In the last year, Meta has financed the establishment of at least twelve natural gas power stations, including a single project that will utilize enough natural gas to produce as much electricity as the entire state of South Dakota consumes.

Today, Meta disclosed to TechCrunch that it has withdrawn from the RE100 initiative, a corporate renewable energy program, after a decade of involvement. According to a spokesperson from Meta, the decision to part ways was mutual.

This withdrawal concludes months of Meta increasing its investments in fossil fuels to power its AI data centers and raises the crucial question: What does “clean energy” signify for a company that continues to construct gas plants while still identifying as renewable?

The RE100 initiative, a project by the Climate Group, a nonprofit based in the U.K. co-founded by former Prime Minister Tony Blair, offers policy and technical assistance to companies aiming to switch to 100% renewable energy. Competitors of Meta, such as Apple, Google, and Microsoft, remain part of the group’s 444 members. Recharge News was the first to report Meta’s exit.

While Meta did not elaborate on the reasons for its departure — and the Climate Group did not respond to TechCrunch’s request for comment — the nonprofit has recently revised its guidelines for companies, enforcing stricter reporting on their progress towards renewable energy objectives. Previously, Meta had informed RE100 that it would “operate its entire operations on renewable electricity by 2020.”

Like many technology firms, Meta’s adoption of AI has driven it to secure substantial energy for its data centers, and while the company continues to acquire renewable energy, it has increasingly turned to natural gas.

Meta’s initial move was a 200-megawatt behind-the-meter gas power plant in Ohio, announced in June of the previous year, designed to supply power to one of its data centers.

Two months later, Meta revealed plans to construct three large natural gas power plants in Louisiana to provide electricity to its Hyperion data center. Then in April, the firm announced it would fund seven additional natural gas power plants for the same project. Together, these ten plants will produce 7.5 gigawatts, generating enough electricity to power South Dakota and more.

A spokesperson for Meta informed TechCrunch that the company remains dedicated to aligning its data center energy usage “with 100% clean and renewable energy.”

That’s a significant commitment. While natural gas burns cleaner than coal, it still emits considerable pollution. A single 1-gigawatt data center operating continuously, powered solely by natural gas, will emit 438 metric tons of nitrogen oxides, 149 metric tons of fine particulate matter, 61 metric tons of sulfur oxides, and 298 metric tons of carbon monoxide. These pollutants are linked to various health problems, including asthma, cancer, cardiovascular conditions, and dementia, among others.

Meta can still assert that it is 100% renewable by acquiring environmental attribute certificates. These certificates enable businesses to invest in solar farms in Arizona, for example, while constructing a data center in Ohio. As long as the solar farm generates enough energy in one year to counterbalance the data center’s consumption, Meta reports that as 100% renewable.

Most companies have approached their renewable energy goals through annual matching, but some, like Microsoft, are aiming to align their electricity consumption on an hourly basis. This more rigorous method would better synchronize power generation with data center energy usage. It also motivates companies to invest in projects that combine renewables with battery storage, similar to Google’s earlier efforts in Minnesota, rather than relying on polluting sources like Meta’s Hyperion power plants.

Meta is not alone in its pursuit of natural gas — both Google and Microsoft have recently invested in significant fossil fuel initiatives — but it has made the largest investment. While stepping back from a voluntary industry organization isn’t usually major news, the timing, amidst Meta’s expansion into fossil fuels, makes this shift difficult to overlook.