You will see many things in the upcoming Spiderwick Chronicles on Disney+, including faeries, family secrets, and Christian Slater. But one thing director and producer Kat Coiro is hoping you don’t see is single-use plastic. That’s because besides helming movies like Marry Me and shows like Girls 5Eva, Kat is a proponent of Lights Camera Plastic, a Hollywood initiative to make sustainable living an onscreen essential.

“The goal is to make waste like plastic water bottles obsolete in the world of movies,” Koiro explains. “It’s kind of like smoking—there was a time when every movie character smoked cigarettes, and then there was a push to stop glamorizing it. We stopped seeing tons of characters smoke. Single-use plastic should be the same way!” Which explains why in recent episodes of She-Hulk, characters have lunch with reusable utensils and sip their coffee from thermoses instead of styrofoam cups.

Here’s how Kat is helping optimize her film sets on behalf of the planet, what other Hollywood insiders are doing to help, and why J.Lo makes the best test subject.

You’ve been working in Hollywood for over a decade. How eco-minded is the film and TV industry today?

It’s horrific! [Laughing.] Sorry! But you know, everybody says they want to make a change. But when push comes to shove, it always comes down to, “It’s just too expensive. There’s nothing we can do.” I grew increasingly frustrated with that. So on Marry Me, I thought, “If I can’t make this set sustainable, at least I can determine what’s on the screen. Because what’s on the screen has a huge influence on culture.”

So what did you do?

I basically made a rule. I told the production crew and the design team, “No single-use plastic on screen!” We filmed scenes at a school—all the kids have reusable water bottles. J.Lo needed a coffee cup; we made her a blinged-out one. Owen Wilson’s character carried a lunchbox, not a plastic bag full of takeout, and his clothes were all sustainably-made or secondhand. I was very adamant about weaving this into the storytelling. And while I was doing that, Sheila Morovati from the organization Habits of Waste was doing Lights Camera Plastic—which was the exact idea I was practicing! So we teamed up.

Did you get any resistance from film studios or on set?

The great thing is that it’s a small step and it’s a very doable step. On Marry Me and She-Hulk, it was literally just me telling the [props and set] departments, “Hey, you know this scene where they’re having lunch? Can we replace the plastic cups and the takeout cartons with reusable pieces? Can J. Lo have a thermos? Can the courtroom scenes have glasses of water, instead of plastic bottles?” For Spiderwick Chronicles, we started the initiative in pre-production so it’s been fully embraced.

So there won’t be any single-use plastic in Spiderwick Chronicles?

Everyone’s really excited about it! Before we began filming, the writers took out anything in the script that’s single-use plastic or waste. I have a script supervisor scouting for plastic bottles in the background of shots. We’re trying to show the industry, “Hey, you can easily do this.” And the goal is to use Lights Camera Plastic as the gateway to bigger environmental change.

This is cool. Why isn’t every studio doing this?

People are overwhelmed by how badly things are going. They think environmentalism is too big to tackle. But if we all do what we can, that’s a lot of doing! If every props person uses a Swell bottle instead of a plastic bottle, yes. That’s something. It just takes one person to start change.

How do celebrities play into this?

Whoever has power on set should use it for good. That’s really it. Like, one person who really lined up with me was Mark Ruffalo. He came onto the set [of She-Hulk] and he sees that Hulk’s house is full of junk food. He says, “Kids are gonna watch this; can we have healthy food? Like nuts and fruit and beans, stuff that’s good for us?” He was so nice about it, but he obviously cared very much. And I thought, “Oh, I have an ally. This is awesome.”

What’s one big misconception around single-use plastic?

That it’s convenient. It’s actually not! Let me explain. If I have my Swell water bottle on me, and I have my thermos of hot tea. That means when I’m thirsty, I don’t need to stop somewhere and try to buy water. It means when I want tea or coffee, I’m not at the mercy of whatever is around—I already have the good stuff that I like. But somehow we’ve been hoodwinked into believing that single-use drinking vessels are easier. Look, I have kids. I have a demanding job. I promise you that this is the most efficient way. And it means I get nice coffee. And it means I’m being nice to the planet.

How has your experience with Lights Camera Plastic changed your relationship with the environment?

One experience I did have recently is, I traveled north to stand in solidarity with the Water Protectors in Northern British Columbia. When I went up, I met their chief. I drank from a sacred river. And we all must understand that what they’re doing has very little to do with “their” land, and much more to do with all of us; our children and our children's children. I was called up there to tell their story. I wish more people in Hollywood would address this, you know? Hollywood loves talking about human rights. This is a huge human rights catastrophe with a huge environmental impact. And we can all learn about it and raise our voices.

It’s almost Hallmark Movie season. Do you think there should be a rom-com about the environment? Would that help?

Oh god! Here’s my answer to that: I think movies that lead with messages don’t work. I think that entertainment has to come first, and then if you can guide the audience through a great story and characters, you make a much bigger impact than if you set out to tell them how to think. I am not in the business of telling people what to do. I’m going to tell a great story and entertain the hell out of you.

Watch She-Hulk, directed by Kat Coiro, on Disney+ Now