Humans are changing our planet so rapidly, it’s affecting earth’s life support systems: our weather, our oceans and the living world.

There are not five separate oceans, but one. Its waters linked by powerful forces that keep them on the move. This constant mixing is vital for the health of oceans and marine life.

A look at how without volcanoes, there would be no life on Earth. Although destructive, magma from the planet’s molten core builds land, and mineral-rich ash from eruptions fertilises the surface.

From the frozen poles to the searing deserts, this episode shows how animals have come up with strategies to survive the uneven amounts of sunlight that fall on our planet.

Weather controls the distribution of freshwater around our planet. In turn, shapes the lives of animals across the globe, rising to an incredible diversity of species and habitats.