The creation of an emissions trading system in Mexico as response to international policy on climate change forces the government and corporations to create new activities and responsibilities to address this issue. It is also important to know who will be the decision-maker and who is in charge of the institutional work (representation and negotiation). The main objective of this chapter is to point out who the stakeholders involved in the design, implementation, evaluation and transparency of the system are, or should be, according to the national regulatory framework and international summons. We shall also analyze the mechanics and information provided by the system and how it helps to make environmental policy, which helps to reduce emissions. Finally, we will also analyze whether it also helps to establish strategic alliances and international agreements toward common objectives and priorities. The chapter approaches the topic based on capacity development theory, which focuses on improving governance among different levels and stakeholders: government, companies, civil organizations, and scientists. We emphasize the potential of training spaces as a place for transformation and developing a learning framework whose own relevance relies on the focus of emergent strategies, which ensure the environmental integrity and conditions for the country’s competence in the international context. This chapter contributes to existing literature about the understanding of executing such a system, the stakeholders involved at the national level, and their potential to create international networks.