In a bold move to cut its massive carbon footprint, Microsoft is investing in a surprising new method — burying human waste.
The tech giant announced on Thursday it will buy 4.9 million metric tons of carbon removal over 12 years from Vaulted Deep. The US-based company pumps “bioslurry” — a mix of human and farm waste — 5,000 feet underground to trap carbon emissions.
This waste, usually difficult to treat and often polluting water systems, is injected deep into natural rock formations. In return, Microsoft receives carbon credits to help meet its climate goals.
Microsoft’s carbon output has ballooned in recent years, driven in part by its expanding artificial intelligence ventures. From 2020 to 2024, the company emitted around 75.5 million tons of CO2.
Now, it hopes projects like Vaulted Deep will help it reach its target of becoming carbon negative by 2030. By 2050, Microsoft aims to remove more carbon than it has released in its entire history.
Vaulted Deep’s co-founder Julia Reichelstein explained the waste is “sludgy, often contaminated” material that usually causes environmental harm. “Instead, we put it really deep underground for permanent carbon removal,” she said.
Each ton buried underground earns Microsoft a carbon credit, currently valued at around $350 per ton.
Brian Marrs, Microsoft’s senior director of energy and carbon removal, praised the plan. “It’s not just about storing carbon — it’s removing a public nuisance,” he said.
This unusual strategy may signal a new frontier in fighting climate change.
