In the space of a few years, the small Central American nation of Costa Rica has become a global laboratory for decarbonization. Costa Rica is the only tropical country in the world that has managed to reverse the deforestation process: forests now cover more than half of its surface. It is also one of the few countries that gets almost all of its electricity (99 percent) from renewable sources. Costa Rica’s bold and inspiring example reflects poorly on the major world powers, which have considerably more resources available to achieve their climate goals. Our regional correspondents Laurence Cuvillier and Matthieu Comin report.