Wednesday, February 27, 2008

Dying seas and global warming

The journal Science published a paper this week about the increase and spread of Dead Zones in the world oceans. These Dead Zones are created when large amounts of nutrients decompose  and use up all of the oxygen in the water causing mass deaths (literally suffocation) of marine species. There are various causes for this, but changes in wind, temperature and current regimes are increasingly thought to play an important role. 

Interestingly the paper concludes that these dead zones may be a symptom of global warming. Description of thousands of dead crabs and other crustaceans found at the bottom of the ocean in one of these dead zones brings to mind the severe coral bleaching event which occurred in the Seychelles and elsewhere following the one month extreme warming of parts of the Indian Ocean in 1998. What was left behind was a mass grave of dead corals and loss of livelihood to islanders and coastal people. In fact in  a statement by the US Department of State in 1999 the following important conclusion was made:

"These events (i.e. the coral bleaching of 1998)cannot be accounted for by localized stressors or natural variability alone. Nor can El Niño by itself explain the patterns observed worldwide. Rather, the impact of these factors was likely accentuated by an underlying global cause. Thus the geographic extent, increasing frequency, and regional severity of mass bleaching events are likely a consequence of a steadily rising baseline of marine temperatures, driven by anthropogenic global warming."

The number of dead sea zones have effectively doubled per decade, since scientists have started to document them. Notable areas include parts of the US coastline, South African and Namibian coastline and other parts of the world. These dead zones further threaten the livelihood of people dependent upon the coast to survive.

We once believed that the oceans could take all of the worlds waste, we were soon proved wrong. We are also wrong about the atmosphere, it cannot take all of our waste, we need to reduce emissions, we need to promote renewables so that there can be more research and the price can go down and both China and India will be able to afford energy technologies. That is the message I have for the skeptics, the signal for immediate action on climate change can be found in the oceans. Islanders have learnt to live, respect and protect the oceans, the continental world needs to understand how important the ocean is to them as well.