The Earth System

The ocean is a key component of the Earth System.

Our planet is one giant, finely balanced ecosystem. Life as we know it depends on a complex series of interactions between five interdependent systems: air (atmosphere); land (geosphere); ice cryosphere); living things (biosphere); water (hydrosphere). Collectively, these are known as the Earth System.

Despite the various names and territories we assign to the ocean it acts as a single entity – the global ocean. This holds 97% of the world’s water and is an essential component of the whole Earth System.

It is no exaggeration to say that the ocean is as critical to human survival as the air that we breathe – not least because it provides roughly one-half of the world’s oxygen, courtesy of the photosynthesis of microscopic marine plants. But it also plays a fundamental role in the Earth’s carbon cycle, nutrient cycle, water cycle and thermohaline cycle, all of which affect weather, climate and food chain patterns. Without them, our planet would not be habitable.