Did you know that the ocean plays a number of very important roles in regulating our climate? From helping to keep our planet warm, to influencing precipitation patterns around the world, to playing a critical role in the global carbon cycle, the Earth’s climate just wouldn’t be the same without our global ocean.

The Ocean warms the planet

Most of the sun’s radiation that hits the Earth is absorbed by the ocean (98% of it, to be exact), especially in the tropical regions of our planet [1]. The Earth’s atmosphere also helps to retain this solar heat that would otherwise be lost into space after the sun goes down.

The ocean stores radiation from the sun and distributes it globally from the tropics to the polar regions by winds and ocean currents.

The ocean influences precipitation patterns

As ocean water is heated by the sun, it evaporates and is transformed into water vapor that increases the temperature and humidity of the air, forming rain and storms. This precipitation is carried by winds to large distances around the world.

The ocean’s role in producing precipitation is so important that nearly all rain that falls over the Earth’s land originates from the ocean.

Heat absorption and ocean evaporation are particularly high in the tropics, which receive more than 15 inches (3 m) of rain per year and approximately 8mm of rain per day [1].

Global weather patterns are controlled by ocean currents

Weather patterns are primarily controlled by ocean currents, which are influenced by surface winds, temperature, salinity, the Earth’s rotation, and ocean tides. Ocean currents generally flow clockwise in the Northern Hemisphere and counterclockwise in the southern Hemisphere.

Ocean currents bring warm water and rain from the equator to the poles and cold water from the poles toward the equator. These ocean currents help to counteract the high levels of solar radiation that the Earth’s equator receive.

Without these currents, it would be much hotter at the equator, much colder at the poles, and our planet’s land would be much less livable [2].

Photosynthetic organisms in the ocean influence the global climate

About half of the global carbon cycle is managed by photosynthetic organisms that live in the ocean such as phytoplankton, that produce oxygen and influence the levels of greenhouse gases (like carbon dioxide and methane) that are present in the ocean and in the atmosphere.

The level of greenhouse gases in the atmosphere influences global temperatures and weather patterns because these gases absorb solar heat so efficiently.

While much of the information on climate change that we are exposed to focuses heavily on CO₂ in the atmosphere, almost half of the carbon dioxide that is being produced by the burning of fossil fuels has been absorbed by the ocean [1].

The ocean’s heat storing ability

The temperatures in the atmosphere are influenced and slowed down by the ocean’s capacity to store heat. Because of this ability, the ocean has stored 18 times more global warming heat than what has been stored in the atmosphere since the 1950s [1].

The ocean influences regional climate

In addition to affecting climate on a global scale, the ocean also influences the climate of various regions around the world. The difference in temperature between the land in the middle of a continent and the surrounding ocean drives the development of monsoons.

In the winter, the much colder air over a continent flows outward toward the ocean, and in the summer, the much hotter air over a continent draws moist air inland, bringing forth summer rains.

Cities located along coastlines also benefit from ocean breezes, a result of the difference in temperature between land and sea, where the land is cooler at night and warmer during the day [1].

Everything is connected

Our planet has an interrelated climate system, where the ocean, atmosphere, and the land all interact with each other, influencing the climate.

Whether it is rain that heats the atmosphere, warm air that creates wind, or wind that drives ocean currents and determines the distribution of phytoplankton, changes in one area of the global climate system could undoubtedly alter things in the other areas as well.

With an understanding of this interconnection, it is important to realize the influences that our choices might make on these systems, such as humanity’s choice to continue to burn fossil fuels or to transition to a clean energy future that will safeguard our planet’s climate for future generations.