Turning The Ocean Sour  

The Australian has an article on the looming danger of ocean acidifcation. This is a good one to run past any global warming skeptics out there that are happy to pretend that carbon emissions don't cause global warming - how about acid oceans ?

NOW that Ross Garnaut's draft report has been released, most of the climate change debate in Australia will focus on the economic effects of any emissions trading scheme.

However, there's another carbon problem, which will profoundly affect our oceans, that has received scant attention beyond a small band of marine scientists and is largely independent of global warming.

The public, aware of the role of carbon dioxide in climate change, doesn't know of its function in acidifying the oceans and the hundreds of years that would be required for recovery.

Ocean acidification refers to the natural process whereby carbon dioxide dissolves in the sea, forming a weak carbonic acid. The ocean is a major sink for atmospheric carbon dioxide and has absorbed about 48 per cent of the CO2 emitted by human activities since the pre-industrial age.

A recent report from the Antarctic Climate and Ecosystems Co-operative Research Centre claimed that carbon dioxide in the atmosphere is at its highest level in 650,000 years, and possibly 23 million years, and half has been dissolved in the oceans, making them more acidic.

Australia has a direct stake in the ocean acidification problem: it will affect every part of our marine environment. And our offshore estate has just become a lot bigger. Three months ago the UN Commission on the Limits of the Continental Shelf, while not accepting all bids, recognised Australia's claim to the continental shelf where it extends beyond our exclusive 200 nautical mile economic zone. This is a vast oceanic area: 2.5 million square kilometres, or 10 times the size of New Zealand and 20 times the size of Britain.

Rising levels of acidity in the oceans surrounding Australia could have a profound impact on marine industries and dire consequences for many Pacific Island communities, presenting strategic and humanitarian challenges.

Mounting levels of CO2 in the Southern Ocean has caused deep concern among scientists studying the long-term productivity of the world's oceans. Under conditions of increasing acidification, parts of the oceans will deteriorate and progressively become uninhabitable for certain types of plankton, central to the ocean food chain, and coral structures. The Southern Ocean is particularly important because it is very efficient at absorbing CO2 from the atmosphere: it's here where the first effects are being felt.

Ocean acidification is likely to have a cascading effect, reaching parts of the food chain such as fish and shellfish. Marine researchers are saying that a business-as-usual scenario of CO2 production will ultimately result in destruction of marine life on an enormous scale.