1. Global Change
Four Spheres

2. Four Spheres Lithosphere Hydrosphere Biosphere Atmosphere
Earth is divided into 4 spheres:
Lithosphere
Hydrosphere
Biosphere
Atmosphere

3. Lithosphere This is the solid, rocky crust covering the entire planet.
Is the Earth’s crust and the upper layer of semi-molten mantle
Broken into large pieces called tectonic plates
Consists of rocks, soil, sand, minerals, coal, oil and natural gas

4. Hydrosphere Composed of all the water on or near the Earth. Includes;
Earth’s oceans
Lakes
rivers and creeks
Moisture in the air
97% of the earths water is in the ocean.
3% is fresh water, 75% of this is solid in ice sheets.

5. Biosphere This is composed of all living organisms.
Plants, animals, and one-celled organisms
Most life is found from 3m below the ground to thirty meters above it and in the top 200m of the oceans and seas.

6. Atmosphere 1. Troposphere 2. Stratosphere 3. Mesosphere
This is the body of air which surrounds our planet
Consists of four layers:
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere (including ionosphere)
Composition
78% Nitrogen
21% Oxygen
1% Trace Gases (mainly Argon)