Today, the topic of climate change is a major part of daily life, yet 40 years ago it was virtually unheard of. Since then, Horizon have followed scientists as they have tried to unpick how the climate works and whether it is changing. Dr Helen Czerski delves into this unique archive to chart the transformation of a little-known theory into one of the greatest scientific undertakings in history. It has been a constantly surprising journey of discovery that has revolutionised our understanding of climate, and seen scientists face unprecedented controversy and criticism.

In a far cry from the steamy jungles of Rwanda or the icy waters of the Arctic, British naturalist Sir David Attenborough has donned a necktie and met with US president Barack Obama to discuss climate change and the future of the planet. The two met at the White House — a place the naturalist had never yet explored — on Sir David's 89th birthday in May to film the interview". It was the first time the respected wildlife filmmaker had met an American president and he seemed a little awed by the experience. Mr Obama, who grew up watching Sir David's programs, seemed equally thrilled. The president has the environment and climate change on his radar and is anxious to see progress made as his presidency comes to a close. He faces stiff opposition from Republicans in Congress on his plans to tackle climate change, but remains determined to make changes before leaving office. "I don't have much patience for anyone who denies that this challenge is real," he said. "We don't have time for a meeting of the Flat Earth Society." Sir David, who has been called "the godfather of natural history TV" by the BBC, brought to the meeting six decades dedicated to sharing the wonders of the natural world with television audiences. After initially being rejected for television because his teeth were deemed "too big", Sir David went on to make his Life on Earth television series, which has been watched by more than 500 million people worldwide. His name is now synonymous with nature, conservation and wildlife. During the television interview, the men discussed global warming, renewable energy and how children and young people hold the key to reversing the damage.

'What Makes Me?', explores the question of how the brain gives rise to our thoughts, emotions, our memories and personality. Philosophers and great thinkers have for millennia pondered the question of how physical stuff can give rise to mental processes. Last century, the new field of neuroscience joined the discussion, and Dr David Eagleman explains that to a neuroscientist, the answers to such questions lie in a deep understanding of the brain.

Filmmaker and artist Yann Arthus-Bertrand spent 3 years collecting real-life emotional stories from more than 2,000 women and men in 60 countries. Those emotions, those tears and smiles, those struggles and those laughs are the ones uniting us all. A combination of testimonies and exclusive aerial images, HUMAN is a unique documentary. This sensitive experience is an introspection into whom we are today as a community but also and most importantly as an individual. Through wars, inequalities, discriminations, HUMAN confronts us with the realities and the diversity of our human conditions. Beyond this darker side, testimonies show the empathy and the solidarities which we are capable of. All these contradictions are ours and HUMAN leads us to reflect about the future we wish to give to people and the planet today.

The final episode of the series visits the frontline of the conflict with the world's top predators, meeting the scientists fighting to save them. Crossing five continents and combining landmark natural history footage with real-life human drama, it checks the pulse of the earth's iconic animals, including lions, tigers, polar bears and blue whales. With three-quarters of the planet's carnivores now in decline, can people find ways to live with predators before they disappear forever?

In 1971, a group of friends sail into a nuclear test zone, and their protest captures the world's imagination. It was from these humble but courageous beginnings that the global organisation that we now know as Greenpeace was born. Chronicling the fascinating untold story behind the modern environmental movement, this gripping new film tells the story of eco-hero Robert Hunter and how he, alongside a group of like-minded and idealistic young friends in the '70s, would be instrumental in altering the way we now look at the world and our place within it.
Using never before seen archive that brings their extraordinary world to life, How To Change The World is the story of the pioneers who founded Greenpeace and defined the modern green movement.