The cloud already has a larger CO2 footprint than the worldwide aviation industry. With increasing digitalization and cloudification this trend will continue if we don't do anything about it. Many Kubernetes installations are greatly oversized in terms of the resources actually required and thus contribute unnecessarily to global warming. How big is the footprint of your cluster and its workloads? In this session we will outline and demonstrate different approaches and technologies for measuring, scaling, scheduling and resource tuning that help to make your K8s clusters green(er).