Researchers find unprecedented, man-made trends in oceans acidity

[OKIsItJustMe]

http://manoa.hawaii.edu/news/article.php?aId=4880

[font face=Times, Serif][font size=5]Researchers find unprecedented, man-made trends in oceans acidity[/font]

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Posted: Jan. 23, 2012

[font size=3]Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.

By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change.

The team of climate modelers, marine conservationists, ocean chemists, biologists and ecologists, led by Tobias Friedrich and Axel Timmermann at the International Pacific Research Center at the University of Hawai‘i at Mānoa, came to their conclusions by using Earth system models that simulate climate and ocean conditions 21,000 years back in time, to the Last Glacial Maximum, and forward in time to the end of the 21st century. In their models, they studied changes in the saturation level of aragonite (a form of calcium carbonate) typically used to measure ocean acidification. As acidity of seawater rises, the saturation level of aragonite drops. Their models captured the current observed seasonal and annual variations in this quantity in several key coral reef regions.

Today’s levels of aragonite saturation in these locations have already dropped five times below the pre-industrial range of natural variability. For example, if the yearly cycle in aragonite saturation varied between 4.7 and 4.8, it varies now between 4.2 and 4.3, which – based on another recent study – may translate into a decrease in overall calcification rates of corals and other aragonite shell-forming organisms by 15%. Given the continued human use of fossil fuels, the saturation levels will drop further, potentially reducing calcification rates of some marine organisms by more than 40% of their pre-industrial values within the next 90 years.

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http://dx.doi.org/10.1038/NCLIMATE1372

[phantom power]

1. more acidic than expected

[XemaSab]

2. +1

[Dead_Parrot]

3. Maybe if we get it acidic enough, it'll dissolve all the plastic we've dumped in it.

Tool monkeys FTW!

[OKIsItJustMe]

5. Oh, don’t worry about the plastic

http://blogs.discovermagazine.com/80beats/2009/08/21/plastic-is-more-biodegradable-than-we-thought-thats-bad/

[font face=Times, Serif][font size=5]Plastic Is More Biodegradable Than We Thought. (That’s Bad.)[/font]

[font size=3]Here’s the good news: Plastic may break down in the ocean in as little as a year, not 500 to 1,000 years as scientists previously thought. Now, the bad news: This degradation could be releasing harmful compounds such as bisphenol A (BPA) into the ocean, according to research presented at the American Chemical Society meeting on Wednesday.

Ocean-borne plastic, such as that in the vast Great Pacific Garbage Patch, has traditionally been viewed as an environmental hazard due to the danger it can pose to sea life and birds. But to find out more about how plastic behaves when in the ocean, researchers acquired water samples from Japan, India, Europe, the United States, and other locations. The results? All the water samples were found to contain derivatives of polystyrene, a common plastic used in disposable cutlery, Styrofoam, and DVD cases, among other things |National Geographic News|.

In another experiment simulating the breakdown of plastic in the ocean, researchers “found that plastic in the ocean actually decomposes as it is exposed to the rain and sun and other environmental conditions, giving rise to yet another source of global contamination that will continue into the future” |BBC|. As the plastic breaks down, it releases BPA, a compound shown to throw off rats’ hormone systems, along with another potentially harmful substance called styrene trimer. The toxins could not only pose a threat to marine life, but also to humans who eat seafood.

Still, some experts wonder if all of the ocean’s plastic really dissolves, since much of it may sink into the depths of the oceans where the water is generally calm, dark, and cold. For example, the plastic polystyrene is heavier than water, so it sinks. Because temperatures are much lower at the bottom of the ocean and there’s very little light to cause photodegredation, |ocean researcher Charles| Moore said it’s unlikely that the plastic would break down once it sunk. “Food doesn’t even biodegrade at the bottom of the ocean” |Wired.com|, Moore says. Meanwhile, pollution expert Joel Baker contends that the chemical releases are insignificant compared to the amount of water in the oceans. While he agrees that the plastic garbage in the ocean should be cleaned up, “There’s a little bit of hyperbole going on here,” Baker said |Wired.com|.[/font][/font]

[caraher]

4. And here's part of why "geoengineering" responses are inadequate

Unfortunately, by casting the global atmospheric carbon problem as "warming," rather than something like "fossil carbon," anything that appears to have a cooling effect can be sold as a "solution." Acidity is not going to fixed by sunshades in space or other technological silver bullet methods of reducing temperature.