Not just temperture

Discussion in 'Environment' started by Old Rocks, Feb 10, 2010.

  1. Old Rocks
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    Old Rocks Diamond Member

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    Direct observations of basin-wide acidification of the North Pacific Ocean

    Global ocean acidification is a prominent, inexorable change associated with rising levels of atmospheric CO2. Here we present the first basin-wide direct observations of recently declining pH, along with estimates of anthropogenic and non-anthropogenic contributions to that signal. Along 152°W in the North Pacific Ocean (22–56°N), pH changes between 1991 and 2006 were essentially zero below about 800 m depth. However, in the upper 500 m, significant pH changes, as large as −0.06, were observed. Anthropogenic and non-anthropogenic contributions over the upper 800 m are estimated to be of similar magnitude. In the surface mixed layer (depths to ∼100 m), the extent of pH change is consistent with that expected under conditions of seawater/atmosphere equilibration, with an average rate of change of −0.0017/yr. Future mixed layer changes can be expected to closely mirror changes in atmospheric CO2, with surface seawater pH continuing to fall as atmospheric CO2 rises.
     
  2. Old Rocks
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    Old Rocks Diamond Member

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    Ocean acidification

    Ocean acidification
    Scientists are becoming increasingly worried about ocean acidification, a direct result of the increase in atmospheric CO2 levels. On 30 June 2005, the Royal Society of London published a Report on why this is important:

    carbon dioxide from the atmosphere dissolves in the ocean, and makes it acid.
    This is inevitable with high carbon dioxide, no fancy models are involved.
    The oceans are already 30% more acid that before fossil fuel burning started
    Acidification will kill corals, and probably make many other species (like squid) extinct
    The overall effects are unknown - there has been no period like this in the last 2 Million years
    The UK Royal Society has commented that �the effects of ocean acidifcation have potentially catastrophic consequences for marine life� .

    There is an equilibrium between atmospheric CO2 and the CO2 dissolved in seawater: as atmospheric levels increase, so do the levels of CO2 dissolved in the ocean waters, especially in the surface waters where most ocean life flourishes. The dissolved CO2 reacts with the seawater to form carbonic acid (H2CO3), increasing the water acidify (i.e. reducing pH). The exact results of this are unknown, but are potentially disasterous as common marine organisms, such as the fishes we use as food, may be unable to survive.


    It is important to note that the issue of seawater acidification is not related to global warming - there is no dispute about the reality of ocean acidification, only about the consequences.



    Researchers at Lawrence Livermore National Laboratory published a paper in the science journal Nature, suggesting that continued increases in atmospheric CO2 could alter ocean pH values - an effect greater than any experienced in the past 300 million years (Caldeira, K. & Wickett, M.E., 2003, Nature, v. 425. p. 365).
     
  3. dilloduck
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    dilloduck Diamond Member

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    oh shut up, rocks. :eusa_pray:
     
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  4. Old Rocks
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    Old Rocks Diamond Member

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    Princeton University Grand Challenge - The Biological Effects of Ocean Acidification

    The ongoing rise in atmospheric CO2 is increasing the dissolved CO2 concentration in the surface ocean, decreasing its pH, and consequently modifying the chemistry of many seawater constituents. These chemical changes in turn affect the ocean biota via a multitude of mechanisms. For example, the decrease in the degree of saturation of calcium carbonate makes it harder for calcifying organisms to precipitate their mineral structures. The decrease in pH changes the bioavailability of essential algal nutrients such as iron. Most directly, the increase in CO2 may change the composition of the biomass, e.g., its C:N ratio. Such biological effects potentially lead to major perturbations in marine biogeochemical cycles — including notably the biological export of CO2 to the abyss — and may provide a key feedback, negative or positive, on the CO2 buildup in the atmosphere and surface ocean. This research project is based on a series of mechanistic hypotheses on the biological effects of ocean acidification and comprises laboratory experiments as well as oceanographic field studies
     
  5. Old Rocks
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    Old Rocks Diamond Member

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    As good of an answer as any. But I won't:lol:
     
  6. dilloduck
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    dilloduck Diamond Member

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    any particular reason ?
     
  7. RetiredGySgt
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    RetiredGySgt Platinum Member

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    Cause we are DOOMED DOOMED he says.
     
  8. dilloduck
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    dilloduck Diamond Member

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    and he's saving us ?
     
  9. Old Rocks
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    Effects of Climate Change and Ocean Acidification on Living Marine Resources : Woods Hole Oceanographic Institution

    The Changing Ocean Environment
    Global warming should be called ocean warming, as more than 80% of the added heat resides in the ocean. Clear alterations to the ocean have already been detected from observations. The magnitude and patterns of these changes are consistent with an attribution to human activities and not explained by natural variability alone. Global average land and ocean surface temperatures increased at a rate of about 0.2°C/decade over the last few decades (Hansen et al., 2006), and ocean temperatures down to 3000 m (10,000 feet) depth are also on the rise. Averages rates of sea-level rise over the last several decades were 1.8±0.5 mm/y, with an even larger rate (3.1±0.7 mm/y) over the most recent decade. Higher precipitation rates are observed at mid to high latitude and lower rates in the tropics and subtropics. Corresponding changes have been measured in surface water salinities. One of the most striking trends is the decline in Arctic sea-ice extent, particularly over the summer. September Arctic ice-cover from 2002-2006 was 18% lower than pre-1980 ice-cover (Arctic Change: Ice - Sea Ice, and some models predict near ice-free conditions by 2040. Recent studies of the Greenland ice sheet highlight an alarming increase in surface melting over the summer, and percolation of that melt water to the base of the ice sheet where the melt-water could lubricate ice flow and potentially greatly accelerate ice loss and sea-level rise. These new findings have not been full incorporated into projected sea-level rise estimates, which thus may be underestimated.

    Over half of human carbon dioxide emissions to the atmosphere are absorbed by the ocean and land biospheres (Sarmiento and Gruber, 2002), and the excess carbon absorbed by the ocean results in increased ocean acidity. The physical and chemical mechanisms by which this occurs are well understood. Once carbon dioxide enters the ocean, it combines with water to form carbonic acid and a series of acid-base products, resulting in a lowering of pH values. The amount and distribution of human-generated carbon in the oceans are well determined from an international ocean survey conducted in the late 1980s and early 1990s (Sabine et al., 2004). The rate of ocean carbon uptake is controlled by ocean circulation. Most of the excess carbon is found in the upper few hundred meters of the ocean (upper 1200 feet) and in high-latitude regions, where cold dense waters sink into the deep ocean. Surface water pH values have already dropped by about 0.1 pH units from preindustrial levels and are expected to drop by an additional 0.14-0.35 units by the end of the 21st century (Orr et al., 2005).


    Climate Change and Ocean Acidification Impacts on Marine Ecosystems
    Climate change and ocean acidification will exacerbate other human influences on fisheries and marine ecosystems such as over-fishing, habitat destruction, pollution, excess nutrients, and invasive species. Thermal effects arise both directly, via effects of elevated temperature and lower pH on individual organisms, and indirectly via changes to the ecosystems on which they depend for food and habitat. Acidification harms shell-forming plants and animals including surface and deep-water corals, many plankton, pteropods (marine snails), mollusks (clams, oysters), and lobsters (Orr et al., 2005). Many of these organisms provide critical habitat and/or food sources for other organisms. Emerging evidence suggests that larval and juvenile fish may also be susceptible to pH changes. Marine life has survived large climate and acidification variations in the past, but the projected rates of climate change and ocean acidification over the next century are much faster than experienced by the planet in the past except for rare, catastrophic events in the geological record.
     
  10. Old Rocks
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    Old Rocks Diamond Member

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    No, I am presenting evidence for the minimally intelligent that we are creating serious problems for our species. Given the threshold, you may ignore anything I say.
     

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