Land
The surface of the Earth is home to humankind as well as to most of the world's flora and fauna. We depend on it to supply nearly all our food and water as well as many of the materials which ensure our survival.

Ocean
Oceans cover far more of the Earth's surface than the land - in all about 71% - yet we know far less about them, even though their behaviour effects our weather and the atmosphere above us.

The Earth's atmosphere supplies us with the air we breathe and protects us from the radiance of the sun. Recent years have seen much discussion about the changes taking place in the atmosphere that surrounds the Earth.