Some of the biggest names in tech are joining forces to try something that many before them have failed to do: use trees to cancel out their greenhouse gas emissions. Google, Meta, Microsoft, and Salesforce are creating the Symbiosis Coalition as an effort to support “nature-based” projects aimed at taking carbon dioxide out of the atmosphere.

It’s a tactic companies have used for decades to try to offset their greenhouse gas emissions by planting trees, which take in and store carbon dioxide through photosynthesis. The hope is that paying to restore forests will amplify that process, ostensibly counteracting companies’ carbon footprint. It sounds simple enough on paper. However, a growing body of evidence has shown that this strategy fails time after time.

The Symbiosis Coalition seems to think it can turn things around. Together, the companies have committed to purchasing credits from “high-impact, science-based restoration projects” representing up to 20 million tons of captured carbon dioxide by 2030. They say they’ll vet projects for quality control, aiming to drum up demand for carbon credits that have earned a bad rap because so many carbon offset initiatives have fallen flat in the past.

In one recent example, a study of 26 carbon offset projects across six countries published in the journal Science last year found that few of them succeeded in stopping deforestation. Whatever climate benefits the projects were purported to have were overblown by as much as 300 percent. A separate investigation into one of the world’s leading carbon registries found that 90 percent of its rainforest offsets turned out to be “phantom credits” that likely didn’t represent real-world reductions in greenhouse gas emissions. And a 2022 report by nonprofit watchdog Carbon Market Watch determined that carbon offset credits offered by major European airlines were similarly linked to faulty forestry projects.

A big part of the problem is that it’s difficult to measure just how much carbon dioxide a tree or forest has absorbed, which has led to projects exaggerating how much good they do for the climate. Planting trees is also a tricky endeavor — if they don’t live for hundreds of years, they just wind up releasing all the carbon they’ve stored. Planting the wrong trees in the wrong place, creating tree farms instead of forests, can also harm the local environment. In 2020, Salesforce CEO Marc Benioff backed a World Economic Forum plan to plant a trillion trees — although the research undergirding the effort was quickly criticized by dozens of scientists for grossly overestimating the potential environmental benefits.

Nevertheless, Salesforce, Google, Meta, and Microsoft are confident they can keep history from repeating itself. To try to accomplish that, they worked alongside independent experts to establish strict criteria for forestry projects. Symbiosis also says in a press release that it’ll “involve and compensate Indigenous Peoples and local communities” to work toward “equitable outcomes.” And while it’s starting with forestry projects, Symbiosis says that, over time, it’ll incorporate other strategies, like sequestering carbon dioxide in soil.

“Nature-based projects are complex and challenging to get right and haven’t always lived up to their intended impact,” Symbiosis executive director Julia Strong said in an email to The Verge. “Symbiosis aims to address challenges around nature-based project integrity to date by setting a high-quality bar that builds on best in class market standards and the latest science, data, and best practice.”

The coalition is modeled after a similar initiative called Frontier launched by Stripe, Alphabet, Meta, Shopify, and McKinsey in 2022. Frontier is focused on supporting new technologies to take carbon dioxide out of the atmosphere. Frontier has contracted more than 510,000 tons of carbon removal — but delivered just around 1,700 tons of captured carbon so far.

Both Symbiosis and Frontier are aimed at facilitating deals between carbon removal projects and companies that want to pay for their services. Eventually, Symbiosis hopes more companies beyond its founders will hop on board.

For perspective, all of these efforts still add up to a small fraction of the emissions these companies produce. The 20 million metric tons of nature-based carbon dioxide removal that Symbiosis committed to is just slightly more than the 15.4 million metric tons of carbon dioxide Microsoft alone produced in its last fiscal year.

To be sure, safeguarding the world’s forests does a lot of good for the planet. But exploiting them in the name of fighting climate change hasn’t been a safe bet. Raising the stakes, Big Tech’s greenhouse gas emissions are growing with the rise of energy-hungry AI tools. If companies are serious about taking on climate change, they’ll still have to rein in the amount of pollution they produce in the first place. Even successful forest projects can’t do all the dirty work for them.