Something weird seems to be happening to our weather - it appears to be getting more extreme. In the past few years we have shivered through two record-breaking cold winters and parts of the country have experienced intense droughts and torrential floods. It is a pattern that appears to be playing out across the globe. Hurricane chasers are recording bigger storms and in Texas, record-breaking rain has been followed by record-breaking drought. Horizon follows the scientists who are trying to understand what's been happening to our weather and investigates if these extremes are a taste of what is to come.
Surviving the bone-chilling cold, deadly blizzards and darkness of an Alaskan winter takes courage, cunning and remarkable endurance. In the raw beauty of windswept mountain peaks, icy tundra and snowbound forests, this is the story of the tough and resourceful characters that face up to the ultimate challenges of this untameable land.
Volcanoes have a fearsome reputation. In reality, they are the most important force in the creation of the planet as we know it today. Iain abseils into a lava lake and cave dives in a cenote to show how the heat that fuels volcanoes also drives some of the most fundamental processes on the planet.
Off Australia's northeast coast lies a wonder of the world, a living structure so big it can be seen from space, more intricate and complex than any city, and so diverse it hosts a third of all fish species in Australia. The Great Barrier Reef as we know it -- 8,000 years old and home to thousands of marine species -- is dying in our lifetime.