Editing IPCC:AR6/WGII/Chapter-3 (section)

===== 3.4.3.3.1 Evidence of natural adaptive capacity based on species’ responses to past climate variability =====

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Responses to abrupt climate change in the geological past suggest that adaptive capacity is limited for marine animals (Cross-Chapter Box PALEO in Chapter 1). Temperatures during the last Interglacial (~125 ka), which were warmer than today, led to poleward range shifts of reef corals ( ''medium confidence'' ) ( [[#Kiessling--2012|Kiessling et al., 2012]] ; [[#Jones--2019a|Jones et al., 2019a]] ). Temperature has also driven marine range shifts over multi-million-year time scales ( ''medium confidence'' ) ( [[#Gibbs--2016|Gibbs et al., 2016]] ; [[#Reddin--2018|Reddin et al., 2018]] ). Warming climates, even with low ocean-warming rates, inevitably decreased tropical marine biodiversity compared with middle latitudes ( ''high confidence'' ) ( [[#Mannion--2014|Mannion et al., 2014]] ; [[#Crame--2020|Crame, 2020]] ; [[#Yasuhara--2020|Yasuhara et al., 2020]] ; [[#Raja--2021|Raja and Kiessling, 2021]] ).

The paleorecord confirms that marine biodiversity has been vulnerable to climate warming both globally and regionally ( ''very high confidence'' ) (Cross-Chapter Box PALEO in Chapter 1; [[#Stanley--2016|Stanley, 2016]] ). In extreme cases of warming (e.g., &gt;5.2°C), marine mass extinctions occurred in the geological past, and there may be a relationship between warming magnitude and extinction toll ( ''medium confidence'' ) ( [[#Song--2021b|Song et al., 2021b]] ). A combination of warming and spreading anoxia caused marine extinctions in ancient episodes of rapid climate warming ( ''high confidence'' ) ( [[#Bond--2017|Bond and Grasby, 2017]] ; [[#Benton--2018|Benton, 2018]] ; [[#Penn--2018|Penn et al., 2018]] ; [[#Them%20II--2018|Them II et al., 2018]] ; [[#Chen--2019|Chen and Xu, 2019]] ). The role of ocean acidification in ancient extinctions is yet to be resolved ( ''low confidence'' ) ( [[#Clapham--2011|Clapham and Payne, 2011]] ; [[#Clarkson--2015|Clarkson et al., 2015]] ; [[#Jurikova--2020|Jurikova et al., 2020]] ; [[#Müller--2020|Müller et al., 2020]] ).

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