The digital era gives rise to unprecedented opportunity to exploit, and be exploited. Troves of child pornography are available at the click of a mouse. Who are these children - and who profits from their abuse? While facilitating the darker side of our impulses, technology is also being touted as a cure to rehabilitate predators. In this episode meet the children who are forced to perform sex acts on camera; people who use the same technology to protect kids and nab the perpetrators; plus, a pedophile who reveals the roots of his addiction.

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.

The Culture High is the riveting story that tears into the very fibre of modern day marijuana prohibition to reveal the truth behind the arguments and motives governing both those who support and those who oppose the existing pot laws. With budgets to fight the war reaching billions and arrests for simple possession skyrocketing to nearly a million annually, the debate over marijuana's legality has reached epic proportions. "The Culture High raises the stakes with some of today's biggest names, unprecedented access to footage previously unobtainable, and incredibly moving testimonials from both sides of the spectrum. Top celebrities, former undercover agents, university professors and a slew of unforgettable characters from all points of view come together for an amusing yet insightful portrait of cannabis prohibition and the grasp it has on society as a whole. "The Culture High" will strip search the oddity of human nature and dare to ask the question: What exactly is going on here?

A dynamic journey behind the scenes of the next step in the evolution of telescopes: NASA's James Webb Space Telescope. A new generation has been inspired to design and build this massive instrument, which is 100 times more powerful than the Hubble Space Telescope and will be a veritable time machine, capable of looking back on the origins of our universe and identifying signatures of potential life on planets far outside our solar system". With unprecedented access to the people and technologies that power its creation, including astrophysicists, engineers at Northrop Grumman, and personnel from NASA'S Goddard Space Flight Center and the Space Telescope Science Institute, the operations center for Hubble and Webb, Telescope spotlights the high-stakes mission of building this massive new scientific instrument. The film is a comprehensive look at the dynamic history of 400 years of telescopes starting with Galileo in 1609. The Webb is the next great telescope in society's ongoing mission to see farther into the universe and answer fundamental questions that have haunted mankind from the beginning of time. Directed by Oscar nominated filmmaker Nathaniel Kahn

Set against the chaotic backdrop of recent events in the Middle East, Nadav Schirman's THE GREEN PRINCE retraces the details of a highly unprecedented partnership that developed between sworn enemies. In the style of a tense psychological thriller, this extraordinary documentary recounts the true story of the son of a Hamas leader who emerged as one of Israel's prized informants, and the Shin Bet agent who risked his career to protect him.

An intimate and heart-warming look at the man behind the legend - as we've never seen Ali before. Told through exclusive, unprecedented access to Ali's personal archive of 'audio journals' combined with touching interviews and testimonials from his inner circle of family and friends, including his daughters, son, brother and former wife, plus legends of the boxing community including Mike Tyson, George Foreman and Gene Kilroy