Oceans – which cover the majority of the planet – affect Earth’s climate by being an excellent heat sink and distributor. On a daily basis and from around the clock movement, the Earth’s oceans are responsible for most large weather related events and control not only the course of the climate of today, but the one of tomorrow as well. This control is one of the main influences on planetary climate direction, but can also be altered by various circumstances.
The three states of water on the planet each have their own role in regards to the heating of the planet by the sun. The state with the countering effect to heating is the solid state. Ice and snow on the surface of land and on the oceans will reflect heat energy from the sun and minimize the amount absorbed. Ice crystals that make up clouds can also reflect light and cool areas of the land and water below. The most abundant state, the liquid state, absorbs heat from sunlight and stores it. This heat plays a vital role in localized climates and balancing temperatures across the globe, but can also accelerate the melting of sea ice. The gas state, water vapor, can cool the surface of the ocean slightly as the liquid water evaporates, taking some of the heat with it. Water vapor can absorb heat on its own as a gas, and contributes to global warming along with carbon dioxide and methane.
Heat distribution in the oceans is due to giant flowing ‘rivers’ within them that are known as currents. Currents are formed by the rising warm waters around the equator, and the sinking colder waters near the poles. This rising and sinking water flows in a continuous loop, delivering cold waters to the warm, and warm to the cold, keeping waters more regulated than if they were stagnate. One such current, known as the Gulf Stream, is the primary reason as to why Europe remains as temperate though it is at the same latitude as Canada, which is much colder in comparison. The cold water from the returning stream flows down the coast of Newfoundland, which helps explain why it remains cold.
Separate from currents, hurricanes, typhoons, and monsoons are all large storm systems that form over warmer oceanic waters. These storms are responsible for distributing a great deal of water back into areas that would not see as much water on a yearly basis without these large storms, thus re-supplying the water tables. In addition to water, heat and warmer temperatures carried with these storms help to warm up areas that are geographically cooler or entering the fall or winter seasons.
Although the main concern of the ocean and climate now is the contribution towards global warming (as sea levels rise, absorb more heat, and melt more ice, thus accelerating the process), it can also be influenced by countering events. Most of these scenarios involve asteroids that impact the oceans or land with enough force to kick up substantial quantities of dust or water vapor, inducing a cooling effect on the world. At this time the oceans would gradually cool and start to freeze at the poles at a constant rate, until the clouds cleared, though likely introducing a new Ice Age, however small. In this way the ocean would have contributed to the cooling by maintaining the new ice layers, and would only melt away after sufficient quantities of warmth was absorbed.