Green or Greenwashing? The Hidden Truth Behind Sustainable Data Centers (4/4)

In our previous blogs, we outlined several efforts aimed at making data storage more sustainable. However, some critics remain unconvinced, often dismissing these efforts as little more than marketing rhetoric. They argue that green claims must be substantiated with hard data.

Let’s take a closer look at some of the critical perspectives on the green initiatives of data centers:

• Harvard Business Review (2021): Many tech companies claim to use “100% renewable energy” by purchasing RECs (Renewable Energy Certificates). However, these do not guarantee that the energy is locally or simultaneously available. It’s more of an accounting mechanism than a physical green transition.
• Nature (2018): This journal points out that even technological improvements in efficiency cannot keep up with the rapidly growing energy demand: “Efficiency doesn’t solve the growth problem.” The authors call for strict limits on unnecessary data storage and the energy-intensive training of AI models.
• The Guardian (2024): Many hyperscale data centers are still being built in water-scarce regions like Arizona, where large amounts of water are needed for cooling. This exacerbates local water shortages and impacts communities already struggling with limited water access — increasing both ecological and social pressure.
• MIT Technology Review (2025): Training large AI models such as GPT-4 requires massive amounts of energy. These energy-intensive processes often go unreported in sustainability disclosures, leading to a systematic underestimation of AI’s true environmental footprint.
• Greenpeace Reports: Greenpeace has analyzed the energy sources of major tech companies. They criticize the lack of transparency and the use of green energy claims that do not reflect real changes in the companies’ energy supply chains. An interesting article is Microsoft, Google, Amazon – Who’s the Biggest Climate Hypocrite?
• EFF (Electronic Frontier Foundation): Cloud providers often publish only aggregated or high-level sustainability data, making it difficult to determine the actual energy usage of specific workloads or regions. EFF calls for detailed, granular transparency per workload and location, so that users can make more informed decisions about their digital footprint.
• EEB (European Environmental Bureau): The EEB warns that current EU legislation falls short in managing the full environmental impact of data centers. They advocate for a stricter and more coherent legal framework that addresses not just energy use but also water consumption and material impact.

Although the transition to more sustainable data centers has begun, serious concerns remain about the credibility of many green ambitions. Critics warn against an overreliance on marketing claims and accounting tricks like RECs, which say little about the actual ecological impact. Without transparent data on energy use, water consumption, and CO₂ emissions, sustainability claims remain difficult to verify. Moreover, the overall energy footprint of data centers continues to grow, driven by expanding AI workloads and unchecked data retention.

Sustainability, therefore, requires more than just smarter technology. It demands bold decisions about what data we truly need to keep, and what we can afford to let go.