Reducing the environmental impact of enterprise IT begins with collecting data and reporting metrics to establish a baseline. But with dozens of potential metrics and complex accounting to consider along with the highly distributed and diverse nature of hybrid IT portfolios, this can be a daunting task. For many CIOs and their IT operations teams, this is also a new task. This paper is a straightforward, “how to get started” guide that identifies energy consumption as the fundamental data point to start with and gives a simple 3-step framework to start measuring the environmental impact of the IT estate.