The response of coastal wetlands to sea-level rise during the twenty-first century remains uncertain. Global-scale projections suggest that between 20 and 90 per cent (for low and high sea-level rise scenarios, respectively) of the present-day coastal wetland area will be lost, which will in turn result in the loss of biodiversity and highly valued ecosystem services1,2,3. These projections do not necessarily take into account all essential geomorphological4,5,6,7 and socio-economic system feedbacks8. Here we present an integrated global modelling approach that considers both the ability of coastal wetlands to build up vertically by sediment accretion, and the accommodation space, namely, the vertical and lateral space available for fine sediments to accumulate and be colonized by wetland vegetation. We use this approach to assess global-scale changes in coastal wetland area in response to global sea-level rise and anthropogenic coastal occupation during the twenty-first century. On the basis of our simulations, we find that, globally, rather than losses, wetland gains of up to 60 per cent of the current area are possible, if more than 37 per cent (our upper estimate for current accommodation space) of coastal wetlands have sufficient accommodation space, and sediment supply remains at present levels. In contrast to previous studies1,2,3, we project that until 2100, the loss of global coastal wetland area will range between 0 and 30 per cent, assuming no further accommodation space in addition to current levels. Our simulations suggest that the resilience of global wetlands is primarily driven by the availability of accommodation space, which is strongly influenced by the building of anthropogenic infrastructure in the coastal zone and such infrastructure is expected to change over the twenty-first century. Rather than being an inevitable consequence of global sea-level rise, our findings indicate that large-scale loss of coastal wetlands might be avoidable, if sufficient additional accommodation space can be created through careful nature-based adaptation solutions to coastal management.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Blankespoor, B., Dasgupta, S. & Laplante, B. Sea-level rise and coastal wetlands. Ambio 43, 996–1005 (2014).
Spencer, T. et al. Global coastal wetland change under sea-level rise and related stresses: the DIVA Wetland Change Model. Global Planet. Change 139, 15–30 (2016).
Crosby, S. C. et al. Salt marsh persistence is threatened by predicted sea-level rise. Estuar. Coast. Shelf Sci. 181, 93–99 (2016).
Kirwan, M. L., Temmerman, S., Skeehan, E. E., Guntenspergen, G. R. & Fagherazzi, S. Overestimation of marsh vulnerability to sea level rise. Nat. Clim. Chang. 6, 253–260 (2016).
Schuerch, M., Vafeidis, A., Slawig, T. & Temmerman, S. Modeling the influence of changing storm patterns on the ability of a salt marsh to keep pace with sea level rise. J. Geophys. Res. Earth Surf. 118, 84–96 (2013).
French, J. R. Numerical simulation of vertical marsh growth and adjustment to accelerated sea-level rise, North Norfolk, U.K. Earth Surf. Process. Landf. 18, 63–81 (1993).
Morris, J. T., Sundareshwar, P. V., Nietch, C. T., Kjerfve, B. & Cahoon, D. R. Responses of coastal wetlands to rising sea level. Ecology 83, 2869–2877 (2002).
Enwright, N. M., Griffith, K. T. & Osland, M. J. Barriers to and opportunities for landward migration of coastal wetlands with sea-level rise. Front. Ecol. Environ. 14, 307–316 (2016).
Costanza, R. et al. Changes in the global value of ecosystem services. Glob. Environ. Change 26, 152–158 (2014).
Duarte, C. M., Losada, I. J., Hendriks, I. E., Mazarrasa, I. & Marba, N. The role of coastal plant communities for climate change mitigation and adaptation. Nat. Clim. Chang. 3, 961–968 (2013).
McLeod, E. et al. A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO2. Front. Ecol. Environ. 9, 552–560 (2011).
Temmerman, S. et al. Ecosystem-based coastal defence in the face of global change. Nature 504, 79–83 (2013).
Möller, I. et al. Wave attenuation over coastal salt marshes under storm surge conditions. Nat. Geosci. 7, 727–731 (2014).
Shepard, C. C., Crain, C. M. & Beck, M. W. The protective role of coastal marshes: a systematic review and meta-analysis. PLoS One 6, e27374 (2011).
Stark, J., Van Oyen, T., Meire, P. & Temmerman, S. Observations of tidal and storm surge attenuation in a large tidal marsh. Limnol. Oceanogr. 60, 1371–1381 (2015).
Aburto-Oropeza, O. et al. Mangroves in the Gulf of California increase fishery yields. Proc. Natl Acad. Sci. USA 105, 10456–10459 (2008).
Teuchies, J. et al. Estuaries as filters: the role of tidal marshes in trace metal removal. PLoS One 8, e70381 (2013).
Kirwan, M. L. & Megonigal, J. P. Tidal wetland stability in the face of human impacts and sea-level rise. Nature 504, 53–60 (2013).
Lovelock, C. E. et al. The vulnerability of Indo-Pacific mangrove forests to sea level rise. Nature 526, 559–563 (2015).
van Vuuren, D. P. et al. A new scenario framework for climate change research: scenario matrix architecture. Clim. Change 122, 373–386 (2014).
Kc, S. & Lutz, W. The human core of the shared socioeconomic pathways: population scenarios by age, sex and level of education for all countries to 2100. Glob. Environ. Change 42, 181–192 (2017).
Dijkstra, L. & Poelman, H. A Harmonised Definition of Cities and Rural Areas: the New Degree of Urbanisation; European Commission Working Paper WP 01/2014 (2014).
Day, J. W., Pont, D., Hensel, P. F. & Ibàñez, C. Impacts of sea-level rise on deltas in the Gulf of Mexico and the Mediterranean: the importance of pulsing events to sustainability. Estuaries 18, 636–647 (1995).
Yang, S. L. et al. Impact of dams on Yangtze River sediment supply to the sea and delta intertidal wetland response. J. Geophys. Res. Earth Surf. 110, F03006 (2005).
Ganju, N. K. et al. Spatially integrative metrics reveal hidden vulnerability of microtidal salt marshes. Nat. Commun. 8, 14156 (2017).
Spencer, K. L. et al. Physicochemical changes in sediments at Orplands Farm, Essex, UK following 8 years of managed realignment. Estuar. Coast. Shelf Sci. 76, 608–619 (2008).
Jankowski, K., Törnqvist, T. E. & Fernandes, A. M. Vulnerability of Louisiana’s coastal wetlands to present-day rates of relative sea-level rise. Nat. Commun. 8, 14792 (2017).
French, P. W. Managed realignment — the developing story of a comparatively new approach to soft engineering. Estuar. Coast. Shelf Sci. 67, 409–423 (2006).
Nicholls, R. J., Townend, I. H., Bradbury, A. P., Ramsbottom, D. & Day, S. A. Planning for long-term coastal change: experiences from England and Wales. Ocean Eng. 71, 3–16 (2013).
Peyronnin, N. et al. Louisiana’s 2012 coastal master plan: overview of a science-based and publicly informed decision-making process. J. Coast. Res. 67, 1–15 (2013).
Vafeidis, A. T. et al. A new global coastal database for impact and vulnerability analysis to sea-level rise. J. Coastal Res. 24, 917–924 (2008).
Hinkel, J. et al. Coastal flood damage and adaptation costs under 21st century sea-level rise. Proc. Natl Acad. Sci. USA 111, 3292–3297 (2014).
Vafeidis, A. T. et al. Water-level attenuation in broad-scale assessments of exposure to coastal flooding: a sensitivity analysis. Natural Hazards and Earth System Sciences Discussions https://doi.org/10.5194/nhess-2017-199 (2017).
Giri, C. et al. Status and distribution of mangrove forests of the world using earth observation satellite data. Glob. Ecol. Biogeogr. 20, 154–159 (2011).
McOwen, C. et al. A global map of saltmarshes. Biodivers. Data J. 5, e11764 (2017).
Kirwan, M. L., Walters, D. C., Reay, W. G. & Carr, J. A. Sea level driven marsh expansion in a coupled model of marsh erosion and migration. Geophys. Res. Lett. 43, 4366–4373 (2016).
Borchert, S. M., Osland, M. J., Enwright, N. M. & Griffith, K. T. Coastal wetland adaptation to sea level rise: quantifying potential for landward migration and coastal squeeze. J. Appl. Ecol. https://doi.org/10.1111/1365-2664.13169 (2018).
Gilman, E. L., Ellison, J., Duke, N. C. & Field, C. Threats to mangroves from climate change and adaptation options: a review. Aquat. Bot. 89, 237–250 (2008).
Torio, D. D. & Chmura, G. L. Assessing Coastal Squeeze of Tidal Wetlands. J. Coast. Res. 29, 1049–1061 (2013).
Kirwan, M. L. et al. Limits on the adaptability of coastal marshes to rising sea level. Geophys. Res. Lett. 37, L23401 (2010).
D’Alpaos, A., Mudd, S. M. & Carniello, L. Dynamic response of marshes to perturbations in suspended sediment concentrations and rates of relative sea level rise. J. Geophys. Res. Earth Surf. 116, F04020 (2011).
French, J. Tidal marsh sedimentation and resilience to environmental change: exploratory modelling of tidal, sea-level and sediment supply forcing in predominantly allochthonous systems. Mar. Geol. 235, 119–136 (2006).
Kirwan, M. L. & Guntenspergen, G. R. Influence of tidal range on the stability of coastal marshland. J. Geophys. Res. Earth Surf. 115, F02009 (2010).
Temmerman, S., Govers, G., Wartel, S. & Meire, P. Modelling estuarine variations in tidal marsh sedimentation: response to changing sea level and suspended sediment concentrations. Mar. Geol. 212, 1–19 (2004).
Church, J. A. et al. in Climate Change 2013: the Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds Stocker, T. F. et al.) 1137–1216 (Cambridge Univ. Press, Cambridge, 2013).
McFadden, L., Nicholls, R. J., Vafeidis, A. & Tol, R. S. J. Methodology for modeling coastal space for global assessment. J. Coast. Res. 23, 911–920 (2007).
Jarvis, A., Reuter, H. I., Nelson, A. & Guevara, E. Hole-Filled SRTM for the Globe Version 4; http://srtm.csi.cgiar.org/ (2008).
Nicholls, R. J., Hoozemans, F. & Marchand, M. Increasing flood risk and wetland losses due to global sea-level rise: regional and global analyses. Glob. Environ. Change 9, 69–87 (1999).
Nicholls, R. J. Coastal flooding and wetland loss in the 21st century: changes under the SRES climate and socio-economic scenarios. Glob. Environ. Change 14, 69–86 (2004).
Muis, S., Verlaan, M., Winsemius, H. C., Aerts, J. C. J. H. & Ward, P. J. A global reanalysis of storm surges and extreme sea levels. Nat. Commun. 7, 11969 (2016).
Titus, J. G. & Richman, C. Maps of lands vulnerable to sea level rise modeled elevations along the US Atlantic and Gulf coasts. Clim. Res. 18, 205–228 (2001).
Titus, J. G. & Wang, J. in Background Documents Supporting Climate Change Science Program Synthesis and Assessment Product 4.1 (EPA 430R07004) (eds Titus, J. G. & Strange, E. M.) (United States Environmental Protection Agency (EPA), Washington DC, 2008).
Vafeidis, A. T., Nicholls, R. J., McFadden, L., Hinkel, J. & Grasshoff, P. S. Developing a global database for coastal vulnerability analysis: design issues and challenges. Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci 35, 801–805 (2004).
Balke, T., Stock, M., Jensen, K., Bouma, T. J. & Kleyer, M. A global analysis of the seaward salt marsh extent: the importance of tidal range. Wat. Resour. Res. 52, 3775–3786 (2016).
Ellison, J. in Coastal Wetlands: an Integrated Ecosystem Approach (eds Perillo, G. M. E. et al.) 565–591 (Elsevier, Amsterdam, 2009).
McIvor, A. L., Spencer, T., Möller, I. & M., S. The Response of Mangrove Soil Surface Elevation to Sea Level Rise (The Nature Conservancy and Wetlands International, 2013).
McKee, K. L. & Patrick, W. H. The relationship of smooth cordgrass (Spartina alterniflora) to tidal datums: a review. Estuaries 11, 143–151 (1988).
Odum, W. E. Comparative ecology of tidal freshwater and salt marshes. Annu. Rev. Ecol. Syst. 19, 147–176 (1988).
Gray, A. J., Marshall, D. F. & Raybould, A. F. A century of evolution in Spartina anglica. Adv. Ecol. Res. 21 1–62 (1991).
Jones, C. D. et al. The HadGEM2-ES implementation of CMIP5 centennial simulations. Geosci. Model Dev. 4, 543 (2011).
Peltier, W. Global glacial isostasy and the surface of the ice-age earth: the ice-5G (VM2) model and GRACE. Annu. Rev. Earth Planet. Sci. 32, 111–149 (2004).
Meckel, T. A., Ten Brink, U. S. & Williams, S. J. Sediment compaction rates and subsidence in deltaic plains: numerical constraints and stratigraphic influences. Basin Res. 19, 19–31 (2007).
Syvitski, J. P. M. Deltas at risk. Sustain. Sci. 3, 23–32 (2008).
Ericson, J. P., Vörösmarty, C. J., Dingman, S. L., Ward, L. G. & Meybeck, M. Effective sea-level rise and deltas: causes of change and human dimension implications. Global Planet. Change 50, 63–82 (2006).
Pickering, M. D. et al. The impact of future sea-level rise on the global tides. Cont. Shelf Res. 142, 50–68 (2017).
Egbert, G. D., Ray, R. D. & Bills, B. G. Numerical modeling of the global semidiurnal tide in the present day and in the last glacial maximum. J. Geophys. Res. Oceans 109, C03003 (2004).
Center for International Earth Science Information Network (CIESIN) Columbia University, International Food Policy Research Institute (IFPRI), The World Bank & Centro Internacional de Agricultura Tropical (CIAT). Global Rural-Urban Mapping Project, Version 1 (GRUMPv1): Population Density Grid; http:// doi.org/10.7927/H4R20Z93 (accessed 22 July 2016).
Fricko, O. et al. The marker quantification of the Shared Socioeconomic Pathway 2: a middle-of-the-road scenario for the 21st century. Glob. Environ. Change 42, 251–267 (2017).
Barrot, G., Mangin, A. & Pinnock, S. Global Ocean Colour for Carbon Cycle Research, Product User Guide (ACRI-ST, Sophia-Antipolis, 2007).
Raabe, E. A. & Stumpf, R. P. Expansion of Tidal Marsh in Response to Sea-Level Rise: Gulf Coast of Florida, USA. Estuaries Coasts 39, 145–157 (2016).
Schieder, N. W., Walters, D. C. & Kirwan, M. L. Massive upland to wetland conversion compensated for historical marsh loss in Chesapeake Bay, USA. Estuaries Coasts 41, 940–951 (2018).
Smith, J. A. M. The role of Phragmites australis in mediating inland salt marsh migration in a mid-atlantic estuary. PLoS One 8, e65091 (2013).
Langston, A. K., Kaplan, D. A. & Putz, F. E. A casualty of climate change? Loss of freshwater forest islands on Florida’s Gulf Coast. Glob. Change Biol. 23, 5383–5397 (2017).
Anisfeld, S. C., Cooper, K. R. & Kemp, A. C. Upslope development of a tidal marsh as a function of upland land use. Glob. Change Biol. 23, 755–766 (2017).
Feagin, R. A., Martinez, M. L., Mendoza-Gonzalez, G. & Costanza, R. Salt marsh zonal migration and ecosystem service change in response to global sea level rise: a case study from an urban region. Ecol. Soc. 15, 14 (2010).
Gilman, E., Ellison, J. & Coleman, R. Assessment of mangrove response to projected relative sea-level rise and recent historical reconstruction of shoreline position. Environ. Monit. Assess. 124, 105–130 (2007).
Di Nitto, D. et al. Mangroves facing climate change: landward migration potential in response to projected scenarios of sea level rise. Biogeosciences 11, 857–871 (2014).
Rogers, K., Saintilan, N. & Copeland, C. Managed retreat of saline coastal wetlands: challenges and opportunities identified from the Hunter River Estuary, Australia. Estuaries Coasts 37, 67–78 (2014).
Stralberg, D. et al. Evaluating tidal marsh sustainability in the face of sea-level rise: a hybrid modeling approach applied to San Francisco Bay. PLoS One 6, e27388 (2011).
Craft, C., Broome, S. & Campbell, C. Fifteen years of vegetation and soil development after brackish-water marsh creation. Restor. Ecol. 10, 248–258 (2002).
Mossman, H. L., Brown, M. J. H., Davy, A. J. & Grant, A. Constraints on salt marsh development following managed coastal realignment: dispersal limitation or environmental tolerance? Restor. Ecol. 20, 65–75 (2012).
Mossman, H. L., Davy, A. J. & Grant, A. Does managed coastal realignment create saltmarshes with ‘equivalent biological characteristics’ to natural reference sites? J. Appl. Ecol. 49, 1446–1456 (2012).
Wolters, M., Garbutt, A., Bekker, R. M., Bakker, J. P. & Carey, P. D. Restoration of salt-marsh vegetation in relation to site suitability, species pool and dispersal traits. J. Appl. Ecol. 45, 904–912 (2008).
Nicholls, R. J. et al. Stabilization of global temperature at 1.5°C and 2.0°C: implications for coastal areas. Phil. Trans. A Math. Phys. Eng. Sci. 376, 20160448 (2018).
Song, J., Fu, X., Wang, R., Peng, Z.-R. & Gu, Z. Does planned retreat matter? Investigating land use change under the impacts of flooding induced by sea level rise. Mitig. Adapt. Strategies Glob. Change 23, 703–733 (2017).
Sadoff, C. W. et al. Securing Water, Sustaining Growth: Report of the GWP/OECD Task Force on Water Security and Sustainable Growth (Univ. Oxford, Oxford, 2015).
Mittermeier, R. A. et al. Wilderness and biodiversity conservation. Proc. Natl Acad. Sci. USA 100, 10309–10313 (2003).
Abel, N. et al. Sea level rise, coastal development and planned retreat: analytical framework, governance principles and an Australian case study. Environ. Sci. Policy 14, 279–288 (2011).
Kousky, C. Managing shoreline retreat: a US perspective. Clim. Change 124, 9–20 (2014).
Field, C. R., Dayer, A. A. & Elphick, C. S. Landowner behavior can determine the success of conservation strategies for ecosystem migration under sea-level rise. Proc. Natl Acad. Sci. USA 114, 9134–9139 (2017).
The Organisation for Economic Co-operation and Development (OECD). OECD Regional Typology (OECD, Paris, 2011).
This research was financially supported by the Deutsche Forschungsgemeinschaft (DFG) through the Cluster of Excellence 80 ‘The Future Ocean’, funded within the framework of the Excellence Initiative on behalf of the German federal and state governments, the personal research fellowship of M.S. (project number 272052902) and by the Cambridge Coastal Research Unit (Visiting Scholar Programme). Furthermore, this work has partly been supported by the European Union’s Seventh Programme for Research, Technological Development and Demonstration (grant no. 603396, RISES-AM project), the European Union’s Horizon 2020 Research and Innovation Programme (grant no. 642018, GREEN-WIN project), the US National Science Foundation (Coastal SEES 1426981 and NSF CAREER 1654374), Deltares and the UK Natural Environment Research Council. We thank M. Martin for support in editing the calibration data and G. Amable for statistical advice.
Nature thanks B. Glavovic, J. Woodruff and the other anonymous reviewer(s) for their contribution to the peer review of this work.
Extended data figures and tables
Green lines indicate segments in which the modelled sediment balances match the observed trends in wetland elevation change relative to sea-level rise3,4,19. Red segments indicate model mismatches. The frequency distributions for total suspended matter (TSM) and tidal range (TR) display the distributions of both parameters in matching (green bars) and mismatching segments (red bars), and how they compare to the overall frequency distributions of both parameters (blue bars). The overall frequency distribution only includes coastline segments where coastal wetlands are present. The displayed coastline was generated during the DINAS-COAST FP5-EESD EU project (EVK2-CT-2000-00084).
Results for all three SLR scenarios (RCP 2.6, low; RCP 4.5, medium; RCP 8.5, high) and a total of eight different model configurations. These include the upper and lower boundaries of the BAU (5 and 20 people km−2) and the upper boundaries of the NB 1 and NB 2 scenarios (150 and 300 people km−2) as defined in Extended Data Table 2 (solid lines). The dashed lines represent the four hypothetical scenarios, as characterized in Extended Data Table 2: (i) wetland migration only; (ii) sediment accretion only; (iii) maximum resilience; and (iv) no resilience. Source data
a, b, Absolute (a) and relative (b) changes in coastal wetland areas are displayed for a medium SLR scenario (RCP 4.5)), assuming the possibility of wetland inland migration everywhere, but in urban areas with a population density more than 300 people km−2. Population density is subject the population growth throughout the simulation period, following the Shared Socio-Economic Pathway SSP220,68. The displayed coastline was generated during the DINAS-COAST FP5-EESD EU project (EVK2-CT-2000-00084).
Extended Data Fig. 4 Flow diagram representing the overall structure of the global coastal wetland model.
Input parameters are shown on the left, output parameters are on the right. Net wetland change equals inland wetland gain minus seaward wetland loss.
The conversion of upland areas to coastal wetlands (if not inhibited by anthropogenic barriers) and the unconstrained seaward loss of coastal wetlands in response to sea-level rise is shown for an exemplary coastline segment (in western France). Inundation of terrestrial uplands follows the rising mean high water spring (MHWS) level between the time steps t1 and t2 (blue), whereas the unconstrained seaward loss follows the increase in mean sea level (MSL) when neglecting sediment accretion processes (red). To improve the clarity of the figure the actual MHWS level (2.54 m) and MSL rise are exaggerated.
Total relative sea-level rise (in m) for the medium SLR scenario (Extended Data Table 2) during the simulation period, including a delta subsidence rate of 2 mm yr−1 (2010–2100). Black coastlines indicate regions of relative sea-level rise similar to the global mean. The displayed coastline was generated during the DINAS-COAST FP5-EESD EU project (EVK2-CT-2000-00084).
This file contains Supplementary Methods, a Supplementary Discussion and Supplementary references. The Supplementary Methods include extended information on the underlying tidal data, the calibration procedure and detailed information on how the current-day coastal protection level has been calculated as one of key concepts for the definition of the business-as-usual scenario for human adaptation and accommodation space for coastal wetlands. The Extended Discussion section discusses the limitations of this model in detail.
About this article
Harmonising topographic & remotely sensed datasets, a reference dataset for shoreline and beach change analysis
Scientific Data (2019)
Salt and Wetland: Traditional Development Landscape, Land Use Changes and Environmental Adaptation on the Central Jiangsu Coast, China, 1450–1900
Nature Climate Change (2018)