Editing IPCC:AR6/SROCC/Chapter-4 (section)

==== 4.3.2.5 Towards a Synthetic Understanding of the Drivers of Exposure and Vulnerability ====

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Recent literature confirms that anthropogenic drivers played an important role, over the last century, in increasing exposure and vulnerability worldwide, and indicates that they will continue to do so in the absence of adaptation (medium evidence, high agreement). Some scholars argue that ‘even with pervasive and extensive environmental change associated with ~2oC warming, it is non-climatic factors that primarily determine impacts, response options and barriers to adapting’ (Ford et al., 2015, p. 1046). Although it is the interaction of climate and non-climate factors that eventually determine the level of impacts, acknowledging the role of a range of purely anthropogenic drivers has important implications for action. It suggests that major action can be taken now to enhance long-term adaptation prospects, notwithstanding uncertainty about local RSL rise and resultant impacts in the distant future (medium evidence, high agreement; Magnan et al., 2016 <sup>[[#fn:r1155|1155]]</sup> ). Acting on the human-driven drivers and root causes of vulnerability could yield co-benefits, for example by improving the state and condition of coastal ecosystems – and hence the capacity to cope with or adapt to SLR impacts – or, in deltaic regions, lowering the rates of anthropogenic subsidence and, in turn, minimising changes in sea level.

In addition, coastal ecosystem degradation is acknowledged as another major non-climatic driver of exposure and vulnerability (high confidence). The ability of coastal ecosystems to serve as a buffer zone between the sea and human assets (settlements and infrastructure), and to provide regulating services with respect to SLR-related coastal hazards (including inundation and salinisation), is progressively being lost due to coastal squeeze, pollution, and habitat and land degradation mainly due to land-use conversion.

We now better understand the diversity and interactions of the climate and non-climate drivers of exposure and vulnerability, as well as their dynamics over time (Bennett et al., 2016 <sup>[[#fn:r1156|1156]]</sup> ; Duvat et al., 2017 <sup>[[#fn:r1157|1157]]</sup> ). As a result, it is now realised how many context-specificities interact (including geography, economic development, social inequity, power and politics, and risk perceptions) and play a critical role in shaping the direction and influence of individual drivers and of their possible combinations on the ground (medium evidence, high agreement; Eriksen et al., 2015 <sup>[[#fn:r1158|1158]]</sup> ; Hesed and Paolisso, 2015 <sup>[[#fn:r1159|1159]]</sup> ; McCubbin et al., 2015 <sup>[[#fn:r1160|1160]]</sup> ). This also provides a stronger foundation to identify the range of possible responses (Sections 1.6.1, 1.6.2 and 4.4.3) to observed impacts and projected risks, as well as critical areas of action to enhance adaptation pathways (Section 4.4.4).

Recent studies (e.g., cited in Sections 4.3.2.1.1, 4.3.2.2, 4.3.2.4.2 and 4.3.2.4.4) also confirm AR5 conclusions that both developing and developed countries are exposed and vulnerable to SLR (high confidence).

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