3.3.2.3 Impact distribution and new vulnerabilities

Crossing ESTPs is likely to exacerbate existing vulnerabilities to climate change, many of which are the result of historical and current inequities. It would potentially also reveal new vulnerabilities, shifting the distributional impacts of climate change and other environmental harms. Despite a growing understanding of tipping points, there remain substantial uncertainties regarding their temporal evolution and spatial extent, which poses a challenge for efforts to mitigate their impacts (Galaz et al., 2010; Barrett and Dannenberg, 2012). Common vulnerability indices used to identify the states and communities most vulnerable to climate change, and hence most in need for adaptation (Feldmeyer et al., 2021), do not currently take into account how risks and vulnerabilities may be reinforced or redistributed or by the crossing of different ESTPs (OECD, 2021).

While we might expect that the communities identified as most vulnerable to climate change impacts are also likely to be vulnerable to some of the ESTP impacts, others will fundamentally change expected climate patterns (notably AMOC collapse) and which populations are exposed or vulnerable. Indeed, while the Global North is often depicted as less climate-vulnerable than the Global South, crossing certain tipping points would have devastating impacts on both affluent and less-affluent communities. For example, crossing the extrapolar glaciers’ tipping points would heavily affect the European Alpine region, causing mega rockfalls, glacial lake outburst floods, and water shortages (see Table 3.3.1). Should the AMOC collapse, Europe would be one of the regions severely impacted, along with West Africa, India and the Amazon region (see Figure 3.3.2). The impacts of an AMOC collapse are relatively well understood, particularly in comparison to other ESTPs, as the Earth has experienced phases in its past when the AMOC was switched off. However, the projection in Figure 3.3.2 may change if several ESTPs are breached, creating compounding impacts.