Changing ocean currents and consequences

Everyone knows that the sun is major source of energy on our planet. The plants harness this solar energy for photosynthesis to produce food, which is then consumed by consumer including human being and support the life at first place. But other than sun, water is no exception and it is no less important than former. In solar system, every planet receives sunlight but it is water that make our Earth unique. It also essential building block of photosynthesis, plant cells and animal cells. Above all water maintain the temperature of our planet and makes it a place to live. It covers 97% of Earth surface. Almost 71% of water forms the oceans. These oceans are not distinguished by discrete boundaries and water flows freely without any obstruction and collectively form a giant World Ocean. Albeit this water is not drinkable, it plays a key role in maintaining the temperature equilibrium of our planet. To carry out this process, water form thermohaline cycle or ocean conveyor belts. The ocean on tropical zone faces the direct rays of sunlight which warms the water. The volume of water increases with the rise in temperature. The density of water has inverse relation with volume so on tropical belt water density is lower than polar region due to higher temperature. The higher denser water rises up whereas lower denser water sink down. The vacuum created by denser water is filled by water with more temperature. When this water reaches the colder part of Earth, it releases its heat into surrounding atmosphere. This is how these ocean currents maintain the temperature in colder region and make the places inhabitable. Apart from temperature, the concentration of salt in ocean also contribute in this cycle by varying its density. For the past couple of decades, due to uncontrolled use of fossil fuels and carbon emission, the average global temperature has enhanced above the optimum level and give rise the phenomenon of global warming. Global warming has put massive pressure on ice caps and water resources. The melt water in polar regions makes its way to ocean and disturbing the natural cycle of ocean currents. This pattern changing thermohaline cycle has deep impacts on global weather pattern and climate. If these trends continues at the same level, the threats of global extinctions, human migrations and war on water resources are not far away.