Editing IPCC:AR6/WGII/Chapter-15 (section)

=== FAQ 15.1 | How is climate change affecting nature and human life on small islands, and will further climate change result in some small islands becoming uninhabitable for humans in the near future? ===

<div id="h2-21-siblings" class="h2-siblings"></div>

''Climate change has already affected and will increasingly affect biodiversity, nature’s benefits for people, settlements, infrastructure, livelihoods and economies on small islands. In the absence of ambitious human intervention to reduce emissions, climate change impacts are likely to make some small islands uninhabitable in the second part of the 21st century. By protecting and restoring nature in and around small islands as well as implementing anticipatory adaptation responses, humans can help reduce future risks to ecosystems and human lives on most small islands.''

Observed changes—including increases in air and ocean temperatures, increases in storm surges, heavy rainfall events, and possibly more intense tropical cyclones—are already reducing the number and quality of ecosystem services, thereby causing the disruption of human livelihoods, damage to buildings and infrastructure, and loss of economic activities and cultural heritage on small islands. Widespread observed impacts include severe coral reef bleaching events, such as that associated with the 2015–2016 El Niño season, the most damaging on record worldwide. Additionally, the 2017 Atlantic hurricane season was unusually characterised by sequential severe TCs that resulted in widespread cyclone-induced damage to ecosystems from the very interior of small islands to those of the ocean waters that surround them as well as damage to human settlements and economic activities within the whole Caribbean region. Although knowledge is limited regarding long-term increases in TC intensity, studies have shown that heavy rainfall and intense wind speed of individual TCs were increased by climate change. The combination of various climate events, such as TCs, extreme ocean waves, and El Niño or La Niña phases, with SLR causes increased coastal flooding, especially on low-lying atoll islands of the Indian and Pacific oceans.

The expected increased risk of such impacts under further climate change is significant. For example, some low-lying islands and areas may be extensively flooded at every high tide or during storms. As a result, their freshwater supplies and soils would be repeatedly contaminated by saltwater, with adverse cascading consequences for freshwater and terrestrial food supplies, biodiversity and ecosystems, and economic activities. It is unlikely that these locations would remain habitable unless such impacts are mitigated through reduction of heat-trapping greenhouse gas emissions or adaptation solutions that are acceptable for the populations of these islands. Acceptable adaptation options may be limited in these locations. Additionally, drought intensity may challenge freshwater security in some regions such as the Caribbean. Likewise, remote atoll islands where inhabitants rely on reef-derived food and other resources and that are at high risk of widespread coral reef degradation may become uninhabitable. Strategies to reduce risk may include substituting the consumption of vulnerable inshore reef resources by developing onshore aquaculture (fish farming), or promoting access to tuna and other pelagic fish, and/or importing food to meet nutritional needs. However, adoption of these strategies will depend on the acceptance of their local populations.

The intensity and timing of such impacts will be more severe under high warming futures compared to low warming futures accompanied by ambitious adaptation. Tailored, desirable and locally owned adaptation responses that incorporate both short- and long-term time horizons would certainly help to reduce future risks to nature and human life in small islands. Among the short-term measures frequently employed to address SLR and flooding are seawalls. Long-term measures include ecosystem-based adaptation such as mangrove replanting, relocation of coastal villages to upland sites, creation of elevated land through reclamation, revised building codes as part of a broader DRR strategy, shifting to alternative livelihoods and changes in farming and fishing practices.

<span id="faq-15.2-how-have-some-small-island-communities-already-adapted-to-climate-change"></span>