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Thursday, March 22, 2012

Ocean More Acidic

The warning comes from Barbel Honisch, oceanographer of the Lamont-Doherty Earth Observatory, Columbia University. "If the industry's carbon emissions continue to be in this pace, we may lose our loved ones organisms such as coral reefs, oyster, and salmon," he says (02/20/2012).

Honisch statement referring to the findings of an international research team that he led, the results are published in the latest Science journal. The team from the United States, Britain, Spain, Germany and the Netherlands are examined hundreds paleoceanografi, including fossils trapped in seafloor sediments millions of years old.
This 2002 photo shows bleached coral at Australia's Great Barrier Reef. Rising carbon dioxide levels in the world's oceans are killing the marine animals at an unprecedented rate. A new study has found that ocean acidification is the worst that it has been in at least the past 300 million years. (Picture from: http://www.csmonitor.com/)
The study is quite astonishing because the acidity of the ocean now ali faster than 56 million years ago. "Geological records show the acidification conditions today can not be compared with at least 300 million years of Earth history, and increase our chances of entering the unknown territory of the changes in marine ecosystems," said another researcher, Andy Ridgwell, from Bristol University.

Ocean acidification is the name given to the process of sea water pH levels to drop, which is now due to absorption of carbon dioxide in the atmosphere. Stack gas carbon dioxide in the air soared since the Industrial Revolution, which marked the use of fossil fuels such as oil and coal to power plants and power generation engines.

When the rate of increase of carbon dioxide in the atmosphere, the oceans will absorb it and convert it into carbonic acid. Consequently, the pH (measure of acidity) of seawater continued to decline, which means sea water becomes more acidic. In 2005, Jacobson noted in the surface ocean pH is estimated to drop from 8:25 to 8:14 from 1751 to 2004.

High levels of acid will dissolve the carbonate needed some marine organisms such as coral reefs, shellfish, or small snails, which become the food of the salmon. Many marine species will become extinct because of this condition.

Honisch and his colleagues found the condition of the earth in the past that are similar to current conditions occurred during the Paleocene-Eocene Thermal Maximum. Age during this period about 56 million years ago, or 9 million years after dinosaurs became extinct.

In this period, levels of carbon in Earth's atmosphere has doubled and encourage an increase in global temperatures. This condition is accompanied by the extinction of organisms in the sea. But now the seas into acid at least 10 times faster than in 56 million years ago, "said Honisch.

Increased carbon dioxide gas when it is triggered by a massive volcanic eruption, which started in the late Permian period (252 million years ago) and the late Triassic period about 201 million years ago. The scientists found that both phenomena are closely related to mass extinctions on Earth at that time.

According Honisch, biota living in the past it came and went. Extinct species are replaced by new species evolved. However, the current rate of warming the Earth reaches the point of the fastest and can remove a number of species of biota, especially those living in the oceans.

"But what we found today really stand out," said Honisch, an expert paleoseanografi. "The level of fossil fuel emissions today trigger a change in marine geochemistry of potentially unparalleled in the period 300 million years of history of our planet," said Honisch, is facing the marine ecosystem changes we do not know for sure.

In 2010, the Environmental Program of the United Nations issued a report warning that the particulars of risk posed by an increase in carbon emissions to the marine environment. The institute said the risk is greater than previously thought.

UN report calls for cutting carbon dioxide emissions significantly for mehgurangi acidification and support further research to quantify risks and identify more species are most vulnerable. *** [LIVESCIENCE | MAHARDIKA SATRIA HADI | KORAN TEMPO 3815]

90 Percent of Marine Species Disappeared
What caused the mass extinctions in the earth in the Permian period 250 million years ago? Computer simulations demonstrate high levels of carbon dioxide in the atmosphere has changed the oceans become acidic enough to can kill marine life.
The single-celled organism Stensioeina beccariiformis survived the mass extinction that killed the dinosaurs but went extinct 56 million years ago, when the oceans acidified due to a massive carbon dioxide release. (Picture from: http://www.livescience.com/)
"It's a trigger in the system that may have been pushed towards extinction," said Alvaro Montenegro, a climate modeler at St. Francis Xavier University in Antigonish, Nova Scotia. He and his colleagues describe their findings in the journal particulars latest Paleoceanography.

Computer simulations also showed another surprising thing. Montenegro says, at the end of the Permian period, more than 90 percent of marine species and three-quarters of land species has disappeared. The main cause is low oxygen levels in the oceans, rising levels of hydrogen sulfide compounds from the deep ocean, the cessation of nutrient cycling in the oceans, and large-scale eruption of the volcano.

Using a climate model developed at the University of Victoria, Montenegro and his colleagues make nine "variation" of the earth. They mix and match the composition of the continents, seafloor topography, and the level of carbon dioxide in the atmosphere. Then they run simulations to determine how carbon flows through the ocean and atmosphere.

In the atmosphere, Montenegro said carbon dioxide levels reach 3.000 parts per million (ppm), about 10 times greater than in pre-modern industry. Many gas dissolved in sea water and form carbonic acid and hydrogen ion release.
The computer model predicts the drop in pH since pre-industrial times. (Picture from: KORAN TEMPO 3815)
Ocean acidity is measured on a pH scale. The lower the number, the more acidic seawater. Ocean currently has a pH around 8.1. But the acidity of the oceans at the end of the Permian period drop to 7.3 and 7.1 regions around the equator near the poles.

"Rising ocean acidity more difficult for marine organisms use calcium carbonate to form a protective shell," said Montenegro. In the past, increased levels of carbon dioxide in the atmosphere from large volcanic eruptions, such as in Siberia.

Jonathan Payne, a paleobiology at Stanford University, stated, the faster the carbon dioxide accumulated in the atmosphere, the sooner an increase in ocean acidity. According to him, if the concentration of gases in the atmosphere increases rapidly Dengah, the model can be used Montenegro fair representation of the changing climate conditions in the Permian period. "In contrast, if the carbon dioxide accumulated slowly. Ocean may have a way to balance the acid levels in a certain way," said Payne.

Expressed a different opinion Lee Kump, a model maker at Pennsylvania State University in University Park. "The model that made Montenegro has not been contributing factors include carbon dioxide, such as weathering of the soil surface to the sea, which is also an important factor in the carbon cycle," he said.

If these factors are also included in the calculation, Kump said, the resulting models can describe the worst extinction in Earth's past. *** [SCIENCENEWS | MAHARDIKA SATRIA HADI | KORAN TEMPO 3815]
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