The Great Oceanic Life Preserver

May 4, 2012 6:26 pm

There is great debate, as is fashionable, over our climate and the perhaps irreparable damage we, as the gatekeepers of this amazing planet are causing. In these times of carbon fuel fixation there is one great factor that is overlooked by everyday people going about their everyday business. The factor known simply as the great ocean conveyor. An unimaginable submarine engine that keeps all of the facets of our existence in….well existence. This is true not only for the human race but for all life on Earth, air, land and sea. It is an engine which needs only heat and the breath of the wind to drive it and yet it is so powerful that it is capable of controlling not only the air that we breathe but also the temperatures we rely on to survive.

The journey begins in the North Atlantic Ocean where, as it ventures upwards from the equator pushed gently by surface winds, a combination of evaporation, causing the salinity to increase, and cooling, causing it to densify and so gradually sink to the cold dark depths of the Atlantic. This water is now known as North Atlantic Deep Water. Here it begins its slow journey south, closely passing the continental shelves of North and South America, remaining cold and deep and gradually turning eastwards towards the Antarctic. As the newly named Antarctic Circumpolar Water navigates the South Polar region, it turns north where it joins the oceanic basins of  the mighty Pacific and Indian Oceans, slowly warming and mixing with these ocean waters, reducing in salinity and rising ever so gently to the surface. This is not a hurriedly completed exercise; the waters rise at a rate of only a few meters per year, giving us an insight into the sheer scale of this epic journey. As the waters reach the surface, they traverse the many passages of the Indonesian islands and on to the Indian Ocean, continuing with the assistance of the wind around the tip of South Africa eventually rejoining the Atlantic and the trip north to begin the loop again. This whole trip can take an estimated 1500 to 2000 years to complete. Although the description of the mechanics of the conveyor is much simplified here, it is no less impressive.

This conveyor plays an essential role in distributing the sun’s warmth around our world and the much maligned climate change theory has the potential to bring this engine to a halt. It has happened before, and it can happen again. One recent example of this stall in our life support system happened as recently as 600 years ago in an event that came to be known as ” The Little Ice Age”, famous for giving enterprising Londoners the opportunity to hold ice markets on the frozen waters of the Thames, but this pales in comparison to an event that occurred much, much earlier in our planet’s history. An event that almost ended the existence of every living thing on our home planet. 300 million years or so ago, the engine cut. According to fossil deposits, found around the globe, this aided the decimation of 80 to 95% of all marine life. Reefs didn’t begin to recover for over 10 million years and clearly was a staggering loss of species and organisms essential to the survival of not only marine animals, but also to land and airborne creatures too.

The cause of this stutter in the ocean conveyor is highly debatable, but the evidence of the enormous amount of sea life fossils deposited on the ocean floor during this period is irrefutable. There are a number of reasons that the deep ocean currents may come to a standstill. One of these is the effect of the warming of our planet. Ice caps in the north and south of our home melt and the huge influx of fresh water can dilute the sea water and reduce salinity, taking away the waters ability to sink into the depths and push the foregoing water south. The current comes to a stop and the oceans can become stagnant and lifeless, our cold corners of the planet not close enough to the equator to benefit from the full strength of the Sun’s rays would freeze under a blanket of ice. Another effect of the absence of the deep water conveyor belt could be the rapidly changing Co2 levels that we as a species are producing. The levels we currently add to our atmosphere are unprecedented. The ability of nature to change and adapt to new circumstances and environmental conditions is truly amazing, but this takes time through evolution. The rate of change is currently unmanagable, even for the great mother nature. The rising levels of Co2 are such that the acidity of the oceans will rise, which in turn can cause an effect known as anoxia, essentially the absence of oxygen.

If the addition of Co2 into our atmosphere continues at the current rate, the effects of which may take a century or more to become apparent, then the Earth could be heading for a mass extinction it may never recover from. There is actually no single group of people or industrialists that are to blame. We all are, though few people seem able to admit this. Power station operators blame forresters, forresters blame car users, car users blame fishermen, and so on. The fact is that we can all do a little something to help. Take a look at your lifestyle, and see if maybe you yourself can do a little something to help yourself and others, in this generation, and in the generations to follow.


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