscaled to 1 km resolution. The result is a threshold regional Greenland warming of close to 4 degrees. We then use a range of CMIP5 and CMIP6 global climate models to translate the regional value into a global warming threshold for various warming scenarios, including its timing this century. We find substantial differences, ranging from stabilization before the threshold is reached in the RCP/SSP2.6 scenarios with a limited but still significant sea-level rise contribution (< 5 cm by 2100) to an imminent crossing of the warming threshold for the RCP/SSP8.5 scenarios with substantial and ever-growing contributions to sea level rise (> 10 cm by 2100). These results stress the need for strong mitigation to avoid irreversible GrIS mass loss. We finish by discussing the caveats and uncertainties of our approach.

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Compound Hydrometeorological Extremes: Drivers, Mechanisms and Methods

Frontiers in Earth Science ◽

10.3389/feart.2021.673495 ◽

2021 ◽

Vol 9 ◽

Author(s):

Wei Zhang ◽

Ming Luo ◽

Si Gao ◽

Weilin Chen ◽

Vittal Hari ◽

...

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Statistical Modeling ◽

Storm Surge ◽

Climate Models ◽

Heat Waves ◽

Numerical Models ◽

Global Climate ◽

The State ◽

Global Climate Models

Compound extremes pose immense challenges and hazards to communities, and this is particularly true for compound hydrometeorological extremes associated with deadly floods, surges, droughts, and heat waves. To mitigate and better adapt to compound hydrometeorological extremes, we need to better understand the state of knowledge of such extremes. Here we review the current advances in understanding compound hydrometeorological extremes: compound heat wave and drought (hot-dry), compound heat stress and extreme precipitation (hot-wet), cold-wet, cold-dry and compound flooding. We focus on the drivers of these extremes and methods used to investigate and quantify their associated risk. Overall, hot-dry compound extremes are tied to subtropical highs, blocking highs, atmospheric stagnation events, and planetary wave patterns, which are modulated by atmosphere-land feedbacks. Compared with hot-dry compound extremes, hot-wet events are less examined in the literature with most works focusing on case studies. The cold-wet compound events are commonly associated with snowfall and cold frontal systems. Although cold-dry events have been found to decrease, their underlying mechanisms require further investigation. Compound flooding encompasses storm surge and high rainfall, storm surge and sea level rise, storm surge and riverine flooding, and coastal and riverine flooding. Overall, there is a growing risk of compound flooding in the future due to changes in sea level rise, storm intensity, storm precipitation, and land-use-land-cover change. To understand processes and interactions underlying compound extremes, numerical models have been used to complement statistical modeling of the dependence between the components of compound extremes. While global climate models can simulate certain types of compound extremes, high-resolution regional models coupled with land and hydrological models are required to simulate the variability of compound extremes and to project changes in the risk of such extremes. In terms of statistical modeling of compound extremes, previous studies have used empirical approach, event coincidence analysis, multivariate distribution, the indicator approach, quantile regression and the Markov Chain method to understand the dependence, greatly advancing the state of science of compound extremes. Overall, the selection of methods depends on the type of compound extremes of interests and relevant variables.

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The transient sensitivity of sea level rise

Ocean Science ◽

10.5194/os-17-181-2021 ◽

2021 ◽

Vol 17 (1) ◽

pp. 181-186

Author(s):

Aslak Grinsted ◽

Jens Hesselbjerg Christensen

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Carbon Dioxide Emissions ◽

Radiative Forcing ◽

Climate Models ◽

Climate Model ◽

Greenhouse Gas Emission ◽

Rate Of Change ◽

Intergovernmental Panel ◽

Global Mean

Abstract. Recent assessments from the Intergovernmental Panel on Climate Change (IPCC) imply that global mean sea level is unlikely to rise more than about 1.1 m within this century but will increase further beyond 2100. Even within the most intensive future anthropogenic greenhouse gas emission scenarios, higher levels are assessed to be unlikely. However, some studies conclude that considerably greater sea level rise could be realized, and a number of experts assign a substantially higher likelihood of such a future. To understand this discrepancy, it would be useful to have scenario-independent metrics that can be compared between different approaches. The concept of a transient climate sensitivity has proven to be useful to compare the global mean temperature response of climate models to specific radiative forcing scenarios. Here, we introduce a similar metric for sea level response. By analyzing the mean rate of change in sea level (not sea level itself), we identify a nearly linear relationship with global mean surface temperature (and therefore accumulated carbon dioxide emissions) both in model projections and in observations on a century scale. This motivates us to define the “transient sea level sensitivity” as the increase in the sea level rate associated with a given warming in units of meters per century per kelvin. We find that future projections estimated on climate model responses fall below extrapolation based on recent observational records. This comparison suggests that the likely upper level of sea level projections in recent IPCC reports would be too low.

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A National Study on Protecting Infrastructure and Public Buildings against Sea Level Rise and Storm Surge

10.20944/preprints202108.0214.v1 ◽

2021 ◽

Author(s):

Paul Chinowsky ◽

Jacob Helman

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

Storm Surge ◽

The United States ◽

Design Guidelines ◽

National Study ◽

Multiple Perspectives ◽

Sea Levels ◽

Rising Sea Levels ◽

The Cost

The national study analyzes sea level rise (SLR) impacts based on 36 different SLR and storm surge scenarios across 5.7 million geographic locations and 3 time periods. Taking an approach based on engineering design guidelines and current cost estimates, the study details projected cost impacts for states, counties, and cities. These impacts are presented from multiple perspectives including total cost, cost per-capita, and cost per-square mile. The purpose of the study is to identify specific locations where infrastructure is vulnerable to rising sea levels. The study finds that Sea Level Rise (SLR) and minimal storm surge is a $400 billion threat to the United States by 2040 that includes a need for at least 50,000 miles of protective barriers. The research is limited in its scope to protecting coastal infrastructure with sea walls. Additional methods exist and may be appropriate in individual situations. The study is original in that it is a national effort to identify infrastructure that is vulnerable as well as the cost associated with protecting this infrastructure.

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Numerical Modeling of Saltwater Intrusion in the Rmel-Oulad Ogbane Coastal Aquifer (Larache, Morocco) in the Climate Change and Sea-Level Rise Context (2040)

Water ◽

10.3390/w13162167 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2167

Author(s):

Mohamed Jalal EL Hamidi ◽

Abdelkader Larabi ◽

Mohamed Faouzi

Keyword(s):

Climate Change ◽

Sea Level Rise ◽

Sea Level ◽

Coastal Aquifer ◽

Fresh Groundwater ◽

Sea Levels ◽

Groundwater Levels ◽

Rising Sea Levels ◽

Management Approaches ◽

And Sea Level

Many coastal aquifers have experienced seawater intrusion (SWI) into fresh groundwater aquifers. The principal causes of SWI include over-pumping and events such as climate change (CC) and rising sea levels. In northern Morocco, the Rmel-Oulad Ogbane coastal aquifer (ROOCA) supplies high-quality groundwater for drinking water and agriculture. This favorable situation has led to increased pumping, resulting in environmental challenges such as dropping water table and SWI. Furthermore, the climate has resulted in less recharge, with an estimated annual precipitation of 602 mm and an average temperature of 18.5 °C. The goal of this study is to determine how CC, over-pumping, and sea-level rise (SLR) affect SWI. Computational groundwater and solute transport models are used to simulate the spatial and temporal evolution of hydraulic heads and groundwater solute concentrations. The calibration is based on steady and transient groundwater levels from 1962 to 2040. SWI simulations show that the NW sector of the coastal area would be polluted, with the toe reaching 5.2 km inland with a significant salinity (15–25 g/L). To protect the fresh water in the reservoir from SWI, enhanced groundwater development and management approaches for this aquifer are required, such as artificial recharge from surface water.

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