Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Modest CO2 cutbacks may be too little, too late for coral reefs

How much carbon dioxide is too much? According to United Nations Framework Convention on Climate Change (UNFCCC) greenhouse gases in the atmosphere need to be stabilized at levels low enough to "prevent dangerous anthropogenic interference with the climate system."

But scientists have come to realize that an even more acute danger than climate change is lurking in the world's oceans—one that is likely to be triggered by CO2 levels that are modest by climate standards.

Ocean acidification could devastate coral reefs and other marine ecosystems even if atmospheric carbon dioxide stabilizes at 450 ppm, a level well below that of many climate change forecasts, report chemical oceanographers Long Cao and Ken Caldeira of the Carnegie Institution's Department of Global Ecology in the journal Geophysical Research Letters.

The researchers' conclusions are based on computer simulations of ocean chemistry stabilized at atmospheric CO2 levels ranging from 280 parts per million (pre-industrial levels) to 2000 ppm. Present levels are 380 ppm and rapidly rising due to accelerating emissions from human activities, primarily the burning of fossil fuels.

This study was initiated as a result of Caldeira's testimony before a Congressional subcommittee on Fisheries, Wildlife and Oceans in April of 2007. At that time he was asked what stabilization level would be needed to preserve the marine environment, but had to answer that no such study had yet addressed that question. Cao and Caldeira's study helps fill the gap.

Atmospheric CO2 absorbed by the oceans' surface water produces carbonic acid, the same acid that gives soft drinks their fizz, making certain carbonate minerals dissolve more readily in seawater. This is especially true for aragonite, the mineral used by corals and many other marine organisms to grow their skeletons. For corals to be able to build reefs, which requires rapid growth and strong skeletons, the surrounding water needs to be highly supersaturated with aragonite.

"Before the industrial revolution, over 98% of warm water coral reefs were surrounded by open ocean waters at least 3.5 times supersaturated with aragonite" says Cao. "But even if atmospheric CO2 stabilizes at the current level of 380 ppm, fewer than half of existing coral reef will remain in such an environment. If the levels stabilize at 450 ppm, fewer than 10% of reefs would be in waters with the kind of chemistry that has sustained coral reefs in the past."

For the ecologically productive cold waters near the poles, the prospects are equally grim, says Cao. "At atmospheric CO2 levels as low as 450 ppm, large parts of the Southern Ocean, the Arctic Ocean, and the North Pacific would experience a rise in acidity that would violate US Environmental Protection Agency water quality standards." Under those conditions the shells of many marine organisms would dissolve, including those at the base of the food chain.

"If current trends in CO2 emissions continue unabated," says Caldeira, "in the next few decades, we will produce chemical conditions in the oceans that have not been seen for tens of millions of years. We are doing something very profound to our oceans. Ecosystems like coral reefs that have been around for many millions of years just won't be able to cope with the change."

"When you go to the seashore, the oceans seem huge," he adds. "It's hard to imagine we could wreck it all. But if we want our children to enjoy a healthy ocean, we need to start cutting carbon emissions now."

Ken Caldeira | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>