Editing Carbon dioxide (section)

=== Oceans ===
{{Main|Carbon cycle|Ocean acidification}}

==== Ocean acidification ====

Carbon dioxide dissolves in the ocean to form carbonic acid ({{chem2|H2CO3}}), bicarbonate ({{chem2|HCO3-}}), and carbonate ({{chem2|CO3(2-)}}). There is about fifty times as much carbon dioxide dissolved in the oceans as exists in the atmosphere. The oceans act as an enormous [[carbon sink]], and have taken up about a third of {{CO2}} emitted by human activity.<ref>{{cite web |date=29 November 2006 |title=How Long Can the Ocean Slow Global Warming? |url=http://www.whoi.edu/oceanus/viewArticle.do?id=17726 |url-status=live |archive-url=https://web.archive.org/web/20080104004633/http://www.whoi.edu/oceanus/viewArticle.do?id=17726 |archive-date=4 January 2008 |access-date=21 November 2007 |publisher=Oceanus |vauthors=Doney SC, Levine NM}}</ref>

{{excerpt|ocean acidification|paragraphs=1-2|file=no}}
[[File:Pterapod shell dissolved in seawater adjusted to an ocean chemistry projected for the year 2100.jpg|thumb|left|upright=1.35|Pterapod shell dissolved in seawater adjusted to an [[ocean chemistry]] projected for the year 2100]]
{{excerpt|Ocean acidification#Decreased calcification in marine organisms|paragraphs=1-2|file=no}}

==== Hydrothermal vents ====
Carbon dioxide is also introduced into the oceans through hydrothermal vents. The ''Champagne'' hydrothermal vent, found at the Northwest Eifuku volcano in the [[Mariana Trench]], produces almost pure liquid carbon dioxide, one of only two known sites in the world as of 2004, the other being in the [[Okinawa Trough]].<ref>{{cite journal |display-authors=6 |vauthors=Lupton J, Lilley M, Butterfield D, Evans L, Embley R, Olson E, Proskurowski G, Resing J, Roe K, Greene R, Lebon G |year=2004 |title=Liquid Carbon Dioxide Venting at the Champagne Hydrothermal Site, NW Eifuku Volcano, Mariana Arc |journal=American Geophysical Union |volume=2004 |issue=Fall Meeting |at=V43F–08 |bibcode=2004AGUFM.V43F..08L}}</ref> The finding of a submarine lake of liquid carbon dioxide in the Okinawa Trough was reported in 2006.<ref>{{cite journal |display-authors=6 |vauthors=Inagaki F, Kuypers MM, Tsunogai U, Ishibashi J, Nakamura K, Treude T, Ohkubo S, Nakaseama M, Gena K, Chiba H, Hirayama H, Nunoura T, Takai K, Jørgensen BB, Horikoshi K, Boetius A |date=September 2006 |title=Microbial community in a sediment-hosted {{CO2}} lake of the southern Okinawa Trough hydrothermal system |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=103 |issue=38 |pages=14164–14169 |bibcode=2006PNAS..10314164I |doi=10.1073/pnas.0606083103 |pmc=1599929 |pmid=16959888 |doi-access=free}} Videos can be downloaded at {{cite web |title=Supporting Information |url=http://www.pnas.org/content/103/38/14164.full?tab=ds |archive-url=https://web.archive.org/web/20181019001732/http://www.pnas.org/content/103/38/14164.full?tab=ds |archive-date=19 October 2018}}</ref>