Chris Packham tells the miraculous story of how plant life turned Earth from a barren rock into a vibrant green world - a four-billion year saga of extraordinary highs and lows that almost wiped out all life on the planet. Beginning as a water world without land masses, a giant asteroid bombardment triggered Earth's plate tectonics, leading to huge fungi, soil and giant swamp forests. But the early plants locked so much carbon dioxide that global temperatures suddenly plunged.

When Earth first formed from clouds of dust and gas 4.6 billion years ago, it was - like so many other lifeless worlds in the universe - devoid of an atmosphere, an inhospitable rock floating in the black void of space. But as the young planet is pummelled by asteroids, a period of extraordinary upheaval begins.

Today, Earth is a human world, home to eight billion people and counting. Humans now have a greater effect in shaping Earth’s surface than many natural processes. Chris Packham explores how dramatic twists in Earth’s story enabled humans to go from being part of nature to controlling it and what can be learnt from this epic tale before it’s too late.