Green Economy is designed to increase global "green" research, to motivate political "green" decisions, and to support "green" investments. Specifically, this paper offers three dimensions of green economy: economic perspective, political perspective, and ethical perspective to illustrate a sustainable approach of the green economy. There aren't perfect solutions to solve a problem, so does implementing sustainability as a tool to solve environmental problems. However, there are still many economists looking for a perfect "free lunch" in sustainability, which they are overly optimistic about their sustainable calculations, but end up shooting themselves in the foot. Thus, the answer to the development of the green economy should be within the duality of "benefits and costs", "conflicts", and "opportunities and challenges". Overall, the paper is constructed in a format of exogenous dualities that consists of "benefits and costs", "conflicts" and "opportunities and challenges".