Big Tech’s big bet on a controversial carbon removal tactic

Bioenergy with carbon capture and storage can scale faster than other approaches. But some experts are dubious about the climate benefits.

MIT Technology Review | Oct 15, 2025
By James Temple

A pile of wood at a Drax facility in Mississippi, which converts biomass into pellets to power industrial facilities. AP Photo/Gerald Herbert

Over the last century, much of the US pulp and paper industry crowded into the southeastern corner of the nation, setting up mills amid sprawling timber forests to strip the fibers from juvenile loblolly, long leaf, and slash pine trees.

Today, after the factories chip the softwood and digest it into pulp, the leftover lignin, spent chemicals, and remaining organic matter form a dark, syrupy by-product known as black liquor. It’s then concentrated into a biofuel and burned, which heats the towering boilers that power the facility—and releases carbon dioxide into the air.

Microsoft, JP MorganChase, and a tech company consortium that includes Alphabet, Meta, Shopify, and Stripe have all recently struck multimillion-dollar deals to pay paper mill owners to capture at least hundreds of thousands of tons of this greenhouse gas by installing carbon scrubbing equipment in their facilities.

The captured carbon dioxide will then be piped down into saline aquifers more than a mile underground, where it should be sequestered permanently.

Big Tech is suddenly betting big on this form of carbon removal, known as bioenergy with carbon capture and storage, or BECCS. The sector also includes biomass-fueled power plants, waste incinerators, and biofuel refineries that add carbon capturing equipment to their facilities.

Since trees and other plants absorb carbon dioxide through photosynthesis and these factories will trap emissions that would have gone into the air, together they can theoretically remove more greenhouse gas from the atmosphere than was released, achieving what’s known as “negative emissions.”

The companies that pay for this removal can apply that reduction in carbon dioxide to cancel out a share of their own corporate pollution. BECCS now accounts for nearly 70% of the announced contracts in carbon removal, a popularity due largely to the fact that it can be tacked onto industrial facilities already operating on large scales.

“If we’re balancing cost, time to market, and ultimate scale potential, BECCS offers a really attractive value proposition across all three of those,” says Brian Marrs, senior director of energy and carbon removal at Microsoft, which has become by far the largest buyer of carbon removal credits as it races to balance out its ongoing emissions by the end of the decade.

But experts have raised a number of concerns about various approaches to BECCS, stressing they may inflate the climate benefits of the projects, conflate prevented emissions with carbon removal, and extend the life of facilities that pollute in other ways. It could also create greater financial incentives to log forests or convert them to agricultural land. 

When greenhouse-gas sources and sinks are properly tallied across all the fields, forests, and factories involved, it’s highly difficult to achieve negative emissions with many approaches to BECCS, says Tim Searchinger, a senior research scholar at Princeton University. That undermines the logic of dedicating more of the world’s limited land, crops, and woods to such projects, he argues.

“I call it a ‘BECCS and switch,’” he says, adding later: “It’s folly at some level.”