Please turn on JavaScript. Media requires JavaScript to play.
Costa Rica has pledged to go carbon neutral by 2021, the only developing country to set such a target.
New Zealand, Iceland and Norway have also signed an agreement to cut their carbon emissions to zero.
Claire Marshall reports from Costa Rica.
What are these?
E-mail this to a friend
One-Minute World News 
Bookmark with:
What are these?
E-mail this to a friend