A warning sign about AI’s real cost, courtesy of Google and Amazon

Rather, most of Amazon’s and Google’s growing carbon footprint comes from so-called Scope 3 emissions — a catch-all category covering pollution a company doesn’t directly control, like the goods and services it buys or the products it sells. For companies like Amazon and Google, Scope 3 includes things like GPU purchases and the use of a company’s products, like phones and tablets.

Google lumps together two categories of Scope 3 emissions — capital goods and use of sold products —though it admits the latter is small enough to not be material. (Most of Google’s hardware products are small devices that don’t consume a lot of electricity.) That likely leaves data centers as the main driver. Last year, Google’s Scope 3 emissions increased by 2.1 million metric tons, which means they’re now double what they were in 2019, the year Google uses as its baseline when assessing its performance.

Amazon’s rising Scope 3 emissions mostly come from capital goods and fuel and energy. The former can include data centers and warehouses, which can help explain why Amazon’s Scope 3 emissions spiked higher than Google’s. Still, a good chunk is probably data centers. “To meet strong customer demand, in 2025 we added more data center capacity globally than any other company, including more than 1.2 gigawatt (GW) in Q4 alone,” Amazon wrote in the report.

That kind of spending helps explain why decarbonization is suddenly getting so much harder. For years, the biggest contributor to their carbon footprints was energy for offices and more modestly sized data centers. That could easily be canceled out buying renewable power. 

AI has upended that approach. While tech companies could still use renewables plus batteries to power their data centers, they’re starting to fall back on fossil fuels. It’s a trend that will make their net zero pledges that much harder to deliver, but it’s not irreversible.

The more pernicious emissions come from the construction and outfitting of data centers themselves. The steel and cement industries are both heavy polluters, and while startups are working on low-to-zero carbon approaches, they’re still not ready to deliver at the scale that tech companies need. 

Then there are the GPUs and memory chips powering the AI boom. Semiconductor manufacturing uses lots of energy, and many of the world’s leading-edge chip factories are located in Asia, where the electrical grids remain dominated by fossil fuels. Making matters worse, many of the chemicals used in those factories are also potent greenhouse gases, capable of warming the atmosphere thousands of times more than an equivalent amount of CO2. The bingeing on chips has probably inflated both Amazon’s and Google’s carbon footprints.

None of these problems are intractable, though Amazon, Google, and their peers have their work cut out for them. To deliver on their net-zero pledges, they’ll need to ramp up their renewable energy purchases, invest heavily in advanced steel and cement manufacturing, and buy many millions of tons of carbon removal credits. It’s still possible, but their embrace of AI hasn’t made it any easier.