Ocean currents

Image credits: Unsplash/Jasper Wilde

INTRODUCTION Water transport is still one of the preferred modes especially when it comes to international trade. It is majorly carried via oceans and seas. To understand the effect of global warming on water transport, let us first understand how oceans help the transportation system. We have often heard the effect of climate change with respect to rising ocean and sea levels (threat to coastal cities), melting glaciers, floods, droughts, etc.

But there are other factors that we neglect while thinking of possible outcomes of global warming. EMERGENCE OF OCEAN CURRENTS

Ocean Currents are the result of what we have studied in our childhood – Land and Sea Breeze. These are the different heat-absorbing capacities of Land and Water respectively. Ocean currents are driven by a range of sources including the wind, tides, water density and rotation of the earth. They fall into two main categories- surface currents and deep ocean currents. The currents which are useful in water transportation are SURFACE CURRENTS. The wind is the major force behind ocean currents and the movement of the wind is due to atmospheric pressure. As the wind blows, it drags the top layer of water with it. The current moves in clockwise directions in the northern hemisphere and anti-clockwise in the southern hemisphere. This circular motion is due to the rotation of the earth.


The ocean currents are one of the prime reasons for water transport, which is stereotyped as slow means of transport and powered by diesel fuel. Though it is slow but is way cheaper than other means of long-distance transport. This is because ocean currents have set routes and when ships travel along their direction, they reach the destination comparatively quickly and efficiently when compared with the absence of ocean currents. Knowledge of surface ocean currents is essential in reducing the costs of shipping since travelling along the sea currents reduces fuel costs. In the wind-powered sailing-ship era, knowledge of wind patterns and ocean currents is even more essential.

Ocean currents

Image credits: Earth


With the already known importance of ocean currents on international trade, the change in their routes will give rise to new ocean routes. It will completely require new mapping of water transportation, extensive research and customization in floating vessels. High transportation charges can also be incurred if vessels have to float against the currents eventually leading to inflation which is the root cause of the threat to food security for the nations.

The Southern ocean, popularly known as the 5th ocean of the world, is the only ocean to be defined by an ocean current.

The current that differentiates it from the other 3 oceans bordering it is Antarctic Circumpolar Current (ACC). The climatic conditions including the wildlife(flora and fauna) were completely different in a circular area around Antarctica(The whole area inside the circumference of ACC) and therefore this delegation was given to it.

Ocean currents are an important abiotic factor that significantly influences food webs and the reproduction of marine organisms and the marine ecosystems that they inhabit. Many species with limited mobility are dependent on this “liquid wind” to bring food and nutrients to them and to distribute larvae and reproductive cells. Even fish and mammals living in the ocean may have their destinations and food supplies affected by currents. Marine wildlife is heavily dependent on the balance created by the ocean and is maintained by the ocean currents. The currents carry nutrients and food organisms feeding the plants and animals that depend on them. They also carry reproductive cells and ocean life to new places. The best example is sea turtles that lay eggs in the sand along the shores of the ocean.


Climate Change not only affects the earth directly but also indirectly. The warming of the earth is majorly absorbed by oceans. They absorb the heat, raising the temperature of their own. The rise in temperature of the oceans leads to melting of the glaciers and thus rising water level. Another very important aspect of the rising temperature of ocean water is the changes in the pressure levels which disrupt the breeze cycle, the root cause of ocean currents.

As the ocean accumulates more water by the melting of glaciers, the density changes because the dissolved minerals remain the same. This creates a problem by changing the floating capabilities of the vessel. Now as the water temperature rises, the air above the oceans becomes hot which changes the pressure level. Since the wind direction is determined by pressure levels, the ocean currents will change their direction in future as a result of Global warming This change will bring a transformation in transportation by means of waterways.

global warming and transportation

Image credits: Unsplash/william william


We can’t predict whether this will be a positive or a negative change but will definitely be a revolutionary one. When we foresee the results of climate change, we generally tend to forget the ocean currents while they deserve more attention than given.

Global warming is a serious issue and is a result of the damage done by the human species majorly. The damage can still be controlled but the irreversible damage is not very far away. Afforestation is the best medicine for Mother Earth.

Ocean currents may not seem very important for a common man in day-to-day life but are of utmost importance when it comes to transportation, maintaining water, and the seasonal cycles. When the ocean current in itself creates a completely new atmosphere resulting in the declaration of a new ocean, their disruption can do even what we cannot imagine as of now. There is no limitation to the damage taking place as a result of global warming.


Manan Chhabra

Guest Writer

B.A LLB (Hons.)

Dr. Ram Manohar Lohiya National Law University

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