More than 100 heads of state and 50,000 delegates - business players and activists - have been in Rio for the Rio+20 summit, hoping for a new agreement to safeguard the future of the planet. <br /><br />It is called Rio+20 because 20 years ago, the first Earth Summit, creating the first international agreements on climate change, was held in the Brazilian city.<br /><br />But what has happened since then?
