Many Atolls May be Uninhabitable Within Decades Due to Climate Change

Abstract

Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands’ shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought.

Coral Bleaching and Mortality in the Chagos Archipelago

“…It is clear that for these reefs to continue to accrete and survive in a productive way, the single most important issue to be addressed is that of periodic warming episodes that result in massive mortality of the reef building corals. Warming and sea-level rise will result in greater inundation of such islands (Storlazzi et al, 2015). The frequency of recurrence of warming water which impedes coral recovery will be critical to long term function of the Chagos reefs.…”

Sea Level Change and Coastal Climate Services: The Way Forward

“…Coastal vulnerability indicators [86] Detailed [66,81,87] to appropriate complexity modelling [88] Expected annual damages, adaptation needs [89][90][91][92][93][94] Critical infrastructures such as nuclear power plants [68,95] Critical settlements such as atoll islands [96,97] To assess local to regional SLR, coastal environmental evolution and societal development within a single framework.…”

La reconstruction de chaînes d'impacts au service de l'évaluation de la résilience des territoires et de la réduction des risques météo-marins : le cas des atolls des Tuamotu, Polynésie française

“…En effet, la résilience de l'écosystème récifal (qui joue un rôle central) face aux perturbations climatiques et anthropiques détermine directement celle des sociétés humaines, en raison de la forte dépendance que cellesci entretiennent avec les composantes physiques du système. C'est finalement l'un des rares territoires occupés par des sociétés humaines dont l'habitabilité future sera conditionnée par les réponses de l'écosystème-support aux pressions qu'il subit [Duvat, 2015 ;Gattuso et al, 2015 ;Storlazzi et al, 2015 ;Karnauskas, 2016 ;Werner et al, 2017]. Le type de perturbation examiné ici est le cyclone tropical.…”