The story of Tilikum, a captive killer whale that has taken the lives of several people , including a top killer whale trainer, underscores the consequences of keeping these powerful animals in captivity, the problems within the sea-park industry, the man's relationship to nature, and how little has been learned about these highly intelligent and sentient mammals.
Tilikum was captured in the northern Atlantic Ocean in 1983 and taken to Sealand of the Pacific, a now-shuttered park near Victoria, British Columbia. Former Sealand trainers interviewed in 'Blackfish' say the park’s female killer whales would aggressively gang up on Tilikum, particularly when they were confined in a 20-foot-by- 30-foot pool overnight.

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 over the course of a year. The exception is on the equator, where the duration of day and night remain the same throughout the year. Here, this guaranteed sunlight drives the great diversity of life in the tropical jungles.

Weather controls the distribution of freshwater on Earth. David Attenborough narrates how this uneven distribution has given rise to an incredible diversity of species and habits, from the driest desert to the lushest tropical rainforest. Featuring a colony of ants banding together into a raft every time its home in the Amazon floods, a rain frog that manages to eke out an existence in one of the world's driest habitats on Earth, and the last wild camels that survive the Gobi Desert's bitter winters by eating snow that blows in from Siberia.

Oceans are the largest ecosystem on earth, covering two thirds of our world’s surface and providing half the oxygen in our atmosphere. They are home to as much as 80 per cent of all life on earth, and nearly three billion people rely on them for their primary source of food.
But our planet’s oceans would be little more than stagnant wastelands, and life on planet earth would cease to exist, were it not for one simple factor: a global network of powerful ocean currents. Every drop of seawater on earth rides these currents, taking 1,000 years to complete a single circuit. Without the constant mixing of currents, tides and waves, our oceans would stop supporting life - and a healthy ocean is vital to a healthy planet.

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.

In the Taurus Mountains Simon stays with descendants of the original Turks, nomads known as Yoruks, whose lifestyle is under threat from the modern world and an increasingly religious government. They're not the only minority at odds with the authorities in Turkey; Simon sees first-hand the devastating effects of fighting in the country's Kurdish region. In an area where the government has detained foreign journalists, Simon gathers unique footage in the aftermath of a crackdown on Kurdish militants - the wholesale destruction of the historic centre of one of Turkey's oldest cities.
Away from the conflict in the south, Simon heads towards the Black Sea coast. He meets a wildlife conservationist protecting Turkey's population of brown bears, and villagers who still communicate over long distances using an ancient bird language. In the country's capital he meets a victim of President Erdogan's authoritarian purge of people accused of complicity in the failed coup against him.
Finally Simon's journey comes full circle when he returns to Istanbul - home to the new craze of 'Ottomania', a celebration of the vast empire that preceded modern Turkey. Simon visits the set of one of the world's most popular TV dramas - even getting a speaking role - based in the court of an Ottoman sultan