The last episode examines the fragile interdependence that exists between forests' wide variety of residents, including bald eagles, hunting dogs and Siberian tigers.
Over half of all the world's trees, evergreen and deciduous, stand in great assemblies. For many of us, they are places of mystery and darkness. They are key to our climate, and home to countless unique species. The boreal forest contains 750 billion trees, and it stores over 40 percent of the world's carbon, making it a vital element in the fight against climate change. In the past, we have destroyed them without hesitation. Yet, forests do have an astonishing ability to recover. If we choose to give forests time and space, they could reclothe the earth with much of the rich and varied communities of animals and plants of which we have, so recently, robbed it. A future with more forests is key to the resilience of our planet.

This remarkable science-history series investigates the blistering pace of human endeavour in space exploration, computing, energy, resources, Earth science and our understanding of the evolution of life itself. Across the last 50 years, humans have set a blistering pace and scientific discovery. We've crossed the boundaries of our solar system, made machines that can learn harnessed the power of the sun and built life from scratch. It's a period like no other in history, where human endeavour is changing everything: this is The Great Acceleration. As we race toward the future, we must examine the journey.
In the first episode, Dr Shalin Naik explores the ambitious space shuttle mission that began in the '70s plus the future colonization of Mars. Over the past 50 years, space has become central to everything, from communications to entertainment to climate modelling. And as private enterprise enters space exploration, our understanding of the universe will only continue to expand. We will know if we can survive on other objects - the moon, maybe Mars, maybe even some of the moons of Jupiter and Saturn. Deep space is the last and infinite frontier. That's what we do as human beings. We explore, we learn, we make discoveries, from the moment we're born to the moment we die.

Over the last years, the world has experienced an energy revolution, driven by an urgent need to green the grid and save life on Earth as we know it. 50 years ago, a devastating oil crisis kicked off an energy revolution. The world set course to cut the costly habit of burning fossil fuels. With the urgent new threat of a changing climate, the drive to unleash the power of the sun, earth and wind has accelerated into a race for humanity's survival. Change is taken place but, is it happening fast enough to secure our future? Technologies are right here, right now, and they will enable the transition to 100% renewables, because winning the energy race means a win for the entire world.

Across the world, rising demands for food, water and materials have pushed resources to the limit. Many parts of the world have major challenges over fresh water. A lot of soils have a lot of residual pesticides and herbicides. At the same time waste is piling higher. All this demands a new wave of innovation. The challenge is to make more of the things we need without the environmental cost.

The Blue Marble is an image of Earth taken on 1972, from a distance of about 18,000 miles from the planet's surface. It was taken by the crew of the Apollo 17 spacecraft on its way to the Moon. Before it was photographed from space, our perspective of Earth was fragmented and disconnected. Recent discoveries have revealed a dynamic and rapidly changing planet, above the crust and below.

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.