Without volcanoes to build and fertilize land, Earth couldn't support life.

How wildlife adapts for survival to the seasonal shifts in the sun's intensity, from wood frogs that can freeze and thaw to Arctic wolves that thrive in the chilly darkness.

A look at how the planet's limited fresh water is distributed around the globe thanks to storms, and how animals manage in the driest habitats on Earth.

All marine life depends upon the constant motion of Earth's oceans.

A new dominant force now threatens our perfect planet. That force is us.