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

==== 3.5.5.2 Climate Regulation and Air Quality ====

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Climate regulation by the ocean depends on physical and biogeochemical processes (Sections 3.2–3.4) that create, move, and store heat, water vapour and other climate-active compounds including CO 2 , methane and dimethyl sulphide (WGI AR6 Chapter 6; [[#Szopa--2021|Szopa et al., 2021]] ). Over the 21st century, ocean heat and CO 2 uptake will continue (WGI AR6 SPMB4.1, B5.1; [[#IPCC--2021b|IPCC, 2021b]] ) and sea ice loss from warming will allow some additional CO 2 uptake ( [[#Armstrong--2019|Armstrong et al., 2019]] ), but the ocean will take up a smaller fraction of CO 2 emissions as atmospheric CO 2 concentrations rise ( ''high confidence'' ) (Table 3.26; WGI AR6 SPM B4.1; [[#IPCC--2021b|IPCC, 2021b]] ).

There is ''very limited evidence'' on climate-driven air-quality changes in the coastal zone. Increased humidity decreases the lifetime of ozone and increases particulate matter and indoor mould levels (USGCRP, 2016), potentially affecting near-shore air quality. However, coastal-zone air pollution can enhance coastal-climate impacts by increasing the risk of acid rain, which worsens ocean acidification (nitrogen oxides, sulphur oxides and mercury; [[#Doney--2010|Doney, 2010]] ; [[#Northcott--2019|Northcott et al., 2019]] ).

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