Ocean Acidification
What is ocean acidification? What is causing it?
Ocean acidification is the name given to the ongoing
decrease in the pH of the Earth's oceans.
The oceans absorbs abot 33% of the CO2 emitted to the atmosphere from
the burning of fuels. This valuable service comes at a steep ecological
cost - the acidification of the ocean. As CO2 dissolves in seawater,
the pH of the water decreases, which is called "acidification". Read
more at http://www.ocean-acidification.net/
A nonlinear calcification response to CO2-induced ocean
acidification by the coral Oculina arbuscula
August 2010
An information outlet on ocean acidification provided by
EPOCA, the European Project on Ocean Acidification
Anthropogenic
elevation of atmospheric pCO2 is predicted to cause the pH of surface
seawater to decline by 0.3–0.4 units by 2100 AD, causing a 50%
reduction in seawater [CO3 2−] and undersaturation with respect to
aragonite in high-latitude surface waters (Read More)
The impending catastrophe of ocean acidification
The Natural Resource Defense Council’s documentary ‘Acid
Test’ explores the dangers of rising ocean acidity.
By Stephanie Rogers
Mon, Jun 08 2009 at 12:51 PM EST
It’s officially World Oceans Day, an opportunity to
explore
the importance of our oceans and their rich diversity of life. It’s
also a chance to highlight what Daniel Hinerfeld of the Natural
Resources Defense Council (NRDC) calls "the scariest environmental
problem you’ve never heard of".
Hinerfeld is the writer, co-director and executive producer of "Acid
Test: The Challenge of Ocean Acidification", a documentary narrated by
Sigourney Weaver. He says that although he has worked at NRDC for six
years, he knew virtually nothing about ocean acidification before
starting work on the film -- and he’s betting that a lot of you haven’t
heard of it, either.
Read more
The findings of the study on ocean acidification and its
impact on oysters is published in the open access journal PLoS One. (Public Library of Science)
The world's oceans - getting warmer and more acidic
The world's oceans are warming and becoming more acidic.
80%
of the heat from human activity has ended up in the ocean. The
acidification has been happening since the industrial revolution
started in the 1850s. Even if we stop emitting CO2 today, there's a
total doubling of hydrogen ions backlogged in the atmosphere and built
into the system.
The effects will be dire for animals which build shells
if the
acidity of the ocean increases. Pterapods are small snails and in the
lab it has been shown they won't be able to survive in a more acidic
ocean. They play an important part of the marine food web. Tony Haymet
says we're running a large irreversible experiment with unknown
consequences. Full Story at The Science Show
Dissolving CO2 in seawater also increases the hydrogen
ion
(H+) concentration in the ocean, and thus decreases ocean pH. Caldeira
and Wickett (2003) placed the rate and magnitude of modern ocean
acidification changes in the context of probable historical changes
during the last 300 million years.
Since the industrial revolution began, it is estimated
that surface
ocean pH has dropped by slightly less than 0.1 units (on the
logarithmic scale of pH; approximately a 25% increase in H+), and it is
estimated that it will drop by a further 0.3 - 0.5 units by 2100 as the
ocean absorbs more anthropogenic CO2. These changes are predicted to
continue rapidly as the oceans take up more anthropogenic CO2 from the
atmosphere, the degree of change to ocean chemistry, for example ocean
pH, will depend on the mitigation or emissions pathway society takes.
Note that, although the ocean is acidifying, its pH is still greater
than 7 (that of neutral water), so the ocean could also be described as
becoming less basic.
Although the largest changes are expected in the future,
a report from
NOAA scientists found large quantities of water undersaturated in
aragonite are already upwelling close to the Pacific continental shelf
area of North America. Continental shelves play an important role in
marine ecosystems since most marine organisms live or are spawned
there, and though the study only dealt with the area from Vancouver to
northern California, the authors suggest that other shelf areas may be
experiencing similar effects. Similarly, one of the first detailed
datasets examining temporal variations in pH at a temperate coastal
location found that acidification was occurring at a rate much higher
than that previously predicted, with consequences for near-shore
benthic ecosystems. Source Wikipedia
The Acid Ocean – the Other Problem with CO2 Emission
2 July 2005
The Royal Society has just issued a summary report on
the effects of CO2 on the pH chemistry of seawater and aquatic
organisms and ecosystems. In addition to its pivotal role in the
atmosphere in the regulation of global climate, CO2 and its sister
chemical species, HCO3- and CO32- comprise the carbonate buffer system
which regulates the pH of seawater. The new report can be found here.
Acidifying the ocean is particularly detrimental to organisms that
secrete shell material made of CaCO3, such as coral reefs and a type of
phytoplankton called coccolithophorids [Kleypas et al., 1999]. The
ocean pH change will persist for thousands of years. Because the fossil
fuel CO2 rise is faster than natural CO2 increases in the past, the
ocean will be acidified to a much greater extent than has occurred
naturally in at least the past 800,000 years [Caldeira and Wicket,
2003]. Source; http://www.realclimate.org/index.php?p=169
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