Oceans turning acidic, may have global impact

Oceans turning acidic, may have global impact
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First Published: Mon, Dec 14 2009. 01 15 AM IST

Critical issue: A file photo of the ocean off the Australian Antarctic territory. Seas and oceans absorb about one quarter of the carbon dioxide spewed into the atmosphere. AFP
Critical issue: A file photo of the ocean off the Australian Antarctic territory. Seas and oceans absorb about one quarter of the carbon dioxide spewed into the atmosphere. AFP
Updated: Mon, Dec 14 2009. 10 07 AM IST
Copenhagen: As deadlocked climate talks in Copenhagen prepared to enter a critical, fractious second week, a major new United Nations’ study showed how quickly the world could be running out of time.
The world’s biggest insurance policy against rapid warming, the oceans are soaking up atmospheric carbon dioxide at such a rate that their acidity—and so their ability to nurture an intricate planet-wide web of life—could increase 150% by 2050.
This dramatic increase, 100 times more than at any time in the last 20 million years, could cause “irreversible damage”, and highlights the direct link between climate change and the health of the oceans, said the study, released by the United Nations Convention on Biological Diversity, or CBD.
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Critical issue: A file photo of the ocean off the Australian Antarctic territory. Seas and oceans absorb about one quarter of the carbon dioxide spewed into the atmosphere. AFP
“Ocean acidification is irreversible on timescales of at least tens of thousands of years, and substantial damage to ocean ecosystems can only be avoided by urgent and rapid reductions in global emissions of CO2,” said Ahmed Djoghlaf, executive secretary of the Convention.
Djoghlaf said this was a “critical issue” that now needed to be included in the climate-change debate. That may not be easy with rich and poor countries failing to agree even on the language of a possible joint statement at the end of the week, much less key points such as cutting emissions and allocating money.
Seas and oceans absorb about one quarter of the carbon dioxide spewed into the atmosphere from the burning of fossil fuels, deforestation, and other human activities. Without this absorption, the global-warming crisis would be greater than it is now.
“This CBD study provides a valuable synthesis of scientific information on the impacts of ocean acidification, based on the analysis of more than 300 scientific literatures, and it describes an alarming picture of possible ecological scenarios and adverse impacts of ocean acidification on marine biodiversity,” Djoghlaf said.
The study predicts direct impact on commercial fishing. A more acidic ocean could mean that by century’s end some 70% of cold-water corals, a key refuge and feeding ground for species that fishermen catch, will be exposed to these corrosive waters.
Given the current emission rates—global emissions are up 30% since the Kyoto Protocol was signed 12 years ago—the effects will begin much sooner. The Arctic Ocean will lose essential minerals by 2032 and the southern seas by 2050. That means a disruption of food sources to many marine species, particularly to mussels, oysters, shrimp, crab and lobsters, which need calcium to grow.
Scientists say some species might benefit from such changes to the ocean, but overall the effects are likely to be negative, with attendant effects that could range from livelihood of coastal communities to planetary regulation of carbon dioxide.
“This publication...confirms again how great the stakes of sustainability are in the climate-change negotiations,” said Thomas E. Lovejoy, biodiversity chair of Washington DC’s Heinz Center for Science, Economics and the Environment, in the preface to the publication, officially titled Scientific Synthesis of the Impacts of Ocean Acidification on Marine Biological Diversity.
samar@hindustantimes.com
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First Published: Mon, Dec 14 2009. 01 15 AM IST