The report published in the journal Nature said the concentration of chemicals that absorb sound in the oceans has dropped off due to ocean pollution.

According to the report, low-frequency sound is absorbed mainly through the viscosity of the water and the presence of certain dissolved chemicals, but the chemicals’ concentration has reduced as a result of ocean acidification, caused by rising concentrations of carbon dioxide.

By using model simulations, the scientists found that increases in acidity could reduce seawater sound absorption by as much as 60 percent by 2100 in high latitude oceans.

Concern about the negative effect of the sea’s acidification has previously been concentrated on the reduced rate of calcification, such as in coral reefs.

“However, a less anticipated consequence of ocean acidification is its effect on underwater sound absorption,” said the scientist behind the report Tatiana Ilyina of the School of Ocean and Earth Science and Technology at the University of Hawaii in Honolulu.

High levels of low-frequency sound can have biological effects on marine life, including tissue damage, mass stranding of mammals such as whales and temporary loss of hearing in dolphins, according to the report. 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-12/22/content_12686967.htm

The report, published by the British medical review The Lancet in a special issue, said that global warming will imperil health through malaria, cholera, heatwaves and hunger, but these problems can be eased or avoided if actions on climate change are taken immediately.

The report examined policies to reduce emissions from households, transport, electricity generation and agriculture in both developed and developing countries.

Researchers found that cutting carbon dioxide emissions would reduce many types of air pollution, especially tiny particles that lodge in the lungs and cause direct health damage.

Other benefits could come from encouraging more exercise and less meat consumption to improve heart health, according to the report.

Some scientists praised the study and said the research was sound.

“The science is really excellent; the modeling is quite good,” said Dr. Paul Epstein of the Harvard School of Medicine’s Center for Health and the Global Environment. “It really takes the whole field a step farther.” 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-11/26/content_12543736.htm

Statkraft, a state-owned power group of Norway, is running the osmotic power plant prototype in a former chlorine factory on the banks of the Oslo fjord, about 60 kilometers south of Oslo.

Osmotic energy is based on the natural phenomenon of osmosis. When freshwater and seawater meet on either side of a membrane — a thin layer that retains salt but lets water pass — freshwater is drawn towards the seawater side.

Researchers found in the phenomenon of osmosis, there is pressure on the seawater side. And this pressure can be used to drive a turbine to produce electricity.

Osmosis has been used by industry to desalinate seawater, but Statskraft’s power plant at Tofte is the first time it has been used to produce energy.

“While salt might not save the world alone, we believe osmotic power will be an important part of the global energy portfolio,” said Baard Mikkelsen, the head of Statkraft.

Unlike other energy sources such as wind and solar power, osmotic power produces a stable electricity flow regardless of weather conditions, and could be installed almost anywhere where rivers flow into the ocean.

The worldwide potential of osmotic energy is estimated at 1,700 terrawatt hours per year, equivalent to half of the European Union’s energy production.

Statkraft said it hopes to build the first commercial osmotic power plant in 2015. The new plant will have a 25 megawatt capacity, enough to provide about 10,000 households with electricity. 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-11/25/content_12537054.htm

In the statement “Copenhagen Diagnosis” — a warning to next month’s UN climate summit in Copenhagen, the experts on Tuesday urged actions to keep down the rising greenhouse gas emissions by 2015 or 2020 to avoid the worst impacts of climate change.

“Climate change is accelerating beyond expectations,” the statement said, “accounting for ice-sheets and glaciers, global sea-level rise may exceed 1 meter by 2100, with a rise of up to 2 meters considered an upper limit.”

They said global carbon dioxide emissions from fossil fuels were almost 40 percent higher in 2008 than in 1990.

“There have been no significant changes in the underlying warming trend,” they said.
They also warned in the 64-page report that “delay in action risks irreversible damage.”

The statement was jointly issued by 26 experts. Many of them were on the UN Intergovernmental Panel on Climate Change, which in 2007 foresaw a sea level rise of 18-59 cm by 2100.

Copenhagen meeting will be held on Dec. 7-18, aiming to reach a new UN plan to succeed the Kyoto Protocol beyond 2012. 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-11/25/content_12536033.htm

The Catlin Arctic Survey team, led by explorer Pen Hadow, trekked through the northern part of the Beaufort Sea in the North Pole for 73 days earlier this year.

Across their 450-km route, the team found that most of the ice in the region is first-year ice that is only around 1.8 meters deep and will melt next summer. The region usually has contained thicker multiyear ice that does not melt so quickly.

“The Catlin Arctic Survey data supports the new consensus view… that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years.” said Professor Peter Wadhams, head of the polar ocean physics group at Cambridge University in Britain.

Martin Sommerkorn, senior climate change adviser for the World Wide Fund for Nature’s international Arctic programme, said the ice meltdown was happening “faster than we thought.”

“Such a loss of Arctic sea ice cover has recently been assessed to set in motion powerful climate feedbacks which will have an impact far beyond the Arctic itself,” he said.

But the short-term benefits of the melting could mean resource development and faster shipping. The Northwest Passage linking the Atlantic and Pacific oceans could one day become a regular shipping lane. 

On Xinhua Web site: http://news.xinhuanet.com/english/2009-10/15/content_12235952.htm