What is the Truth About Future AI & Data Centre Emissions?
There are lots of stats flying about the efficiency and environmental impact of data centres.
For example, the International Energy Agency (IEA) projects that there will be a substantial increase in these facilities' energy demand in coming years, especially with the rise of AI.
It widely estimates that data centres and data transmission networks each account for 1-1.5% of global electricity use.
However, while some reports highlight increased energy efficiency and efforts to reduce carbon footprints, others reveal significant underreporting of emissions and a growing overall environmental impact, especially with the rise of AI.
Are headline claims a reality?
Data centres worldwide consume around 460TWh of electricity and could jump to around 1,000TWh in the near future — equivalent to Japan's entire annual energy consumption.
It is also estimated that data centres produce around 3% of global carbon footprint when it comes to gas emissions: a similar amount as the aviation industry.
In recent years, leading technology companies have made prominent statements about their efforts to reduce greenhouse gas emissions. However, Guardian analysis predicts data centre emissions are more likely 662% higher than big tech claims, as the surge in demand driven by AI pushes energy consumption even higher.
Between 2020 and 2022, the analysis finds that actual emissions from data centres owned by Google, Microsoft, Meta and Apple were likely around 7.62 times greater than what has been officially reported, with the discrepancy highlighting the hidden environmental costs associated with powering the digital revolution.
“This is a fast-moving space and these numbers come with uncertainty,” Microsoft’s Senior Director of Sustainability, Dr Amy Luers, says.
“Anchoring discussions in trusted sources like the IEA helps cut through the noise and support more informed dialogue.”
However, Amy points out that this should not mean stats from bodies like the IEA should be the only form of truth.
She adds: “But using estimates from the IEA and similar trusted organisations as benchmarks — especially when analysts and media use them to understand and explain why a figure is higher or lower — can help strengthen the dialogue.
“Let’s keep working to cite data, state assumptions and benchmark wherever possible.”
The biggest emitters
Pinpointing a single largest emitter is no easy task thanks to varying reporting methods and data availability, as well as the accountability of direct and indirect emissions, but Amazon Web Services (AWS) — as the world's largest cloud provider — is typically seen as the most prominent data centre emissions emitter.
Microsoft, Google, Meta and Apple are still also significant emitters, though some have suggested their reported emissions often significantly underrepresent the actual levels.
Raw emissions data for AWS data centres specifically are not publicly set out by Amazon in its sustainability reports. However, the 2024 instalment says that while Amazon’s absolute carbon emissions rose from 64.38 million MTCO₂e in 2023 to 68.25MTCO₂e in 2024, the carbon intensity of its business declined, with emissions per dollar of gross merchandise sales falling from 75.6g CO₂e to 72.6g CO₂e, showing improved efficiency despite growth
AWS data centres are however known for their strong operational efficiency, with a global Power Usage Effectiveness (PUE) of 1.15 in 2024, outperforming the public cloud industry average PUE of 1.25.
All five tech companies have made carbon-neutrality pledges, mostly with 2030 as a date set to accomplish them by. Google, for example, aims for 24/7 carbon-free energy for its data centres and offices by the end of the decade and, in the same timeframe, Microsoft has committed to becoming carbon negative, removing all the carbon it has emitted since it was founded.
Google has changed its approach along the way, though. It has ended its mass purchase of cheap carbon offsets and thus stopped claiming that its operations are carbon neutral, which it had claimed to have been since 2007. It is now working to reach net-zero carbon emissions by 2030.
Its 2024 Environmental Report said Google’s overall greenhouse gas emissions shot up by 13% year-on-year in 2023, with AI and data centre energy consumption playing a significant role in this shift.
In the introduction to the report, Google CSO Kate Brandt and Benedict Gomes, SVP, Learning & Sustainability, say: ”In spite of the progress we are making, we face significant challenges that we’re actively working through.
“In 2023, our total GHG emissions increased 13% year-over-year, primarily driven by increased data centre energy consumption and supply chain emissions.”
“A sustainable future requires systems-level change, strong government policies and new technologies. We’re committed to collaboration and playing our part, every step of the way.”
At Amazon, it reached a goal to match 100% of the electricity consumed by its global operations with renewable energy by 2030 – seven years ahead of schedule.
It also achieved a 3% reduction in absolute carbon emissions and a 13% decrease in carbon intensity.
And although AI is seemingly challenging its sustainability credentials on some fronts, Amazon is leveraging AI to optimise solar and storage farms that power its data centres. AWS infrastructure is now up to 4.1 times more energy efficient than on-premises and can reduce workloads’ carbon footprint by up to 99%.
To continue this trajectory, Amazon continues to grow its portfolio of more than 600 renewable energy projects worldwide. It currently has a renewable energy presence in 28 countries and has been the largest corporate purchaser of renewable energy globally for five years in a row.
AWS also aims to be water positive by 2030, returning more water than it consumes.
The future of data centre and AI emissions
AI-optimised data centres alone are expected to quadruple their electricity consumption, with global emissions from these facilities set to surge from 200 million metric tons today to 600 million tons annually by 2030, according to Morgan Stanley,
Construction of new data centres to meet AI demand will further increase embodied carbon, making emissions reduction even more difficult.
But as tech giants scale up infrastructure, climate pledges could face significant strategy crises, meaning they will be increasingly reliant on large-scale investment in renewable energy, carbon capture, and efficiency measures.
Ultimately, aggressive procurement of renewables and stronger policy interventions will be essential to decouple data centre growth from emissions and to align AI-enabled digital expansion with net-zero goals.
As Brad Smith, Microsoft’s Vice Chair and President, said in its sustainability report: “We believe data transparency is critical to driving accountability and progress on climate.”
