Microsoft has signed a deal with energy firm Stockholm Exergi to help it meet its ambitions to become a net zero carbon company by 2030 by absorbing emissions from biomass power plants.

The deal will see some 3.33 million tonnes of permanent carbon removals from bio-energy with carbon capture and storage (BECCS) at a plant in Värtan, Stockholm.

But scientists have previously expressed doubt that this method of carbon removal is an efficient way to reduce global emissions. A 2018 letter to the European Parliament signed by nearly 800 scientists said that “cutting down trees for bioenergy releases carbon that would otherwise stay locked up in forests, and diverting wood otherwise used for wood products will cause more cutting elsewhere to replace them”.

It called on the body to restrict the forest biomass eligible under the directive to residues and wastes from industries such as paper-making and timber products, which would ultimately degrade and release carbon into the atmosphere anyway...