The environmental cost of AI: Google and Amazon's sustainability reports reveal rising emissions

It's no secret that AI is a hog, consuming energy and water like no digital technology before it. Now we know just how much Big Tech's pursuit of AI is costing the environment. Both Google and Amazon released their sustainability reports this week, and the numbers aren't pretty.

Each company has pledged to zero-out its carbon emissions in the coming years, but AI has made those goals a lot harder to hit. Google's total carbon emissions are up 25% since last year, Amazon's are up 16%. A close reading of the reports suggests that both Amazon and Google will have to make some serious, and potentially costly, adjustments to their businesses if they're going to achieve their net-zero targets.

Neither company comes out and blames AI directly for the rising emissions, but there's plenty of indirect evidence. Both Amazon and Google acknowledge their energy use has increased significantly in the last year as use of AI has risen. Both talk about carbon intensity — essentially, how much pollution a company generates for every dollar of revenue it brings in — a metric China has used over the last several years when negotiating climate treaties even as its emissions were skyrocketing.

And both devote several pages touting how AI can benefit the environment, a case of 'protesting too much,' to borrow some Shakespeare. The picture gets clearer the deeper you dig into the data. Both companies are actually doing OK when it comes to carbon pollution from energy purchases.

Years of buying renewable power have helped keep a lid on things, though that may change in the near future as tech companies, including Google, have begun to invest heavily in natural gas power plants to keep pace with AI's power demands. 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.