CO2 pollution 'turning oceans more acid'

Yahoo Newws 30 Jan 09;

NICE, France (AFP) – Carbon dioxide (CO2) emissions must fall sharply to avoid inflicting acid damage to the world's marine ecosystems, more than 150 scientists warned Friday.

Acidification of ocean waters caused by greenhouse gases is already wreaking havoc on coral ecosystems and will have a huge knock-on impact on human communities, they said in a declaration released in the southern French city of Nice.

"We are deeply concerned by recent, rapid changes in ocean chemistry and their potential, within decades, to severely affect marine organisms, food webs, biodiversity and fisheries," the appeal to policymakers said.

"Ocean acidification is accelerating and severe damages are imminent."

The only way to stabilise, and eventually reverse, the trend is to reduce the amount of CO2 in the atmosphere, it said.

"The chemistry is so fundamental and changes so rapid and severe that impacts on organisms are unavoidable," said James Orr, a researcher at the Marine Environment Laboratories in Monaco.

"The questions are now how bad will it be and how soon will it happen."

Since industrialisation began in the 18th century, atmospheric levels of CO2 have risen by nearly 40 percent, thanks mainly to unbridled burning of coal, gas and oil.

Much of this CO2 is absorbed by the ocean, rendering it more acidic.

This process makes it harder for numerous marine organisms to build the calcium-based shells and skeletal structures on which they depend for survival. It also changes seawater chemistry, and has been shown to harm organisms ranging from oysters to sea urchins to squid.

CO2 in the atmosphere today aveages 385 parts per million (ppm). By mid-century, the concentration could easily exceed 550 ppm, which would decrease the rate at which coral forms by at least a third, studies have shown.

Even before that point, many coral reefs will already have seriously eroded.

Ocean acidification will also have a huge impact of human communities, the scientists warned.

In a chain of consequences, it will affect marine food webs and lead to substantial changes in commercial fish stocks, threatening protein supply and food security for tens of millions of people.

"Coral reefs provide fish habitat, generate billions of dollars in annual tourism, protect shorelines from erosion and flooding, and provide the foundation for tremendous biodiversity," the scientists said.

By 2050, more regions could become chemically inhospitable to reefs, they said.

The statement is called the Monaco Declaration, as it summarises work at an international symposium on the ocean staged in Monaco last October.

Acid oceans 'need urgent action'
BBC News 30 Jan 09;

The world's marine ecosystems risk being severely damaged by ocean acidification unless there are dramatic cuts in CO2 emissions, warn scientists.

More than 150 top marine researchers have voiced their concerns through the "Monaco Declaration", which warns that changes in acidity are accelerating.

The declaration, supported by Prince Albert II of Monaco, builds on findings from an earlier international summit.

It says pH levels are changing 100 times faster than natural variability.

Based on the research priorities identified at The Ocean in a High CO2 World symposium, held in October 2008, the declaration states:

"We scientists who met in Monaco to review what is known about ocean acidification declare that we are deeply concerned by recent, rapid changes in ocean chemistry and their potential, within decades, to severely affect marine organisms, food webs, biodiversity and fisheries."

'The other CO2 problem'

It calls on policymakers to stabilise CO2 emissions "at a safe level to avoid not only dangerous climate change but also dangerous ocean acidification".

The researchers warn that ocean acidification, which they refer to as "the other CO2 problem", could make most regions of the ocean inhospitable to coral reefs by 2050, if atmospheric CO2 levels continue to increase.

The also say that it could lead to substantial changes in commercial fish stocks, threatening food security for millions of people.

"The chemistry is so fundamental and changes so rapid and severe that impacts on organisms appear unavoidable," said Dr James Orr, chairman of the symposium.

"The questions are now how bad will it be and how soon will it happen."

Another signatory, Patricio Bernal, executive secretary of the UN Intergovernmental Oceanographic Commission, outlined how the marine research community intended to respond to the challenge.

"We need to bring together the best scientists to share their latest research results and to set priorities for research to improve our knowledge of the processes and of the impacts of acidification on marine ecosystems."

Prince Albert II used the declaration to voice his concerns, adding that he hoped the world's leaders would take the "necessary action" at a key UN climate summit later this year.

"I strongly support this declaration. I hope that it will be heard by all the political leaders meeting in Copenhagen in December 2009."