Thursday, October 03, 2013

Our Oceans Are In Peril And, Yes, You Can Thank Manmade Carbon Emissions

Our oceans haven't been this acidic in Three Hundred Million Years.   And our carbon emissions are the culprit.   The only reason we don't have massively greater concentrations of atmospheric greenhouse gases is that our oceans have served as a huge sink for carbon dioxide.   Now we're facing a mass extinction of key marine species.

In the starkest warning yet of the threat to ocean health, the International Programme on the State of the Ocean (IPSO) said: "This [acidification] is unprecedented in the Earth's known history. We are entering an unknown territory of marine ecosystem change, and exposing organisms to intolerable evolutionary pressure. The next mass extinction may have already begun." It published its findings in the State of the Oceans report, collated every two years from global monitoring and other research studies.
Alex Rogers, professor of biology at Oxford University, said: "The health of the ocean is spiralling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth."
This isn't one of those "we'd better mind our ways, or else" warnings.
In absorbing carbon and heat from the atmosphere, the world's oceans have shielded humans from the worst effects of global warming, the marine scientists said. This has slowed the rate of climate change on land, but its profound effects on marine life are only now being understood.
...Current rates of carbon release into the oceans are 10 times faster than those before the last major species extinction, which was the Paleocene-Eocene Thermal Maximum extinction, about 55m years ago. The IPSO scientists can tell that the current ocean acidification is the highest for 300m years from geological records.
They called for strong action by governments to limit carbon concentrations in the atmosphere to no more than 450 parts per million of carbon dioxide equivalent. That would require urgent and deep reductions in fossil fuel use.
No country in the world is properly tackling overfishing, the report found, and almost two thirds are failing badly. At least 70 per cent of the world's fish populations are over-exploited. Giving local communities more control over their fisheries, and favouring small-scale operators over large commercial vessels would help this, the report found. Subsidies that drive overcapacity in fishing fleets should also be eliminated, marine conservation zones set up and destructive fishing equipment should be banned. There should also be better governance of the areas of ocean beyond countries' national limits.
If you read between the lines, there's a clear and powerful message here.   It's that we have to come to grips with the reality that the oceans and our atmosphere are 'commons' and that we need to accept the responsibility for ourselves and to others for how we treat these commons.   If we want the oceans to remain capable of supporting marine and human life, we have no other choice.

What we all need to realize is that our species' willingness to salvage our oceans will demonstrate whether we have the collective will to resolve our global warming problem.   If we lose the oceans' integral role in our biosphere, we'll probably be too weakened, impoverished and destabilized to deal with everything else.

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