and
Rate
One of the first detailed datasets to examine how pH varied over a period of time at a temperate coastal location found that acidification was occurring much faster than previously predicted, with consequences for near-shore benthic ecosystems.[28][29] Thomas Lovejoy, former chief biodiversity advisor to the World Bank, has suggested that "the acidity of the oceans will more than double in the next 40 years. This rate is
100 times faster than any changes in ocean acidity in the last 20 million years, making it unlikely that marine life can somehow adapt to the changes."[30] It is predicted that, by the year 2100, the level of acidity in the ocean will reach the levels experienced by the earth 20 million years ago.[9][31]
Current rates of ocean acidification have been
compared with the greenhouse event at the Paleocene–Eocene boundary (about 55 million years ago) when surface ocean temperatures rose by 5–6 degrees Celsius. No catastrophe was seen in surface ecosystems, yet
bottom-dwelling organisms in the deep ocean experienced a major extinction. The current acidification is on a path to reach levels
higher than any seen in the last 65 million years,[32] and the
rate of increase is about ten times the rate that preceded the Paleocene–Eocene mass extinction. The current and projected acidification has been described as
an almost unprecedented geological event.[33] A National Research Council study released in April 2010 likewise concluded that "the level of acid in the oceans is
increasing at an unprecedented rate."[34][35] A 2012 paper in the journal Science examined the geological record in an attempt to find a historical analog for current global conditions as well as those of the future. The researchers determined that the
current rate of ocean acidification is faster than at any time in the past 300 million years.[36][37]
A review by climate scientists at the RealClimate blog, of a 2005 report by the Royal Society of the UK similarly highlighted the centrality of the rates of change in the present anthropogenic acidification process, writing:[38]
"The natural pH of the ocean is determined by a need to balance the deposition and burial of CaCO3 on the sea floor against the influx of Ca2+ and CO2−3 into the ocean from dissolving rocks on land, called weathering. These processes stabilize the pH of the ocean, by a mechanism called CaCO3 compensation...The point of bringing it up again is to note that
if the CO2 concentration of the atmosphere changes more slowly than this, as it always has throughout the Vostok record, the pH of the ocean will be relatively unaffected because CaCO3 compensation can keep up. The [present] fossil fuel acidification is much faster than natural changes, and so the acid spike will be more intense than the earth has seen in at least 800,000 years."
In the 15-year period 1995–2010 alone, acidity has increased 6 percent in the upper 100 meters of the Pacific Ocean from Hawaii to Alaska.[39] According to a statement in July 2012 by Jane Lubchenco, head of the U.S. National Oceanic and Atmospheric Administration
"surface waters are changing much more rapidly than initial calculations have suggested. It's yet another reason to be very seriously concerned about the amount of carbon dioxide that is in the atmosphere now and the additional amount we continue to put out."[40]
A 2013 study claimed acidity was increasing at a rate 10 times faster than in any of the evolutionary crises in the earth's history.[41]
REFERENCES
28) Wootton, J. T.; Pfister, C. A. and Forester, J. D. (2008). "Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset". Proceedings of the National Academy of Sciences 105 (48): 18848–18853. Bibcode:2008PNAS..10518848W. doi:10.1073/pnas.0810079105. PMC 2596240. PMID 19033205.
29) "Ocean Growing More Acidic Faster Than Once Thought; Increasing Acidity Threatens Sea Life". Science Daily. 2008-11-26. Retrieved 26 November 2008.
30) UN: Oceans are 30 percent more acidic than before fossil fuels
31) "What is Ocean Acidification". NOAA. Retrieved 24 August 2013.
32) "Rate of ocean acidification the fastest in 65 million years". Physorg.com. 2010-02-14. Retrieved 2013-08-29.
33) "An Ominous Warning on the Effects of Ocean Acidification by Carl Zimmer: Yale Environment 360". e360.yale.edu. Retrieved 2014-01-25.
34) Report: Ocean acidification rising at unprecedented rate
35) United States National Research Council, 2010. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean
36) "The Geological Record of Ocean Acidification". JournalistsResource.org, retrieved 14 March 2012
37) Hönisch, Bärbel; Ridgwell, Andy; Schmidt, Daniela N.; Thomas, E.; Gibbs, S. J.; Sluijs, A.; Zeebe, R.; Kump, L.; Martindale, R. C.; Greene, S. E.; Kiessling, W.; Ries, J.; Zachos, J. C.; Royer, D. L.; Barker, S.; Marchitto, T. M.; Moyer, R.; Pelejero, C.; Ziveri, P.; Foster, G. L.; Williams, B. (2012). "The Geological Record of Ocean Acidification". Science 335 (6072): 1058–1063. Bibcode:2012Sci...335.1058H. doi:10.1126/science.1208277. PMID 22383840.
38) The Acid Ocean – the Other Problem with CO2 Emission
39) How Acidification Threatens Oceans from the Inside Out
40) Huffington Post, 9 July 2012, "Ocean Acidification Is Climate Change's 'Equally Evil Twin,' NOAA Chief Says,"
http://www.huffingtonpost.com/2012/...limate-change_n_1658081.html?utm_hp_ref=green
41) Fiona Harvey, environment correspondent (2013-08-25). "Rising levels of acids in seas may endanger marine life, says study | Environment". The Guardian. Retrieved 2013-08-29.
42) Mitchell, M. J.; et al (2010). "A model of carbon dioxide dissolution and mineral carbonation kinetics". Proceedings of the Royal Society A 466 (2117): 1265–1290. doi:10.1098/rspa.2009.0349.
