Microsoft

Microsoft has acknowledged a 25% increase in its CO2 emissions in the last fiscal year. This increase has been attributed to the expansion of data centers dedicated to artificial intelligence and the decision to halt the purchase of "unbundled" renewable energy certificates, which are sold separately from the physical production of electricity. This was confirmed by the company's executives in the environmental report published on July 9.

A figure of 34 million tons of CO2 equivalent circulated online, which was never declared by Microsoft. That number, derived from a graph in the report, actually represents a counterfactual scenario: how much the company would have emitted without the reduction efforts already in place, from the energy efficiency of Xboxes to sustainable aviation fuels and the decarbonization of the Surface supply chain. The actual figure declared for the year stands at about 20 million tons, still 25% more than the previous period.

The report, signed by Vice President and President Brad Smith alongside Sustainability Lead Melanie Nakagawa, attributes the increase "mainly to the expansion of data center infrastructure" and the choice to suspend the purchase of unbundled renewable certificates. Scope 3, encompassing indirect emissions along the supply chain, remains the heaviest item in the balance sheet. However, the real anomaly of the year concerns Scope 2, the component related to direct electricity consumption: it rises from just under 2% to 13% of the total.

Why Unbundled Energy Certificates Are Considered Greenwashing

Unbundled renewable energy certificates, by definition from the U.S. Environmental Protection Agency, are sold separately from the electricity actually generated. Those who purchase them can claim to be powered by renewable sources without consuming a single watt of that energy, merely financing the distant development of new facilities. This practice is classified as a form of greenwashing by many environmental observers, although companies defend it as a financial lever for the sector.

As early as February 2025, Microsoft announced it would stop purchasing "non-additional" certificates, explaining that it wanted to redirect those funds toward more sustainable interventions: direct emissions reduction, CO2 removal, and agreements for clean electricity supply. In the report, the company reiterates that its goal remains to become carbon negative by 2030, even while admitting that this choice could temporarily take it out of a position of carbon neutrality.

Not all the numbers go against the declared goals. For the first time, Microsoft has restored more water than it has extracted, over 14 million cubic meters in the fiscal year, a milestone that helps offset the water impact of its latest data centers.

The underlying issue remains. The growth in consumption related to artificial intelligence makes it increasingly difficult for large cloud providers to reconcile climate commitments with infrastructure expansion. Microsoft attempts to justify the increase with the transparency of its new accounting criteria, but the 2030 target will depend on how quickly the company can replace unbundled megawatts on paper with clean energy actually fed into the grid.