In the five-year period 2005-2009, Brazil dramatically reduced carbon emissions by about twenty-five percent and at the same time maintained a stable economic growth rate of 3.5% annually. This combination of economic growth and emissions reduction is unique in the world. It was driven by a dramatic reduction in deforestation in the Amazonian forest and the Cerrado Savannah. This shift empowered the sustainability social forces in Brazil to the point that in December 2009 Congress passed a very progressive law internalizing carbon constraints and promoting the transition to a low-carbon economy. The Article first analyzes the Brazilian position in the global carbon cycle and public policies since 2005, including the progressive shift in 2009 and the contradictory dynamic in 2010-2012. It then analyzes the potential for a transition to a low-carbon economy in Brazil and the impact on global climate governance.