With a general overview of both arguments, I would say it causes less harm to the environment as expected. From the environmentalist’s view, data centres are needed to keep up with the cloud server capacity intake resulting in high energy consumption meaning high level of consumption of fossil fuel which is harmful to the environment.
On the other hand, computer experts argue that there is a resource virtualization that has a single running multiple operating system that run simultaneously. This causes a tremendous reduction in the server footprint meaning the server occupying less space which is beneficial to the ecology thus reduce power consumption.