Peningkatan keasaman air laut: Perbedaan antara revisi
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{{CO2}} (g) + H<sub>2</sub>O (l) {{eqm}} {{CO2}} (aq) + H<sub>2</sub>O (l) {{eqm}} H<sub>2</sub>CO<sub>3</sub> (aq) {{eqm}} HCO<sub>3</sub><sup>−</sup> (aq) + H<sup>+</sup> (aq) {{eqm}} CO<sub>3</sub><sup>2−</sup> (aq) + 2 H<sup>+</sup> (aq) |
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'''Peningkatan keasaman air laut''' adalah peristiwa berkurangnya [[pH]] [[lautan]] yang berada di bumi, yang disebabkan oleh penyerapan [[karbon dioksida]] dari atmosfer (pH berkurang = keasaman meningkat).<ref name=cald03>{{Cite journal |last=Caldeira |first=K. |coauthors=Wickett, M. E. |year=2003 |title=Anthropogenic carbon and ocean pH |url=http://pangea.stanford.edu/research/Oceans/GES205/Caldeira_Science_Anthropogenic%20Carbon%20and%20ocean%20pH.pdf |journal=[[Nature (journal)|Nature]] |volume=425 |issue=6956 |pages=365–365 |doi=10.1038/425365a |pmid=14508477 |bibcode=2001AGUFMOS11C0385C |ref=harv}}</ref> Diperkirakan 30-40% karbon dioksida yang dilepaskan oleh manusia ke atmosfer larut ke perairan.<ref name=millero95>{{Cite journal |last=Millero|first=Frank J. |year=1995 |title=Thermodynamics of the carbon dioxide system in the oceans |url=http://www.sciencedirect.com/science/article/pii/001670379400354O | archiveurl = | archivedate = | journal=Geochimica et Cosmochimica Acta |volume=59 |issue=4 |pages=661–677 |doi= 10.1016/0016-7037(94)00354-O|pmid= |bibcode= 1995GeCoA..59..661M |ref=harv}}</ref><ref name=Feely04>{{cite journal |last=Feely |first=R. A. |coauthors=''et al.'' |title=Impact of Anthropogenic CO<sub>2</sub> on the CaCO<sub>3</sub> System in the Oceans |journal=Science |volume=305 |year=2004 |month=July |pages=362–366 |url=http://www.sciencemag.org/content/305/5682/362.abstract |bibcode = 2004Sci...305..362F |doi = 10.1126/science.1097329 |pmid=15256664 |issue=5682 |ref=harv}}</ref> Untuk mempertahankan [[kesetimbangan kimia]], sebagian akan bereaksi dengan air membentuk [[asam karbonat]]. Sebagian dari molekul asam karbonat akan beraksi dengan molekul air membentuk ion [[bikarbonat]] dan ion [[hydronium]], sehingga meningkatkan [[keasaman]] laut. Antara tahun 1751 hingga 1994, pH permukaan laut diperkirakan menurun dari 8.25 menjadi 8.14,<ref name=jacob05>{{cite journal | last=Jacobson | first=M. Z. | year=2005 | title=Studying ocean acidification with conservative, stable numerical schemes for nonequilibrium air-ocean exchange and ocean equilibrium chemistry | journal=[[Journal of Geophysical Research]] – Atmospheres | volume=110 | doi=10.1029/2004JD005220 | url=http://www.agu.org/journals/ABS/2005/2004JD005220.shtml | pages=D07302 | bibcode=2005JGRD..11007302J | ref=harv}}</ref> yang merupakan peningkatan konsentrasi ion hydronium sebanyak 30% di lautan.<ref name="pmid18536730">{{Cite journal |author=Hall-Spencer, J. M. |coauthors=Rodolfo-Metalpa, R.; Martin, S.; ''et al.'' |title=Volcanic carbon dioxide vents show ecosystem effects of ocean acidification |journal=[[Nature (journal)|Nature]] |volume=454 |issue=7200 |pages=96–9 |year=2008 |month=July |pmid=18536730 |doi=10.1038/nature07051 |bibcode=2008Natur.454...96H |ref=harv}}</ref><ref name="scor-int">[http://www.scor-int.org/OBO2009/A&O_Report.pdf Report of the Ocean Acidification and Oxygen Working Group, International Council for Science's Scientific Committee on Ocean Research (SCOR) Biological Observatories Workshop]</ref>
Peningkatan keasaman air aut diperkirakan memiliki beragam konsekuensi, seperti penurunan laju metabolisme [[cumi-cumi jumbo]] (''Dosidicus gigas''),<ref name=Rosa>{{cite journal |last=Rosa |first=R. |last2=Seibel |first2=B. |title=Synergistic effects of climate-related variables suggest future physiological impairment in a top oceanic predator |journal=P.n.a.s. |volume=105 |year=2008 |month= |pages=20776–20780 |url=http://www.pnas.org/content/105/52/20776.short |bibcode = 2008PNAS..10520776R |doi = 10.1073/pnas.0806886105 |issue=52 |ref=harv }}</ref> penurunan sistem imunitas kerang biru,<ref name=Bibby>{{cite journal |last=Bibby |first=R. |coauthors=''et al.'' |title=Effects of ocean acidification on the immune response of the blue mussel Mytilus edulis |journal=Aquatic Biology |volume=2 |year=2008 |month= |pages=67–74 |url=http://www.int-res.com/abstracts/ab/v2/n1/p67-74/ |doi=10.3354/ab00037 |ref=harv }}</ref> dan [[pemutihan koral]].
== Reaksi kimia ==
: <big>{{CO2}} (g) + H<sub>2</sub>O (l) {{eqm}} {{CO2}} (aq) + H<sub>2</sub>O (l) {{eqm}} H<sub>2</sub>CO<sub>3</sub> (aq) {{eqm}} HCO<sub>3</sub><sup>−</sup> (aq) + H<sup>+</sup> (aq) {{eqm}} CO<sub>3</sub><sup>2−</sup> (aq) + 2 H<sup>+</sup> (aq)</big>
Reaksi kimia lain juga terjadi sehingga kadar ion karbonat di lautan yang tersedia akan berkurang. Hal ini akan menyulitkan bagi hewan laut yang membutuhkan ion karbonat bagi pertumbuhan hidupnya seperti [[koral]] untuk proses kalsifikasi tubuhnya, dan beberapa jenis [[plankton]]. Struktur yang mengandung ion karbonat pun akan cepat rapuh karena larut oleh asam.<ref name=orr05>{{Cite journal |last=Orr |first=James C. |coauthors=''et al.'' |year=2005 |title=Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms |url=http://www.ipsl.jussieu.fr/~jomce/acidification/paper/Orr_OnlineNature04095.pdf |archiveurl=https://web.archive.org/web/20080625100559/http://www.ipsl.jussieu.fr/~jomce/acidification/paper/Orr_OnlineNature04095.pdf |archivedate=2008-06-25 |journal=[[Nature (journal)|Nature]] |volume=437 |issue=7059 |pages=681–686 |doi=10.1038/nature04095 |pmid=16193043 |bibcode=2005Natur.437..681O |ref=harv |access-date=2013-12-01 |dead-url=no }}</ref> Peningkatan keasaman lautan akan memicu gangguan pada [[rantai makanan]] yang ada pada dan terhubung dengan lautan.<ref>{{cite news|url=http://www.nytimes.com/2009/01/31/science/earth/31ocean.html|title=Rising Acidity Is Threatening Food Web of Oceans, Science Panel Says|author=Cornelia Dean|publisher=New York Times|date=January 30, 2009}}</ref><ref>{{cite journal|author= Robert E. Service |title= Rising Acidity Brings and Ocean Of Trouble |journal=Science|pages= 146–148 |volume= 337 |date= 13 July 2012|bibcode = 2012Sci...337..146S|doi= 10.1126/science.337.6091.146|pmid= 22798578|issue= 6091|ref= harv }}</ref> Sebanyak 105 [[akademi ilmu pengetahuan]] telah mengeluarkan rekomendasi untuk mengurangi emisi karbon dioksida global sebanyak setidaknya 50% dari tingkat emisi tahun 1990.<ref name="iap statement">{{Cite web | author=IAP | title=Interacademy Panel (IAP) Member Academies Statement on Ocean Acidification | date=June 2009 | url=http://www.interacademies.net/10878/13951.aspx | ref=harv | postscript={{inconsistent citations}} | access-date=2013-12-01 | archive-date=2013-08-06 | archive-url=https://web.archive.org/web/20130806073912/http://www.interacademies.net/10878/13951.aspx | dead-url=yes }}, Secretariat: TWAS (the Academy of Sciences for the Developing World), Trieste, Italy.</ref>
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