Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Regardless of global warming, rising CO2 levels threaten marine life

12.03.2007
Like a piece of chalk dissolving in vinegar, marine life with hard shells is in danger of being dissolved by increasing acidity in the oceans.

Ocean acidity is rising as sea water absorbs more carbon dioxide released into the atmosphere from power plants and automobiles. The higher acidity threatens marine life, including corals and shellfish, which may become extinct later this century from the chemical effects of carbon dioxide, even if the planet warms less than expected.

A new study by University of Illinois atmospheric scientist Atul Jain, graduate student Long Cao and Carnegie Institution scientist Ken Caldeira suggests that future changes in ocean acidification are largely independent of climate change. The researchers report their findings in a paper accepted for publication in the journal Geophysical Research Letters, and posted on its Web site.

"Before our study, there was speculation in the academic community that climate change would have a big impact on ocean acidity," Jain said. "We found no such impact."

In previous studies, increasing levels of carbon dioxide in the atmosphere led to a reduction in ocean pH and carbonate ions, both of which damage marine ecosystems. What had not been studied before was how climate change, in concert with higher concentrations of carbon dioxide, would affect ocean chemistry and biology.

To investigate changes in ocean chemistry that could result from higher temperatures and carbon-dioxide concentrations, the researchers used an Earth-system model called the Integrated Science Assessment Model. Developed by Jain and his graduate students, the model includes complex physical and chemical interactions among carbon-dioxide emissions, climate change, and carbon-dioxide uptake by oceans and terrestrial ecosystems.

The ocean-surface pH has been reduced by about 0.1 during the past two centuries. Using ISAM, the researchers found ocean pH would decline a total of 0.31 by the end of this century, if carbon-dioxide emissions continue on a trajectory to ultimately stabilize at 1,000 parts per million.

During the last 200 years, the concentration of atmospheric carbon dioxide increased from about 275 parts per million to about 380 parts per million. Unchecked, it could surpass 550 parts per million by mid-century.

"As the concentration of carbon dioxide increases, ocean water will become more acidic; which is bad news for marine life," Cao said. "Fortunately, the effects of climate change will not further increase this acidity."

There are a number of effects and feedback mechanisms built into the ocean-climate system, Jain said. "Warmer water, for example, directly reduces the ocean pH due to temperature effect on the reaction rate in the carbonate system. At the same time, warmer water also absorbs less carbon dioxide, which makes the ocean less acidic. These two climate effects balance each other, which results in negligible net climate effect on ocean pH."

The addition of carbon dioxide into the oceans also affects the carbonate mineral system by decreasing the availability of carbonate ions. Calcium carbonate is used in forming shells. With less carbonate ions available, the growth of corals and shellfish could be significantly reduced.

"In our study, the increase in ocean acidity and decrease in carbonate ions occurred regardless of the degree of temperature change associated with global warming," Jain said. "This indicates that future changes in ocean acidity caused by atmospheric carbon-dioxide concentrations are largely independent of climate change."

That’s good news. The researchers’ findings, however, call into question a number of engineering schemes proposed as mitigation strategies for global warming, such as lofting reflective balloons into the stratosphere or erecting huge parasols in orbit. By blocking some of the sunlight, these devices would create a cooling effect to offset the warming caused by increasing levels of greenhouse gases.

"Even if we could engineer our way out of the climate problem, we will be stuck with the ocean acidification problem," Caldeira said. "Coral reefs will go the way of the dodo unless we quickly cut carbon-dioxide emissions."

Over the next few decades, we may make the oceans more acidic than they have been for tens of millions of years, Caldeira said. And that’s bad news.

James E. Kloeppel | EurekAlert!
Further information:
http://www.uiuc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>