With the international community’s efforts to respond to climate changes progressing in the world, Green IT technologies have also developing rapidly. As green IT technologies against climate change has emerged as the agenda of social sciences, the concept of green IT has evolved into two types: greening of IT and greening by IT. In order to cope with the long-term climate change, it is necessary to discuss whether the greening of IT and the greening by IT evolve in some way. In this context, this study reviewed in depth green IT research trends as well as concepts of greening of IT and greening by IT to respond to climate change. Furthermore, it proposed a life cycle assessment (LCA) as an indicator for assessing green IT. The results of this study are expected to contribute to solving political problems with green IT and continuing research in the climate change era. They are also presented to make a contribution to the development of IT industry in Korea by presenting the concepts of greening of IT and greening by IT. Based on this, in this study, as a precondition of Green IT, Discussed by emphasize the need for environmental load measurement method based on the entire life cycle of the product is finished.