Can bio fuels provide a viable alternative energy source?
BBC World Service
Fierce debate as the latest world population figures are released
The controversy that has engulfed New York and the entire US.
The BBC's Rayhan Demytrie explores the world of politics and drugs in Kyrgyzstan
BBC World Service tracks East Londoners who live in the shadow of the 2012 Olympic Park.
Listen to Mandela's thoughts on the night of his release from Robben Island
25/40 Brett Westwood reports on migrating birds in the skies over London.
BBC Radio 4
Is the heart more than just a pump?
Why should we want more foundation hospitals when so many are in financial trouble?
Examining the link between the brain and consciousness