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In the past two decades there have been fears that many low-lying atoll islands around the world could disappear as a consequence of climate change and sea level rise, leading to mass migration and threatening the existence of several island nations. Here we show how sea level rise does not inevitably lead to coastal areas becoming uninhabitable, and that humans have an innate and often underestimated capacity to adapt to changes in their environment. To do so we showcase three instances of human- and earthquake-induced land subsidence that have taken place in the 21st century, where the coastal/island areas are still inhabited despite the challenge of living with higher water levels: the Tohoku coastline following the 2011 Tohoku Earthquake Tsunami (subsidence ∼0.4–1.0 m), the present day situation of coastal areas in Jakarta due to ground water extraction (>5.0 m), and the islands of Tubigon, Bohol in central Philippines after the 2013 Bohol Earthquake (∼1.0 m). Humans are able to adapt and arrive at solutions even when confronted with cases of rapid rises in water levels, and thus it is likely that in the future vulnerable coastlines will be engineered and largely remain at present day locations, particularly in densely populated areas. If anything, around densely populated areas it is more likely that humans will continue to encroach on the sea rather than the reverse. We caution, however, that small islands are not homogeneous, and many are unlikely to respond to rising sea levels in the manner that atolls do (in fact, many might just resort to build at higher elevations). Where engineering and other adaptation responses become necessary, the financial and human resource requirements may well be beyond capacity of some small islands, which could lead to impoverishment and associated challenges in many communities.

Land subsidence has triggered severe coastal floods in Jakarta, whose mechanism has been extensively investigated by researchers and engineers. The government has also recognized this fact, which has partially contributed to the recent announcement that the capital will be relocated to East Kalimantan. However, it is not clear whether ordinary people perceive the progress of land subsidence as their own issue. To ascertain this, a field survey was conducted after a major coastal flood that took place in December 2017, which revealed that nearly half of the people living in a rapidly sinking coastal community were not aware of the ongoing land subsidence under their own houses. Severe flood and land subsidence were not strongly recognized as interlinked problems by local citizens. Rain-induced flooding is common in the community, and this may explain why a quarter of respondents did not fear the 2017 coastal flood, despite their houses being flooded, in some cases to a depth above their heads. Land subsidence has an adverse effect on flooding. Awareness building programs for normal citizens should be promoted, in order to articulate the significance of stopping groundwater extraction for mitigating land subsidence and the flooding it induces.

Located at the apex of the Coral Triangle, the Philippines is acknowledged as the world's center of shore fish biodiversity, and millions of Filipinos depend on these coastal resources for food and livelihood. In order to protect the coral reefs that form the base of many of these coastal ecosystems, Marine Protected Areas (MPAs) have been established throughout the country. However, although there is evidence of the benefits that come from establishing MPAs, there is still a need to improve their effectiveness by addressing the need for integrating environment, socio-economic, and governance pillars. In view of this, the present study used a multidisciplinary method of gathering data to measure the effectiveness of MPAs. The study also highlights the knowledge, attitude, and perception of stakeholders as the overlap between the three pillars of MPA sustainability, which were measured by conducting household surveys within the coastal community in which they are located. Based on the results of the data collection it was found that despite the efforts to inform the public of the existence of a protected area, a gap still remains between the knowledge of stakeholders and the actual coral cover/reef health. The Data Envelopment Analysis (DEA) also served as a useful framework to visualize the results of the newly proposed Sustainability Evaluation of Marine Protected Areas Index (SEMPAI). It is hoped that through future studies this index (though the multiple indicators that it uses) will be able to determine the efficiencies and inefficiencies of Decision-Making Units (DMUs), helping to improve the management and long-term sustainability of coastal settlements.

In-situ adaptation is commonly perceived to discourage mass migration, instead providing adverse incentives to continue building and living in risky areas. However, evidence from small islands in central Philippines experiencing frequent tidal flooding shows that in-situ adaptation can help enable mass migration by reducing vulnerability and increasing the resources needed for successful relocation. Using ecosystem-based adaptation, the island communities are able to increase their resilience to disasters, which could otherwise drive sudden and unplanned relocation. Using community-based adaptation or no regrets strategies such as education and vocational skills training, the younger generation of residents will be better able to find more mainland-based job opportunities, potentially enabling the natural depopulation of the island in the future.

Climate change will likely affect the effectiveness of future management of coastal ecosystems, impacting communities that reside within the coastal area. In order to formulate appropriate adaptation counter-measures it is important to understand the actual vulnerability of the communities that depend on these ecosystems. The present research proposes a tool for assessing the vulnerability of coastal communities to climate change by combining survey results with secondary and observed data available from national and local governments. The study focused on fisheries, given that they constitute the source of livelihood for many communities in developing countries such as Vietnam. The results showed that two coastal wards in Binh Thuan province, Vietnam, are highly vulnerable to the impacts of climate change, mainly because of their dependence on fisheries and the topography of the area. The seasonality of their source of livelihood affects the adaptive capacity of residents, making it less likely that they will be able to successfully adapt to changes in fishery resources that could be brought about by climate change. The results also showed that the communities are particularly vulnerable to sea level rise, given that they are both located in the immediate vicinity of the sea and are particularly low in elevation.