From WorldChanging: Costa Rica Aims to Become First "Carbon Neutral" Country.
As you can probably tell, my team is working a lot on Sun's energy and carbon strategies. While I don't know the details of Costa Rica's plans, it appears to be pretty direct. It probably helps to be 108th on the list of emitters, and to still have lots of forest to work with, but I'm sure there are still challenging aspects to it.
Good luck, Costa Rica! Let us know what works!