Tuesday, April 6, 2010

Paleo-perspectives on ocean acidification - marine ecosystems under threat

Anthropogenic climate change is driving Ocean Acidification threatening marine ecosystems, according to a new scientific paper. "This will create conditions not seen on Earth for at least 40 million years. These changes are taking place at rates as much as 100 times faster than they ever have over the last tens of millions of years" Prof. Hoegh-Guldberg said, "Conditions are likely to become very hostile for calcifying species in the north Atlantic and Pacific over the next decade and in the Southern Ocean over the next few decades," the researchers warn.


Marine scientists in a new peer reviewed paper - Paleo-perspectives on ocean acidification - warn that the anthropogenic rise in atmospheric CO2 is driving fundamental and unprecedented changes in the chemistry of the oceans. They have declared ocean acidification to be the "Evil twin" to global warming. "Ocean conditions are already more extreme than those experienced by marine organisms and ecosystems for millions of years," the researchers say in the latest issue of the journal Trends in Ecology and Evolution (TREE). "This emphasises the urgent need to adopt policies that drastically reduce CO2 emissions."

The article was written by Professor Ove Hoegh-Guldberg of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland, and two spanish marine scientists from Barcelona: Professor Carles Pelejero from Institució Catalana de Recerca i Estudis Avançats (ICREA) and Institut de Ciències del Mar, and Dr Eva Calvo from Institut de Ciències del Mar, CSIC.

Professor Ove Hoegh-Guldberg gave a briefing in Copenhagen in December 2009 on the Extinction threat of Coral reefs and 10-20% of marine species if greehouse gases aren't brought down to 350ppm. Scientists call for emissions slashed to save Great Barrier Reef.

Marine scientists presented a briefing to Federal parliamentarians in Canberra on November 17, 2009. They presented an uncompromising warning that to have even a chance of saving the world's coral reefs from extensive damage caused by global warming, carbon emissions in industrialised countries need to be cut by 25% below the year 2000 levels by 2020 - and by 80-90% by 2050.

"The Great Barrier Reef (GBR) contributes $5.4 billion annually to the Australian economy - $5.1 billion from the tourism industry; $153 million from recreational activity; and $139 million from commercial fishing. The 'outstanding universal values' of the GBR, recognised by its inclusion on the World Heritage List in 1981, are now threatened by rapid climate change," Professor Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University told the briefing. (Audio from AUSSMC Online Science Briefing - Emissions reduction targets and the Great Barrier Reef (Nov 17, 2009)

Can someone please pass this on to Prime Minister Kevin Rudd, Climate Change Minister Penny Wong and Environment Minister Peter Garrett. It is going to be a close run race between ocean warming and ocean acidification killing the Great Barrier Reef and the destruction wrought from LNG and coal ships traversing the reef laden with coal or natural gas exported to further enhance anthropogenic rise in atmospheric CO2 and more ocean acidification.

Here is the full media release below:

Media Release - "Evil twin" threatens world's oceans, scientists warn



The rise in human emissions of carbon dioxide is driving fundamental and dangerous changes in the chemistry and ecosystems of the world's oceans, international marine scientists warned today.

"Ocean conditions are already more extreme than those experienced by marine organisms and ecosystems for millions of years," the researchers say in the latest issue of the journal Trends in Ecology and Evolution (TREE).

"This emphasises the urgent need to adopt policies that drastically reduce CO2 emissions."

Ocean acidification, which the researchers call the 'evil twin of global warming', is caused when the CO2 emitted by human activity, mainly burning fossil fuels, dissolves into the oceans. It is happening independently of, but in combination with, global warming.

"Evidence gathered by scientists around the world over the last few years suggests that ocean acidification could represent an equal - or perhaps even greater threat - to the biology of our planet than global warming," co-author Professor Ove Hoegh-Guldberg of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland says.

More than 30% of the CO2 released from burning fossil fuels, cement production, deforestation and other human activities goes straight into the oceans, turning them gradually more acidic.

"The resulting acidification will impact many forms of sea life, especially organisms whose shells or skeletons are made from calcium carbonate, like corals and shellfish. It may interfere with the reproduction of plankton species which are a vital part of the food web on which fish and all other sea life depend," he adds.

The scientists say there is now persuasive evidence that mass extinctions in past Earth history, like the "Great Dying" of 251 million years ago and another wipeout 55 million years ago, were accompanied by ocean acidification, which may have delivered the deathblow to many species that were unable to cope with it.

"These past periods can serve as great lessons of what we can expect in the future, if we continue to push the acidity the ocean even further" said lead author, Dr. Carles Pelejero, from ICREA and the Marine Science Institute of CSIC in Barcelona, Spain.

"Given the impacts we see in the fossil record, there is no question about the need to immediately reduce the rate at which we are emitting carbon dioxide in the atmosphere," he said further.

"Today, the surface waters of the oceans have already acidified by an average of 0.1 pH units from pre-industrial levels, and we are seeing signs of its impact even in the deep oceans", said co-author Dr. Eva Calvo, from the Marine Science Institute of CSIC in Barcelona, Spain.

"Future acidification depends on how much CO2 humans emit from here on - but by the year 2100 various projections indicate that the oceans will have acidified by a further 0.3 to 0.4 pH units, which is more than many organisms like corals can stand", Prof. Hoegh-Guldberg says.

"This will create conditions not seen on Earth for at least 40 million years". <> "These changes are taking place at rates as much as 100 times faster than they ever have over the last tens of millions of years" Prof. Hoegh-Guldberg says.

Under such circumstances "Conditions are likely to become very hostile for calcifying species in the north Atlantic and Pacific over the next decade and in the Southern Ocean over the next few decades," the researchers warn.

Besides directly impacting on the fishing industry and its contribution to the human food supply at a time when global food demand is doubling, a major die-off in the oceans would affect birds and many land species and change the biology of Earth as a whole profoundly, Prof. Hoegh-Guldberg adds.

Palaeo-perspectives on ocean acidification by Carles Pelejero, Eva Calvo and Ove Hoegh-Guldberg is published in the latest issue of the journal Trends in Ecology and Evolution (TREE), number 1232.

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Takver is a citizen journalist from Melbourne who has been writing on Climate Change issues and protests including Rising Sea Level, Ocean acidification, Environmental and social Impacts since 2004.