how does the oceanic conveyor belt affects the earths temperature.? can this be the key for global warming

The Great Ocean Conveyor Belt circulates the oceans water around the planet.  As it does this,  the water currents  carry with them  heat and nutrients that keep our planets ecosystem healthy, and they keep weather conditions consistent in every region.  Winds help with the movement of this undercurrent of water.  Now, with global warming becoming a factor in how our earth and its waters are warmed; there are big changes taking place. How the sun beats down on the earth, differently in different locations, is what keeps the conveyor belt of ocean water moving.  The waters at the equator are quite warm and as they move to higher latitudes, they begin to cool and heat rises in these areas to warm the climates. This transference of warm water currents  and cold water currents is what makes the conveyor belt keep moving.  The dense colder waters sink to the ocean floors.  Global warming is changing the process and is creating a huge meltdown of the areas that have always been cold;  like the Polar Regions of Greenland, and Ice Land.  Some ecosystems are beginning to die.  If we are to keep a healthy planet, we must stop this warming and reverse the effects that have damaged the oceans delicate balance of sea life.