Pengasidan lautan

Anggaran perubahan pH air laut disebabkan oleh manusia menghasilkan CO₂ pada antara 1700-an dengan 1990-an, daripada Projek Analisis Data Lautan Global dan Atlas Lautan Dunia

Pengasidan lautan ialah nama yang diberikan kepada pengurangan berterusan okay pH lautan Bumi, disebabkan oleh pengambilan karbon dioksida (CO₂) hasil kegiatan manusia daripada atmosfera Sebahagian daripada komponen karbon dioksida ini akan bertindak balas dengan air menghasilkan asid karbonat agar dapat mencapai serta mengekalkan keseimbangan kimia. Molekul-molekul asid karbonat pula bertindak balasi dengan molekul air membentuk ion bikarbonat dan ion hidronium sehingga meningkatkan keasidan laut.

Peningkatan keasidan air laut diperkirakan mendatangkan banyak akibat seperti penurunan mendadak metabolisme obor-obor jumbo (Dosidicus gigas), penurunan sistem keimunan kerang biru, serta pemutihan batu karang.

Pelarutan asid dalam air

CO₂ dilarutkan dalam air lautan lalu menambahkan ketumpatan ion hidrogen (H⁺) lalu mengurangkan pH laut seperti berikut:

CO_{2 (aq)} + H₂O H₂CO₃ HCO₃⁻ + H⁺ CO₃²⁻ + 2 H⁺.

Sejak bermulanya revolusi perindustrian, terdapat anggaran dibuat bahawa pH permukaan lautan telah menurun sedikit lebih daripada 0.1 unit dalam skala logaritma pH yang mewakili sebanyak 29% kenaikan H⁺. Penurunan lanjut dijangka sebanyak 0.3 hingga 0.5 pH units (an additional doubling to tripling of today's post-industrial acid concentrations) apabila mencecah 2100 selepas pengumpulan berterusan CO₂ antropogenik di lautan, di mana impak paling besar akan ketara pada batu-batu karang dan Lautan Selatan. These changes are predicted to accelerate as more anthropogenic CO₂ is released to the atmosphere and taken up by the oceans. Tahap perubahan kepada ciri-ciri kimia dalam lautan akan bergantung kepada tahap pengurusan dan pengurangan kesan dalam perubahan iklim yang diambil pihak yang bertanggungjawab.

pH permukaan lautan purata

Masa	pH	Perbedaan pH relatif kepada kadar praindustri	Sumber	Perubahan kadar H+ relatif kepada kadar praindustri
Zaman praindustri (abad ke-18)	8.179		analysed field
Recent past (1990s)	8.104	−0.075	field	+ 18.9%
Present levels	~8.069	−0.11	field	+ 28.8%
2050 (2×CO2 = 560 ppm)	7.949	−0.230	model	+ 69.8%
2100 (IS92a)	7.824	−0.355	model	+ 126.5%

Lihat juga

• Pam biologi
• Singki karbon dioksida
• Kedalaman pampasan karbonat
• Pam pelantar benua
• Gas rumah hijau
• Projek Analisis Data Lautan Global
• Maksimum Terma Paleosen–Eosen
• pH air laut
• Pam keterlarutan
• Impak persekitaran daripada industri arang batu

Rujukan

Bibliografi

• Clarke, L.; dll. (July 2007), Scenarios of Greenhouse Gas Emissions and Atmospheric Concentrations. Sub-report 2.1A of Synthesis and Assessment Product 2.1 by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC., USA: Department of Energy, Office of Biological & Environmental Research, diarkibkan daripada yang asal pada 2013-06-30, dicapai pada 2013-11-07
• Good, P.; dll. (2010), An updated review of developments in climate science research since IPCC AR4. A report by the AVOID consortium (PDF), London, UK: Committee on Climate Change, diarkibkan daripada yang asal (PDF) pada 2018-09-24, dicapai pada 2013-11-07 . Report website.
• UK Royal Society (September 2009), Geoengineering the climate: science, governance and uncertainty (PDF), London: UK Royal Society, ISBN 978-0-85403-773-5, RS Policy document 10/09. Report website.
• UNEP (November 2010), The Emissions Gap Report: Are the Copenhagen Accord pledges sufficient to limit global warming to 2° C or 1.5° C? A preliminary assessment, Nairobi, Kenya: United Nations Environment Programme (UNEP), ISBN 978-92-807-3134-7, diarkibkan daripada yang asal pada 2011-01-24, dicapai pada 2013-11-07
• US NRC (2011), America's Climate Choices. A report by the Committee on America's Climate Choices, US National Research Council (US NRC), Washington, DC, USA: National Academies Press, ISBN 978-0-309-14585-5
• WBGU (2006), Special Report: The Future Oceans – Warming Up, Rising High, Turning Sour (PDF), Berlin, Germany: WBGU, ISBN 3-936191-14-X, diarkibkan daripada yang asal (PDF) pada 2013-09-19, dicapai pada 2013-11-07. Report website.

Bacaan lanjut

• Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) (2008). Position analysis: CO₂ emissions and climate change: Ocean impacts and adaptation issues. ISSN: 1835–7911. Hobart, Tasmania.
• Cicerone, R. (2004). "The Ocean in a High CO₂ World" (PDF). Eos, Transactions, American Geophysical Union. American Geophysical Union. 85 (37): 351–353. Bibcode:2004EOSTr..85R.351C. doi:10.1029/2004EO370007. Diarkibkan daripada yang asal (PDF) pada 2007-03-05. Dicapai pada 2013-11-07.
• Doney, S. C. (2006). "The Dangers of Ocean Acidification". Scientific American. 294 (3): 58–65. doi:10.1038/scientificamerican0306-58. ISSN 0036-8733. PMID 16502612., (Article preview only).
• Feely, R. A. (2004). "Impact of Anthropogenic CO₂ on the CaCO₃ System in the Oceans". Science. 305 (5682): 362–366. Bibcode:2004Sci...305..362F. doi:10.1126/science.1097329. PMID 15256664.
• Harrould-Kolieb, E.; Savitz, J. (2008). "Acid Test: Can We Save Our Oceans From CO₂?". Oceana. Diarkibkan daripada yang asal pada 2011-10-09. Dicapai pada 2013-11-07.
• Henderson, Caspar (2006-08-05). "Ocean acidification: the other CO₂ problem". NewScientist.com news service.
• Jacobson, M. Z. (2005). "Studying ocean acidification with conservative, stable numerical schemes for nonequilibrium air-ocean exchange and ocean equilibrium chemistry". Journal of Geophysical Research – Atmospheres. 110: D07302. Bibcode:2005JGRD..11007302J. doi:10.1029/2004JD005220.
• Kim, Rakhyun E. (2012). "Is a New Multilateral Environmental Agreement on Ocean Acidification Necessary?" (PDF). Review of European Community & International Environmental Law. 21 (3): 243–258. doi:10.1111/reel.12000.x.
• Kleypas, J. A., R. A. Feely, V. J. Fabry, C. Langdon, C. L. Sabine, and L. L. Robbins. (2006). Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers: A Guide for Further Research Diarkibkan 2011-07-20 di Wayback Machine, report of a workshop held 18–20 April 2005, St. Petersburg, FL, sponsored by National Science Foundation, NOAA and the U.S. Geological Survey, 88pp.
• Kolbert, E. (2006-11-20). "The Darkening Sea: Carbon emissions and the ocean". The New Yorker.
• Riebesell, U., V. J. Fabry, L. Hansson and J.-P. Gattuso (Eds.). (2010). Guide to best practices for ocean acidification research and data reporting, 260 p. Luxembourg: Publications Office of the European Union.
• Sabine, C. L. (2004). "The Oceanic Sink for Anthropogenic CO₂". Science. 305 (5682): 367–371. Bibcode:2004Sci...305..367S. doi:10.1126/science.1097403. PMID 15256665.
• Stone, R. (2007). "A World Without Corals?". Science. 316 (5825): 678–681. doi:10.1126/science.316.5825.678. PMID 17478692.

Pautan luar

Sumber sains:

• How Acidification Threatens Oceans from the Inside Out Scientific American August 9, 2010 by Marah J. Hardt and Carl Safina
• Ocean acidification due to increasing atmospheric carbon dioxide, report by the Royal Society (UK)
• AR4 WG1 Chapter 5: Oceanic Climate Change and Sea Level, IPCC
• State of the Science FACT SHEET: Ocean acidification Diarkibkan 2011-07-15 di Wayback Machine, NOAA
• Carbon Dioxide Information Analysis Center Diarkibkan 2011-08-14 di Wayback Machine (CDIAC), the primary data analysis center of the U.S. Department of Energy (located at Oak Ridge National Laboratory)
• Ocean acidification introduction Diarkibkan 2011-07-22 di Wayback Machine, USGS
• Climate change threatening the Southern Ocean Diarkibkan 2009-12-31 di Wayback Machine, report by CSIRO
• The Ocean in a High CO₂ World, an international science symposium series
• The Acid Ocean – the Other Problem with CO₂ Emission, David Archer (scientist), a RealClimate discussion
• Regularly updated "blog" of ocean acidification publications and news, Jean-Pierre Gattuso
• Task Force on Ocean Acidification in the Pacific Diarkibkan 2007-06-07 di Wayback Machine, including recent presentations on ocean acidification, Pacific Science Association
• Ocean Acidification Diarkibkan 2011-07-24 di Wayback Machine, a multimedia, interactive site from The World Ocean Observatory
• Acidic Oceans: Why should we care? Perspectives in ocean science, Andrew Dickson, Scripps Institution of Oceanography
• Climate Change: Coral Reefs on the Edge Diarkibkan 2010-06-14 di Wayback Machine A video presentation by Prof. Ove Hoegh-Guldberg on impact of ocean acidification on coral reefs
• Life in the Sea Found Its Fate in a Paroxysm of Extinction April 30, 2012
• Ocean acidification virtual lab Diarkibkan 2013-10-07 di Wayback Machine
• Ocean Acidification: Starting with the Science, a booklet from the Division on Earth & Life Studies of the United States National Research Council (released April 2011)
• Ocean Acidification Diarkibkan 2013-02-24 di Wayback Machine, a United States National Academy of Sciences/ National Research Council website that includes downloadable figures and interviews with ocean scientists
• Ancient Ocean Acidification Intimates Long Recovery from Climate Change, July 22, 2010
• Acidification alters fish behavior: higher carbon dioxide in oceans may affect brain chemistry February 25, 2012 Science News
• Coordination of international research efforts and synthesis activities in ocean acidification. Diarkibkan 2013-10-10 di Wayback Machine IMBER/SOLAS

Tapak pendidikan:

• Understanding Ocean Acidification -- Educational Site from Channel Islands National Marine Sanctuary -- Education Team Diarkibkan 2013-10-10 di Wayback Machine

Projek sains:

• Dr. Francisco Chavez on Ocean Acidification – Smithsonian Ocean Portal
• European Project of Ocean Acidification (EPOCA), a 4-year-long EU initiative to investigate ocean acidification (initiated June 2008)
• Biological Impacts of Ocean Acidification (BIOACID), a German initiative funded by BMBF
• Ocean Acidification Research Programme (UKOARP), a 5-year-long UK initiative funded by NERC, Defra and DECC
• Research Program on Ocean Acidification Diarkibkan 2011-07-19 di Wayback Machine at the Cluster of Excellence "Future Ocean", Kiel
• Ocean Acidification Research Center Diarkibkan 2011-07-19 di Wayback Machine at University of Alaska Fairbanks

Sumber media popular:

• Threatening Oceans from the Inside Out: How Acidification Affects Marine Life, Scientific American
• "The Darkening Sea, article in The New Yorker magazine, Nov. 20, 2006 (requires registration)
• "Growing Acidity of Oceans May Kill Corals", Washington Post
• "Scientists Grapple with Ocean Acidification", ABC News
• "Ocean Acidification & Climate", by Clayton Sandell ABC News
• A World Without Whales? by Philippe Cousteau, The Huffington Post
• http://www.oceana.org/climate/solutions/oceana/acidtest/ Diarkibkan 2009-09-25 di Wayback Machine, Oceana
• The Acid Ocean Diarkibkan 2011-06-04 di Wayback Machine, Stanford University
• Sea Change (Parts One, Two, and Three), The Seattle Times

Video tentang Pengasidan Lautan:

• The Other CO₂ Problem, an EPOCA-commissioned educational animation created by students from Ridgeway School, Plymouth
• Acid Test: The Global Challenge of Ocean Acidification, by Natural Resources Defense Council
• A Sea Change: Imagine a world without fish, an award-winning documentary and related blog about ocean acidification
• Ocean Acidification in a Nutshell Diarkibkan 2011-01-14 di Wayback Machine, by Greenpeace Aotearoa New Zealand
• Ocean Acidification: An Ecosystem Facing Dissolution by GEOMAR I Helmholtz-Centre for Ocean Research Kiel

Kalkulator sistem karbonat

Pakej berikut menghitung keadaan sistem karbonat di dalam air laut (termasuk pH):

• CO2SYS Diarkibkan 2011-10-14 di Wayback Machine, a stand-alone executable (also available in a version for Microsoft Excel/VBA)
• seacarb Diarkibkan 2008-08-21 di Wayback Machine, a R package for Windows, Mac OS X and Linux (also available here)
• CSYS, a Matlab script