Every time you generate an image or ask an AI to write you a cover letter, somewhere a data center is drawing power — a lot of it. The environmental impact of AI is real, growing, and poorly understood by most users.
Training vs. inference
There are two distinct phases of an AI model's carbon life. Training — the one-time process of building the model — is enormously energy-intensive. GPT-3's training run was estimated to emit roughly 550 tons of CO₂, equivalent to about 60 round-trip flights between New York and London. GPT-4 and similar frontier models are believed to have training costs orders of magnitude higher, though companies don't publish exact figures.
Inference — actually using the model — is cheaper per query but adds up at scale. Every ChatGPT query uses roughly 10x the energy of a Google search. With hundreds of millions of daily queries, the cumulative impact is significant.
Data center water consumption
Less discussed than energy: AI data centers consume enormous amounts of water for cooling. Microsoft reported that its water consumption increased by 34% in 2022, largely attributable to AI workloads. A 2023 study estimated that training GPT-3 required roughly 700,000 liters of fresh water.
The renewable energy picture
Major cloud providers (Google, Microsoft, Amazon) have made commitments to match their energy consumption with renewables. Google claims to match 100% of its electricity with renewable energy purchases. However, "matching" isn't the same as "running on" — renewable energy certificates can be purchased from sources disconnected from actual consumption. The grid the data center actually draws from matters, and many regions still rely heavily on natural gas peaker plants during high-demand periods.
What can users do?
The individual user's impact is real but modest compared to the systemic level. The more tractable interventions are at the infrastructure level: demanding that AI companies publish actual energy and emissions data, choosing providers with verifiable (not just claimed) renewable commitments, and supporting policy that requires data center energy transparency.