Apple announced Tuesday it plans to be carbon neutral by 2030, joining a bunch of companies in a clean crusade. Microsoft plans to be carbon negative in 2030; Unilever carbon neutral by 2039 and Amazon carbon neutral a year later.

Apple’s emissions from making its products accounted for three quarters of its carbon footprint last year. To reduce that, the company is going to have to compel the firms in its supply chain to emit less carbon, too.

More than 70 Apple suppliers have already committed to using only renewable energy. The tech giant said that all suppliers will have to “identify, manage, reduce and responsibly control air emissions emanating from their operations that pose a hazard to the environment.” Those suppliers will have to monitor progress on their emissions controls, Apple said.

That sounds like a tall order, but if you’re a company as big as Apple, said Joshua Rhodes, a founding partner of energy industry consultancy IdeaSmiths, it’s easier than it might sound.

“The contracts you’re signing are worth billions and billions of dollars, and so you can tell your supply chains jump, and they’ll say, how high?” he said.

Elika Kordrostami, assistant professor of marketing at Rowan University, said even if Apple has a concrete plan in place to achieve its carbon neutrality, it has to update consumers about how the plan is coming to fruition because of skepticism about large corporate goals.

Kordrostami said most big companies already have statements of intent on their websites about all sorts of social responsibility.

“[About] how they are trying to protect the environment, how they’re trying to make sure that, for example, the ingredients of their products and services are supplied ethically,” she said.

She’s not convinced consumers will make sure the companies are actually following through on their promises before they buy.

Correction (July 23, 2020): An earlier version of this story inaccurately described Apple’s plan for its manufacturing supply chain. The text and audio have been corrected.