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In coming decades, sea level rise associated with climate change will make some communities uninhabitable. Managed retreat, or planned relocation, is a proactive response prior to catastrophic necessity. Managed retreat has disruptive health, sociocultural, and economic impacts on communities that relocate. Health impacts include mental health, social capital, food security, water supply, sanitation, infectious diseases, injury, and health care access. We searched peer-reviewed and gray literature for reports on small island or coastal communities at various stages of relocation primarily due to sea level rise. We reviewed these reports to identify public health impacts and barriers to relocation. We identified eight relevant small communities in the USA (Alaska, Louisiana, and Washington), Panama, Fiji, Papua New Guinea, Solomon Islands, and Vanuatu. Affected populations range from 60 to 2700 persons and are predominantly indigenous people who rely on subsistence fishing and agriculture. Few reports directly addressed public health issues. While some relocations were successful, barriers to relocation in other communities include place attachment, potential loss of livelihoods, and lack of funding, suitable land, community consensus, and governance procedures. Further research is needed on the health impacts of managed retreat and how to facilitate population resilience. Studies could include surveillance of health indicators before and after communities relocate due to sea level rise, drought, or other environmental hazards. Lessons learned may inform relocation of both small and large communities affected by climate change. [ABSTRACT FROM AUTHOR]

Differentiating the impacts of climate change between 1.5°C and 2°C requires a regional and sector-specific perspective. Whereas for some regions and sectors the difference in climate variables might be indistinguishable from natural variability, other areas especially in the tropics and subtropics will experience significant shifts. In addition to region-specific changes in climatic conditions, vulnerability and exposure also differ substantially across the world. Even small differences in climate hazards can translate into sizeable impact differences for particularly vulnerable regions or sectors. Here, we review scientific evidence of regional differences in climate hazards at 1.5°C and 2°C and provide an assessment of selected hotspots of climate change, including small islands as well as rural, urban, and coastal areas in sub-Saharan Africa and South Asia, that are particularly affected by the additional 0.5°C global mean temperature increase. We interlink these with a review of the vulnerability and exposure literature related to these hotspots to provide an integrated perspective on the differences in climate impacts between 1.5°C and 2°C. [ABSTRACT FROM AUTHOR]

This study models shoreline retreat due to sea level rise by using geographic data and applies the model to future projections of decreases in beach area for 806 beaches in Japan. The model uses a foreshore slope (angle) based on data from a digital elevation model, and influence of the present simplified method for estimation of the shoreline retreat is examined through comparisons with previous studies at typical locations. The proposed method gives a distance of shoreline retreat due to sea level rise similar to that predicted using the Bruun rule for minimal retreat less than 30 m, but the difference becomes substantial for more extensive decreases. The decrease in beach area is projected for different sea level rises based on four Representative Concentration Pathway (RCP) scenarios from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The decrease in beach area becomes more severe for the RCP8.5 scenario, and the proposed method predicts that a third of current sandy beaches in Japan will disappear. The extent of the decrease depends not only on the sea-level-rise scenario but also on the SLR projection model. [ABSTRACT FROM AUTHOR]

Recent eustatic sea level rise (SLR) is one of the most striking manifestations of recent climate change as it directly impacts coastal activities and ecosystems. Although global SLR is well-known, local values differ due to vertical land motion, and changes in atmospheric pressure, ocean currents and temperatures. Although a reliable estimation of local SLR trends is needed to assess coastal zone vulnerabilities and plan adaptation strategies, instrumental records are usually short or sparse, especially in developing countries. Here we show that 210 Pb-dated sedimentary records from mangrove saltmarshes can provide useful decadal records of local SLR trends. We quantified sediment accretion rates in sediment cores from remote mangrove saltmarshes of the Yucatan Peninsula. Best SLR records were observed for cores collected near mean sea level (MSL). During most of the XX century the SLR rate ranged from 1-2 mm yr -1 , increased to a maximum of 4.5 ± 0.6 mm yr -1 and the acceleration was 0.13 mm yr -2 . Assuming either a constant SLR rate or acceleration, by the end of this century MSL level will be 39 cm or 91 cm above the present value. Both coastal infrastructures and ecosystems will be negatively affected by SLR and society will need to adapt relatively fast to the new conditions. [ABSTRACT FROM AUTHOR]

Cities are increasingly recognised as places in which climate change risks coalesce and from which climate change adaptation efforts are most likely to be mobilised. In an effort to reduce damages from storm surges and sea-level rise, the City of Cape Town municipal government set out to establish a coastal set-back line. This paper describes the process and highlights the potential for unanticipated conflict and resistance when notions of ‘best practice’ fail to consider local institutional interests and pre-existing legislation. This insight is important as coastal municipalities in South Africa look to implement set-back lines in compliance with the Integrated Coastal Management Act (Act 24 of 2008). McKenna et al. [McKenna, J., Cooper, A., & O'Hagan, A.M., Managing by principle: A critical analysis of the european principles of integrated coastal zone management (ICZM).Marine Policy, 32, 941–955. doi:10.1016/j.marpol.2008.02.005] elucidate the potential for conflicts and contradictions when applying the principles of Integrated Coastal Zone Management in Europe. Developing and a applying a set-back line for Cape Town's coastline was anticipated to be difficult given that the city remains socio-economically unequal and spatially segregated and that the coastline provides multiple different communities with amenities, resources and opportunities at the same time. What was not anticipated was the encountered resistance from within public sector directorates operating under the same policies. The paper suggests that differences in mentalities, technologies and resources (following Wood, J., and Shearing, C., (2007)Imagining security.Devon: Willan Publishing) make for subjective policy interpretations and applications by local officials. Recognising and managing these differences is critical if notions of ‘best practice’ prescribed at higher governance levels are to prove useful to climate change adaptation measures at the local scale. [ABSTRACT FROM PUBLISHER]

Changing climates are affecting biodiversity and natural systems, causing extinctions, range shifts, and phenological shifts. Efforts to forecast the spatial distribution and magnitude of these effects, however, have focused largely on direct effects of changing climates on species' distributional potential; recent work has considered secondary effects of warming climates via rising sea levels. Here, we present a first integration of the two dimensions of climate change effects on biodiversity, examining joint effects of marine intrusion and climate change on the distributional potential of seventy-six species of Mexican birds. The two phenomena are not related to one another—that is, a species seriously affected by one is not necessarily seriously affected by the other; however, the areas affected within species' distributions by the two phenomena tend to be complementary, compounding the negative effects. These results have implications for planning biodiversity conservation globally. [ABSTRACT FROM AUTHOR]