The aim of the article looks through a comparative perspective, to establish the analytical categories of political ecology and post-development, to determine which are the critical thinking conditions that the governments of Brazil, Colombia and Ecuador (countries that are part of the regional process UNASUR), presented to perform various processes of exploitation and impact on ecosystems, and thus the social development of urban and rural areas that are conditioned on the way to understand this subject, which currently leads the interest of the international community.The first part provides the theoretical and methodological considerations; while the second focuses on the characteristics of exploitation of natural resources which are in force in South America, where they always have been justified traditional economic policies, to maintain stable and permanent macroeconomic indices. This being a very critical situation for the geoenvironmental stability, not only in the region but throughout the world. The results and conclusions will provide to the reader the structure and contemporary theoretical dialogue,arising from the objective. In particular, the show of the needed theoretical change to meet the environmental challenges produced by the system.