Microsoft burnishes green cred by paying Swedes to burn biomass and bury CO₂

Schemes like this are just a license to pollute for tech giants, or so critics say

Updated Microsoft has expanded its deal with Stockholm Exergi to buy 500,000 tonnes of permanent carbon removal annually over ten years. Critics argue such deals give polluters cover rather than drive real climate action.

The newly minted contract builds on a 10-year agreement signed by the two firms a year ago covering 3.33 million tonnes of permanent carbon removal. Both involve Exergi's bio-energy with carbon capture and storage (BECCS) facility at Stockholm, near the Värtan strait.

With the extension, Microsoft's total commitment rises to 5.08 million tonnes of permanent carbon removals over ten years - an amount the companies claim is the largest deal of its kind to date.

BECCS aims to remove carbon dioxide from the atmosphere by burning biomass - a term that can encompass wood, wood waste, agricultural waste, food scraps, and other biological material - then capturing the resulting CO₂, and permanently storing it underground. The planned facility in Stockholm is designed to remove up to 800,000 tonnes of CO₂ annually. Proponents describe the process as carbon negative, meaning it removes more CO₂ than it emits - though this claim remains subject to ongoing scientific and policy debate.

Microsoft will use the carbon removals covered by this agreement to offset its own emissions and, in line with Swedish government policy, will be reported as contributing to the country's climate targets - similar to how corporate emission reductions are counted toward national goals.

Exergi previously stated that it plans to start handing over the carbon removal certificates to Microsoft from 2028, and to continue for a period of ten years.

The updated agreement will see the Swedish firm deliver carbon removal certificates to Microsoft under strict quality requirements. These include criteria for sustainable sourcing of forest biomass developed in collaboration with Redmond, as well as quantification of net removals and comprehensive monitoring, reporting, and verification (MRV) processes.

Exergi received an environmental permit for the project last year, with the construction of the carbon capture unit, liquefaction, and intermediate storage happening this year. Exergi claims the biomass feedstock for the project will be safeguarded to ensure sustainable management and that feedstock is not sourced from wood that would otherwise be used for long-lived products. Permanent geological storage will take place "in the Nordic region."

But some environmental groups have criticized offsetting carbon emissions as providing corporations with a license to pollute and a distraction from decarbonization efforts.

The International Energy Agency (IEA) describes the ECCS as "the only carbon dioxide removal technique that can also provide energy," but warns that the necessary infrastructure to transport and store the captured CO₂ lags behind what is needed.

The world's forests are rich in nature and carbon ... Cutting them down, burning them, and capturing the carbon makes climate change worse

US-based environmental advocacy group the Natural Resources Defense Council goes further, labeling BECCS as a hoax and claiming that it actually increases greenhouse gas emissions.

"The world's forests are rich in nature and carbon. The best thing for our climate is to leave them standing. Cutting them down, burning them, and capturing the carbon makes climate change worse," it states.

We asked both Microsoft and Exergi for comment.

The Redmond megacorp has a number of other agreements regarding offsetting its CO₂ emissions. In January, it extended a deal with Brazilian company Re.green to plant millions of seedlings over 16,000 hectares across Brazil, earning the tech giant carbon 3.5 million tons of carbon removal credits over 25 years.

Microsoft also signed a contract with petroleum giant Occidental Petroleum last year to buy 500,000 metric tons of carbon dioxide removal credits over six years.

This followed the revelation a year ago that the cloud and software giant had actually increased its carbon dioxide emissions by nearly 30 percent since 2020, the year when it set itself the goal of becoming "carbon-negative" by 2030. ®

Updated to add:

Microsoft didn't answer all of our questions but sent through a statement from Brian Marrs, its Senior Director, Energy and Carbon Removal. Marrs said: "Microsoft uses a reduction-first strategy to lower emissions (such as the use of low carbon construction materials), but we recognize that carbon dioxide removal (CDR) projects are essential for reaching carbon negative. We’re focused on CDR projects that deliver a combination of science-backed carbon removals and local economic benefits."

The Windows-maker also pointed us to a blog post from January 2020 promising the tech giant would be "carbon neutral" by 2030.