65 Million Years ago, an asteroid impact caused a cascade of catastrophes that led to the downfall of the dinosaurs, but what would happen if the same size space rock struck near the same spot again?
No season brings more surprises than an Alaskan summer. It lures hummingbirds up from the tropics, exposes deserts in the Arctic and relies on parachuting firefighters to tackle forest fires in its vast wilderness. Summer is a narrow window of plenty, when the land is bathed in 24-hour sunlight - but in this land of extremes, you can have too much of a good thing.
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.
We are all seeing rather less of the Sun. Scientists looking at five decades of sunlight measurements have reached the disturbing conclusion that the amount of solar energy reaching the Earth's surface has been gradually falling. Paradoxically, the decline in sunlight may mean that global warming is a far greater threat to society than previously thought.
Earth's current problems and how to help in conservation efforts
A look at one of the most exclusive holiday destinations in the world - Necker Island. This reveals how the rich take a holiday, and what it's like for the staff who serve them.
We are living in exceptional times. Scientists tell us that we have 10 years to change the way we live, avert the depletion of natural resources and the catastrophic evolution of the Earth's climate.
93m • 2009