Central and south America and the Caribbean countries share energy and climate features that are quite different from the rest of the world, including a highly renewable energy mix and very high renewable energy potentials, along with high deforestation and degradation rates which call for regional answers to regional issues. This paper assesses the impact of national contributions to the United Nations Framework Convention on Climate Change using an energy prospective model from the MarkAl/TIMES family. This approach enables a bottom-up comparison between past pledges (Nationally Appropriate Mitigation Actions) and the Nationally Determined Contributions (NDCs) agreed on at COP21. Long-term economic optimization leads to decarbonizing the power sector even in the absence of climate constraints. Stringent climate policies as modeled here achieve emission reductions of 40% below the current baseline by 2050. NDCs produce stronger emission reductions than NAMAs at regional scale; however, the first contributor to emission reductions in absolute terms in Latin America is the Agriculture, Forestry and Other Land-Use (AFOLU) sector, not energy.