Oceans Absorb Less Carbon Dioxide as Marine Systems Change

From: Ben Block, Worldwatch Institute, More from this Affiliate

The oceans are by far the largest carbon sink in the world. Some 93 percent of carbon dioxide is stored in algae, vegetation, and coral under the sea. But oceans are not able to absorb all of the carbon dioxide

released from the burning of fossil fuels. In fact, a recent study suggests that the oceans have absorbed a smaller proportion of fossil-fuel emissions, nearly 10 percent less, since 2000.

The study, published in the current issue of Nature, is the first to quantify the perceived trend that oceans are becoming less efficient carbon sinks. The study team, led by Columbia University oceanographer Samar Khatiwala, measured the amount of human-caused carbon dioxide emissions pumped into the oceans since 1765.

Industrial carbon dioxide emissions have increased dramatically since the 1950s, and oceans have until recently been able to absorb the greater amounts of emissions. Sometime after 2000, however, the rise in emissions and the oceans' carbon uptake decoupled. Oceans continue to absorb more carbon, but the pace appears to have slowed.

The reason is based in part on simple chemistry. Increased concentrations of carbon dioxide have turned waters more acidic, especially nearer to the poles. While carbon dioxide dissolves more readily in cold, dense seawater, these waters are less capable of sequestering the gas as the ocean becomes more acidic. The study revealed that the Southern Ocean, near Antarctica, absorbs about 40 percent of the carbon in oceans.

Article continues: http://www.worldwatch.org/node/6323

Ribbon Seal Protection Sought by Activists

From: Dan Joling, AP via Discovery News

Ribbon seals should be listed as threatened or endangered because global warming is quickly melting sea ice, which the seals depend on for several months each year, two environmental groups said in a lawsuit filed against the federal government in San Francisco Thursday.

The National Oceanic and Atmospheric Administration in December denied a listing under the Endangered Species Act for the seals found off the coasts of Alaska and Russia.

The Center for Biological Diversity and Greenpeace sued in U.S. District Court, claiming the agency ignored the best science available on global warming.

Article continues

Climate-change technology risks 'catastrophic' outcome

Risky and unproven climate-changing technologies could have "catastrophic consequences" for the earth and humankind if used irresponsibly, according to a new report.

Yet without drastic further cuts in carbon dioxide emissions, a geoengineering solution may offer the only hope of saving the world from disastrous run-away global warming, experts warned.

A report by the Royal Society, Britain's leading academic institution, looks at the feasibility and potential dangers of technologies designed to cool the earth.

They include artificial "trees" that suck carbon dioxide out of the air, and spraying sulphate particles high in the atmosphere to scatter the sun's rays into space. The scientists concluded that, although some approaches were possible, they had not yet been properly researched and posed serious potential dangers for the planet.

Professor John Shepherd, who chaired the Royal Society geoengineering working group, said: "It is an unpalatable truth that unless we can succeed in greatly reducing carbon dioxide emissions we are heading for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases."

"Our research found that some geoengineering techniques could have serious unintended and detrimental effects on many people and ecosystems — yet we are still failing to take the only action that will prevent us from having to rely on them."

Article continues: http://www.birminghampost.net/birmingham-business/birmingham-business-news/other-uk-business/2009/09/01/climate-change-technology-risks-catastrophic-outcome-report-65233-24585797/

Abrupt reversal detected in Arctic cooling trend

David Perlman, Chronicle Science Editor

The Arctic climate has been warmer over the past decade than during any 10-year period in 2,000 years, according to a study by an international research team that adds powerful new evidence that human-generated greenhouse gases have speeded the pace of the planet's recent warming.



The report from an international team of climate scientists concludes that climate change in the Arctic has accelerated since the Industrial Revolution, abruptly reversing a long-term worldwide cooling trend.

"The study provides a clear example of how increased greenhouse gases are now changing our climate," said Caspar Ammann of the National Center for Atmospheric Research in Boulder, Colo., a co-author of the report published Thursday in the journal Science.

To deduce the Arctic's decade-by-decade climate trend over the centuries, the leading scientists in the international study analyzed sediment cores in 14 Arctic lakes that revealed the varied growth rates of long-buried plants. They also studied Arctic tree rings to determine their growth rates and ages as well as ice cores from glaciers across the Arctic that showed patterns of relative warm and cold.

Researchers at other institutions, seeking to look for patterns of climate change even further back in time, used astronomical records to study the well-known wobble of the globe as it spins on its axis. They found that the Northern Hemisphere has long been moving away from the sun's warmth. During the summer solstice, the Northern Hemisphere is now a million kilometers - about 621,000 miles - farther away from the sun than it was 2,000 years ago, according to the scientist's computer models.

The result was a global period of relative cold that would have continued, the scientists found. But about 1850, at the beginning of the Industrial Age, the planet's climate began overcoming the cooling trend, and the Arctic climate has warmed decade by decade ever since as greenhouse gas emissions have increased, the scientists say.

Stephen Schneider, a Stanford climate expert and biologist who did not participate in the study, called the seven-year study, involving seven major research institutions in three nations, "a heroic effort."

The study, he said, "shows that nature has been, unfortunately, cooperating with theory and showing us on a long-time scale of millennia that the mainstream view is once again bolstered."

It is clear again, Schneider said, that anthropogenic influences - the increasing emission of greenhouse gases into the Earth's atmosphere - are the prime cause of global warming.


For the rest of the article go to:

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/09/04/MNB219HIRT.DTL&tsp=1

Arctic Ocean may be polluted soup by 2070

From: Kate Ravilious, NewScientist

WITHIN 60 years the Arctic Ocean could be a stagnant, polluted soup. Without drastic cuts in greenhouse-gas emissions, the Transpolar Drift, one of the Arctic's most powerful currents and a key disperser of pollutants, is likely to disappear because of global warming.

The Transpolar Drift is a cold surface current that travels right across the Arctic Ocean from central Siberia to Greenland, and eventually out into the Atlantic. It was first discovered in 1893 by the Norwegian explorer Fridtjof Nansen, who tried unsuccessfully to use the current to sail to the North Pole. Together with the Beaufort Gyre, the Transpolar Drift keeps Arctic waters well mixed and ensures that pollution never lingers there for long.

To better understand the dispersal of pollution in the Arctic Ocean, Ola Johannessen, director of the Nansen Environmental and Remote Sensing Center in Bergen, Norway, and his colleagues studied the spread of radioactive substances such as strontium-90 and caesium-137 from nuclear testing, bomb factories and nuclear power-plant accidents. Measurements taken between 1948 and 1999 were plugged into a high-resolution ocean circulation model and combined with a climate model to predict Arctic Ocean circulation until 2080.

Article continues