Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Acidifying oceans add urgency to CO2 cuts

07.07.2008
It's not just about climate change anymore. Besides loading the atmosphere with heat-trapping greenhouse gases, human emissions of carbon dioxide have also begun to alter the chemistry of the ocean—often called the cradle of life on Earth.

The ecological and economic consequences are difficult to predict but possibly calamitous, warn a team of chemical oceanographers in the July 4 issue of Science, and halting the changes already underway will likely require even steeper cuts in carbon emissions than those currently proposed to curb climate change.

Ken Caldeira of the Carnegie Institution's Department of Global Ecology, writing with lead author Richard Zeebe of the University of Hawaii and two co-authors*, note that the oceans have absorbed about 40% of the carbon dioxide (CO2) emitted by humans over the past two centuries. This has slowed global warming, but at a serious cost: the extra carbon dioxide has caused the ocean's average surface pH (a measure of water's acidity) to shift by about 0.1 unit from pre-industrial levels. Depending on the rate and magnitude of future emissions, the ocean's pH could drop by as much as 0.35 units by the mid-21st century.

This acidification can damage marine organisms. Experiments have shown that changes of as little as 0.2-0.3 units can hamper the ability of key marine organisms such as corals and some plankton to calcify their skeletons, which are built from pH-sensitive carbonate minerals. Large areas of the ocean are in danger of exceeding these levels of pH change by mid-century, including reef habitats such as Australia's Great Barrier Reef.

Most marine organisms live in the ocean's sunlit surface waters, which are also the waters most vulnerable to CO2-induced acidification over the next century as emissions continue. To prevent the pH of surface waters from declining more than 0.2 units, the current limit set by the U.S. Environmental Protection Agency in 1976, carbon dioxide emissions would have to be reduced immediately.

"In contrast to climate model predictions, such future ocean chemistry projections are largely model-independent on a time scale of a few centuries," the authors write, "mainly because the chemistry of CO2 in seawater is well known and changes in surface ocean carbonate chemistry closely track changes in atmospheric CO2."

Although the ocean's chemical response to higher carbon dioxide levels is relatively predictable, the biological response is more uncertain. The ocean's pH and carbonate chemistry has been remarkably stable for millions of years—much more stable than temperature.

"We know that ocean acidification will damage corals and other organisms, but there's just no experimental data on how most species might be affected," says Caldeira. "Most experiments have been done in the lab with just a few individuals. While the results are alarming, it's nearly impossible to predict how this unprecedented acidification will affect entire ecosystems." Reduced calcification will surely hurt shellfish such as oysters and mussels, with big effects on commercial fisheries. Other organisms may flourish in the new conditions, but this may include undesirable "weedy" species or disease organisms.

Though most of the scientific and public focus has been on the climate impacts of human carbon emissions, ocean acidification is as imminent and potentially severe a crisis, the authors argue.

"We need to consider ocean chemistry effects, and not just the climate effects, of CO2 emissions. That means we need to work much harder to decrease CO2 emissions," says Caldeira. "While a doubling of atmospheric CO2 may seem a realistic target for climate goals, such a level may mean the end of coral reefs and other valuable marine resources."

Ken Caldeira | EurekAlert!
Further information:
http://www.stanford.edu
http://www.CIW.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>