Microsoft’s Carbon Emissions Rose 25% in 2025, Driven by Data Center Growth

Microsoft's 2026 sustainability report, as flagged by GeekWire, shows the company's carbon emissions climbed 25 percent in 2025, reaching 34 million metric tons before what the company calls "select interventions." Microsoft attributes the increase primarily to rapid data center expansion, plus a February 2025 decision to stop buying unbundled renewable energy certificates. The jump puts fresh pressure on the company's self-imposed goal to be carbon negative by 2030, meaning it must remove more carbon than it produces.

What happened

Microsoft published its 2026 sustainability report showing that its carbon emissions totalled 34 million metric tons in 2025, on a basis the company describes as “without select interventions.” That is a 25 percent rise compared to the prior year, according to reporting by GeekWire.

The company points to two main causes. First, it has been aggressively expanding its data center footprint, which consumes enormous amounts of electricity. Second, in February 2025, Microsoft stopped purchasing what it calls “non-additional, unbundled renewable energy certificates,” a common but widely criticised accounting tool that lets companies claim renewable energy credits without directly funding new clean power generation.

Microsoft set a goal several years ago to become carbon negative by 2030. That means the company must eventually remove more carbon from the atmosphere than it emits. At 34 million metric tons and rising, the gap between where it is and where it needs to be is wide.

Why it matters

Data centers are the physical backbone of AI. Every large language model, every image generator, every AI-powered search result runs on servers that consume power around the clock. As Microsoft pours investment into AI infrastructure, the energy demand tied to that infrastructure grows with it.

The decision to stop buying unbundled renewable energy certificates is a double-edged story. On one hand, those certificates were criticized as low-quality offsets that did little for actual emissions reductions. On the other hand, dropping them means the reported emissions number goes up, making the company look worse on paper even if the underlying accounting is now more honest.

For businesses and consumers who rely on Microsoft cloud services, Azure AI tools, or Microsoft 365, this report is a reminder that the environmental cost of cloud computing is real and measurable. Vendor sustainability claims are worth scrutinising, not just accepting at face value.

Our take

The 2030 carbon-negative target always looked ambitious. With emissions up 25 percent in a single year and data center construction accelerating, it looks harder than ever to hit. To Microsoft’s credit, dropping the unbundled certificates is a more honest accounting approach, but honesty about a problem is not the same as solving it.

From where we sit, the broader pattern is clear: the AI infrastructure race is producing very real environmental costs that are easy to ignore when you are focused on benchmark scores and product launches. A few things worth noting:

• A 25 percent annual emissions increase is steep by any standard, not a rounding error.
• Microsoft is not alone. Every major cloud provider is building out similar infrastructure at speed.
• The 2030 deadline is now less than five years away, and the trajectory is moving in the wrong direction.

We are skeptical that voluntary corporate sustainability targets will close this gap without structural changes to how data centers are powered. Watch for whether Microsoft announces firm power purchase agreements for new nuclear or large-scale renewables in its next few reports.

What to do about it

If your business uses cloud services and has its own sustainability commitments, now is a good time to ask your vendors for scope 3 emissions data, not just their top-line pledges. Check whether the renewable energy claims in their contracts are backed by direct generation agreements or by the kind of unbundled certificates Microsoft just stopped using. That distinction matters when you are trying to report your own supply chain emissions accurately.

Source: The Verge · AI