Shifting from on-site data centers to the public cloud is the action most likely responsible for an 80%+ reduction in a healthcare company’s data center carbon footprint.

What’s going on here?

Moving from traditional, company-run data centers to large public cloud providers usually has the biggest impact on emissions because:

  • Public clouds run at much higher utilization , so less idle hardware wastes power.
  • Hyperscale data centers are designed for extreme energy efficiency (advanced cooling, modern hardware, optimized workloads).
  • They increasingly use or procure renewable energy at scale, which directly cuts carbon intensity per kilowatt-hour.

Compared with this, actions like:

  • Adding electric cars to the fleet
  • Encouraging employees to bike or walk to work
  • Building individual data centers at each client site

all have relatively minor or even negative effects on data center emissions, because they don’t materially change how digital workloads are powered and cooled.

Why public cloud can cut >80%

In many assessments and learning materials, the “80%+ reduction” scenario is explicitly tied to the move from on‑premise data centers to public cloud infrastructure. This reflects real-world trends where:

  • Consolidating workloads into fewer, highly efficient facilities slashes total energy use.
  • Better efficiency and higher server utilization compound with cleaner energy sourcing, producing large emissions reductions for the same compute.

So, if you see this kind of multiple‑choice question, the best answer is:

Shifting from on-site data centers to the public cloud.

TL;DR: The huge drop in data center carbon footprint (over 80%) almost certainly comes from migrating workloads from in-house data centers to energy‑efficient, often renewable‑powered public cloud facilities.

Information gathered from public forums or data available on the internet and portrayed here.