The Spheres of Earth

The Four Spheres

Life on Earth is sustained by the interaction of four major systems:

1. Atmosphere (Air):

   • Contains Oxygen for respiration and Carbon Dioxide for photosynthesis.
   • Regulates temperature via the Greenhouse Effect.
   • Protects via the Ozone Layer.

2. Hydrosphere (Water):

   • Covers 70% of Earth.
   • Essential for all cellular processes, digestion, and temperature regulation in organisms.
   • Drives the water cycle (Rainfall).

3. Geosphere (Land/Soil):

   • Includes rocks, minerals, and soil.
   • Soil provides nutrients (Nitrogen, Potassium) for plants.
   • Geodiversity creates different habitats (mountains, valleys, plains).

4. Biosphere (Life):

   • The zone where the other three spheres interact to support life.
   • Includes everything from bacteria to blue whales.

The Importance of Balance

Earth functions like a giant team.

• Plants (Biosphere) take $CO_2$ from the Atmosphere and water from the Hydrosphere/Geosphere to make food.
• They release Oxygen back into the Atmosphere.
• Decomposers return nutrients to the Geosphere.

Even a small disruption, like cutting down forests, affects rainfall (Hydrosphere), soil quality (Geosphere), and air quality (Atmosphere).