A new force threatens our perfect planet. In the past, five mass extinction events were caused by cataclysmic volcanic eruptions. It was not the lava or ash that wiped out life, but an invisible gas released by volcanoes: carbon dioxide. Almost every part of modern life depends on energy created by burning fossil fuels, and this produces CO2 in huge amounts. Humans are changing our planet so rapidly, it’s affecting earth’s life support systems: our weather, our oceans and the living world. The greatest change to be made is in how we create energy, and the planet is brimming with natural power that can help us do just that. It’s these forces of nature - the wind, the sun, waves and geothermal energy - that hold the key to our future.
Through compelling animal-led stories and expert interviews, we discover how CO2 is destabilising our planet. We meet rescued orphaned elephants in Kenya, victims of ever worsening droughts, and join ocean patrols off the coast of Gabon fighting to save endangered sharks. In the Amazon, we witness wildlife teams saving animals in the shrinking forests, and in San Diego we enter a cryogenic zoo preserving the DNA of endangered species before they become extinct.

Astronomers make an extraordinary discovery out in deep space when they uncover a cosmic mega-structure that's one billion light-years long. Now, investigators race to decode the hidden forces that shape the most massive and mysterious structure known in the Universe.
We dive into this space great wall's fiery birth and hunt for the weird cosmic glue that holds it together to reveal how this megastructure rewrites our understanding of the universe on an epic scale.

Garrett McNamara and his team return to Nazaré for another season of surfing. The team struggles through a number of accidents and challenges but eventually develop a set of safety procedures that enable them to surf Nazare's wave with less chance of injury or death. The struggles pay off when McNamara catches a nearly 80 foot tall wave that catapults him to international fame and makes him the holder of the world record for largest wave surfed.

After losing his drive to continue surfing at Nazaré, Garrett McNamara decides to return to competitive surfing at other big-wave sites. In order to compete in a tournament at California's Mavericks surf site, he must surf there regularly, something that he has done many times in the past. McNamara returns to Mavericks only to suffer a horrific injury on a wave he should have aced.

Garrett McNamara recovers from the injuries he sustained at Mavericks and begins training to return to Nazaré for another season. While surfing at Indonesia's G-Land site, Garrett suffers more injuries that threaten to take him off the waves permanently. Meanwhile, a friend of Garretts catches an 80-foot wave at Nazaré, taking the world record from McNamara. McNamara resolves to continue his hunt for a 100-foot wave.

As dozens of top surfers from across the world arrive in Nazaré to train and prepare for a major big-wave competition, Garret McNamara continues to struggle with his physical injuries and mental preparedness. He knows he is not ready to surf in the competition but seeing the other surfers makes him consider competing anyway. Garrett also has misgivings about the state of safety plans at the competition, and tries to convince the organizers to beef up their plans.