The present paper describes a comprehensive review on the current state of art on the interactions of the green computing and computational intelligence areas and their applications to real world-problems. Green computing can be viewed as the responsible use of computers and their corresponding resources for achieving environmental and ecological goals. On the other hand, computational intelligence is an area consisting of methods and models for building intelligent systems, such as neural network models, fuzzy logic systems and genetic algorithms. The interaction of the two areas could produce intelligent systems that can achieve environmentally responsible and eco-friendly applications, which can help really achieve the main goals of green computing. The present review summarizes the most relevant existing works on these areas, as well as the current applications that have been done to the moment. In addition, an analysis on the trends of current existing works and a discussion of possible research trends are also offered. The significance of this paper is the presentation in a unified way of the main concepts of green computing and computational intelligence, as well their current and future applications. We strongly believe that this paper could help lay the foundation for a new hybrid area combining green computing with computational intelligence, which would be very important because up to now both areas have been flourishing apart and they could both benefit by interacting with each other.