The analysis does not account for the purchase of market-based instruments that are meant to represent investments in new renewable energy in the US and that tech companies buy to offset the pollution from their electricity consumption. These instruments include renewable energy certificates.
Instead, the research focuses on the pollution generated in the specific area where the data is being processed, in an accounting approach known as “location based.”
“Unlike carbon emissions, the health impacts caused by a data center in one region cannot be offset by cleaner air elsewhere,” said Shaolei Ren, associate professor at UC Riverside.
Google, Meta, and Microsoft said their usage of back-up generators was below the estimated levels for the research, which is based on a median estimate of usage from publicly disclosed levels. The companies did not give detailed, per-location figures for their usage of back-up generators.
Google added that the health cost estimates were overstated and that it did not “account for our clean energy purchases in the local markets where we operate” and therefore “promotes an inaccurate emissions estimate generated under false pretenses, undermining the progress of clean energy resource growth and creating a false narrative of health harms.”
The company added that its purchases enable it to achieve, on average, around 64 percent carbon-free energy.
Microsoft said it was focused on “delivering significant local, economic, social, and environmental benefits to the communities where we operate.”
Meta said it complies with air quality requirements and remains committed to “maintaining net zero greenhouse gas emissions for our global operations, building innovative and sustainable infrastructure, reporting transparently on our sustainability goal progress, and supporting the communities where we operate.”
Due to where data centers are located, such as West Virginia or Ohio, the health impact disproportionately affected lower-income households, according to the research.
Ren said there was an opportunity for tech groups to reverse the trend of a “growing public health threat” by strategically placing their data centers in less populated locations to have less impact.
According to a separate report by Berkeley Lab, supported by the Department of Energy, US data center energy use represented about 4 percent of total US electricity consumption in 2023 and is forecasted to rise to between 7 and 12 percent by 2028, driven largely by AI workload demand.
“There is a concern around pollution as [AI] is energy intensive and people are using it more and more,” said Antonis Myridakis, a lecturer in environmental sciences from Brunel University London. “It is an important factor contributing to air quality and public health, it is not something we can ignore.”
Additional reporting by Kenza Bryan and Camilla Hodgson
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