The fashion industry has a significant role to play in accelerating or decelerating climate change. It currently makes up more than 8% of global carbon emissions, which is more than all international flights and maritime shipping combined. And yet, the industry is only just beginning to reckon with how much carbon it is spewing into the atmosphere. Only a smattering of brands have plans to tackle the problem, and even fewer are carbon neutral.

Marco Bizzarri, Gucci’s CEO, wants his brand to take responsibility for every last bit of greenhouse gas it emits. Until now, the brand has been working to reduce its emissions and offset any carbon coming out of Gucci-owned facilities. But today, Gucci—a luxury fashion house on track to generate €10 billion ($11.2 billion) by 2020—announces an ambitious new plan to become completely carbon neutral throughout its entire supply chain. Bizzarri says this extends into the deepest recesses of its manufacturing operations, including the tanneries where it sources its leather and the factories where raw materials are processed. Each unit of carbon that isn’t eliminated will be offset by supporting forest conservation projects in developing countries through an international initiative called REDD+. All of the brand’s emissions from 2018 have been measured and offset, and it is currently tracking its 2019 emissions, which will be totaled up and offset next year.

As I reported earlier this year, it is very difficult to track how much carbon a fashion brand discharges because apparel and footwear supply chains are so vast and complex. Some companies buy materials from middlemen, so they can’t trace them all the way back to their their original source, like cotton fields or cattle farms. While some labels are beginning to track how much they emit in their stores and offices, very few go all the way to their partner factories and raw materials. When sneaker startup Allbirds did this earlier this year, it made news.

Bizzarri is well aware of this, but he believes that the industry shouldn’t wait to act until it perfects its carbon calculations: Brands need to act in good faith based on the best available information. “We’re using many mathematical models from different universities,” Bizzarri tells me. “Of course, there is always room to perfect these methodologies—and we are open to talking to anybody who can give us suggestions—but I really believe that we just need to start somewhere.”

Math aside, the fact is that the bulk of carbon emitted in most industries is released at the earliest parts of the supply chain, in the cultivation of raw materials, rather than in the transportation or sale of products. This means that Gucci now has the burden to both measure and offset these emissions. For instance, Gucci must figure out how much carbon is emitted at each of the tanneries where it buys its leather. “Tracking our impacts earlier in the supply chain is not as easy as measuring our own direct impact,” says Bizzarri.

To do so, Gucci is relying on standards laid out by the Greenhouse Gas Protocol, an international organization that helps companies measure emissions. There are three levels: The most basic, called Scope One, involves identifying emissions on property that the company itself owns or controls, such as their trucks, offices, and retail stores. The next, called Scope Two, takes into account the emissions from the electricity the company buys. The vast majority of companies working toward carbon neutrality, including Kering, Gucci’s parent company, focus on these two scopes. Gucci is now going beyond Kering’s own mandates by tracking and offsetting Scope Three, which encompasses all of its indirect emissions through third-party factories and suppliers.