The acute climate crisis, the failure of the Economics’ discipline to analyze and respond to the climate emergency, and the complex environmental and developmental challenges of the Global South constitute an interconnected triplet crisis. This chapter critically explores a wide set of contending discourses such as neoclassical Environmental Economics, Ecological Economics, Post-Growth, De-Growth Approaches as well as Marxist and Post-Colonial/Post-Development frameworks. This exploration underscores the methodological flaws as well as the North-Centric approach of the dominant neoclassical approach which has led to the exacerbation of the climate crisis and the under-recognition of the crisis of the Global South. While critical perspectives, such as Ecological Economics, Post-growth and De-growth, constitute responses to the analytical crisis of mainstream economics, they often offer a vague analysis of capitalism’s role in driving the climate crisis and overlook the complex challenges of the Global South under the hierarchical global divisions of economic and political power. By recognizing these limitations, the chapter contends that the interconnectedness of the triplet crisis is best understood by the frameworks of ecological colonialism and ecological imperialism. Despite their analytical differences, both frameworks provide crucial insights neglected by both mainstream economics and many of its critics and constitute a solid initial step for the decarbonization and decolonization of the economics discipline.