 Climate change is a major challenge faced by humanity, with the ICT sector being responsible for up to 2% of global CO2 emissions. Data centers are also contributing significantly to this problem, with their carbon footprint expected to grow rapidly due to technological advancements like cloud computing. However, there has been some progress made towards reducing energy consumption through the European Code of Conduct for Data Center Energy Efficiency program, which encourages companies to improve their energy efficiency. The results show that the average PUE of these facilities is decreasing over time, indicating that voluntary approaches can be effective in addressing climate and energy issues. This article was authored by Maria Evgerina, Paolo Bertaldi, and Luca Castellazzi.