Anna Hill visits a farm converting to organic at a time when the UK market is shrinking.
Alex James visits one of the BBC's Farmer of the Year nominees.
Chris Impey visits pig farmer and restaurant owner Sally Jackson in north Lincolnshire.
Adam Henson meets the third BBC Farmer of the Year finalist, Adrian Dolby, in Oxfordshire.
Bicycles made from wood? Meet visionary bike designers Paul Harder Cohen and Mette Walsted
A look at the new green fuels and how the technology can best be utilised.
China needs more water urgently. Isabel Hilton examines the nation's options.
Why dismantle a dam that produces low-carbon electricity? Peter Gibbs investigates.
Tom Heap asks if a new breed of electric car may finally bring them to the mainstream.
Is it time to buy an electric car? Peter Gibbs takes the plunge.
Adam Henson meets the first of the contenders for this year's BBC Farmer of the Year award
Sybil Ruscoe is at a farm growing maize to produce electricity by anaerobic digestion.
Judging continues in the Outstanding Farmer of the Year category.
Tom Heap investigates the key arguments for and against the use of biofuels.
Tom Heap finds out how Iceland could solve Britain's energy crisis.
Helen Mark finds out about Canon Frome, an eco-community in Ledbury.
Gareth Mitchell asks what happened to hydrogen cars.
Inspiring the inventors who will lead the way in the fight against global warming.
Nick Davies visits Source Farm in Jamaica, where organic farming is part of a revolution.
Roni is 33 years old. She has never learned to ride a bike. Is it too late?
Enormous new dams threaten life on one of south east Asia's most vital rivers.
To have them or not to have them, that is the question.
Tom Heap finds out how communities large and small can produce their own electricity.
Alice Roberts discovers the potential savings available by harnessing the power of sewage.
Could the military lead us into a green future? Tom Heap investigates.
Could high-rise farming be the solution to feeding our cities or is it a utopian fantasy?
Will the promise of energy from the oceans become reality? Tom Heap reports.
Gaia Vince asks if we can ever run our vehicles on biofuels from algae or bacteria.