Microsoft ramps up plans to capture carbon from burning wood

Microsoft is doubling down on a controversial plan to capture carbon dioxide emissions from wood-burning power plants. It announced a contract with energy company Stockholm Exergi to capture 3.33 million metric tons of carbon emissions from a biomass power plant in the Swedish capital.

But the jury is still out on whether wood-burning power plants actually help fight climate change or make things worse. Prominent environmental groups including the Center for Biological Diversity and Friends of the Earth International have criticized the strategy as a “false solution.” And back in 2018, nearly 800 scientists signed a letter to the European Parliament asking it to stop supporting the use of wood for bioenergy.

Exergi runs a power plant in Stockholm that runs on wood pellets and residue from forestry waste, also known as forest biomass. Since that fuel comes from trees that can theoretically regrow to capture as much carbon dioxide as the power plant releases by burning wood, proponents see it as a carbon-neutral source of energy. The European Commission actually considers biomass burning its largest source of renewable energy, even though it’s been tied to deforestation across Europe and the US.

Microsoft and Stockholm Exergi are taking that idea one step further by adding machinery to the power plant that’s supposed to capture a majority of its carbon dioxide emissions before it can escape into the atmosphere. By doing so, they believe they can achieve negative emissions — taking more CO₂ out of the atmosphere than this source of energy produces. Negative emissions technologies like this have become popular with companies trying to offset the environmental impact of their carbon pollution.

But a growing body of research suggests the math doesn’t quite add up for bioenergy with carbon capture (BECCS). Devices that scrub CO₂ out of smokestack emissions aren’t able to capture 100 percent of the carbon dioxide. And then there are additional emissions from clearing forests and transporting wood to be used as fuel. With that in mind, several studies have found that BECCS isn’t carbon negative after all and actually adds greenhouse gas pollution to the atmosphere.

Microsoft declined to respond to The Verge’s request for comment.