If you have Zoom fatigue, you’re not alone. But now you have a good reason to keep your camera off during a Zoom call: You’re doing your part to save the planet.

According to one study, leaving your camera off reduces the carbon footprint of a videoconferencing session by up to 96%. The numbers come from a 2021 report from researchers at Purdue University, Yale University, and the Massachusetts Institute of Technology in Science News. A carbon footprint report from Mozilla Advocacy recently brought it back to light.

What sort of savings is that in real-world terms? Well, one hour of videoconferencing or streaming emits 150 to 1,000 grams of carbon dioxide. (That’s as much as the equivalent of 11% of the emissions from a gallon of gasoline.) It also requires between 2 and 12 liters of water.

That footprint is comprised of the air-conditioning and liquids used to cool the servers in data centers. Every small task online comes with some sort of carbon footprint. And some are bigger than others.

For instance, Zoom hosts 3.3 trillion meeting minutes—or 55 billion hours—every year. If even a quarter of those events were audio-only, it could have serious ecological effects, saving a minimum of 18.2 million pounds of carbon dioxide (and possibly much more: as much as 121 billion pounds, according to the study—an admittedly wide range).

Or, if you prefer, those dark screens would be the equivalent of planting another 2 million trees on the planet.

Zoom, of course, isn’t the only online tool where the environmental effects could be broadly reduced by users. Streaming content on Netflix or Hulu in standard definition rather than in high definition could reduce carbon emissions by as much as 86%, the researchers estimated.

A four-hour binge session on Netflix is the equivalent of driving a gas-powered car for one mile. Annually, the streaming company (which has vowed to halve its emissions by 2030 and buys carbon credits) produces roughly 1.1 million metric tons of CO2, the equivalent of 240,000 passenger cars.

Even streaming music has a impact on bigger greenhouse gasses than LP, cassette, or CD sales.

Artificial intelligence, though, is threatening to be the technology that has the largest environmental footprint.

The technology required to power the servers behind generative AI requires a ridiculous amount of cooling. Nvidia’s chips are at the heart of AI tools like ChatGPT, and it takes thousands of those to run a single AI system.

A report from Stanford looked at the CO2-equivalent emissions of several machine learning tools. ChatGPT-3 was, far and away, the service with the biggest impact. In 2022, it was estimated to create 502 metric tons of CO2.

That’s the equivalent of a single person flying from New York to San Francisco more than 500 times or the lifetime emissions of eight gas-powered cars.

Tech companies are working on ways to reduce their footprint, but users can help in the meantime. Whether it’s switching to audio on your calls, turning off autoplay on your streaming services, or cutting short your play sessions with AI, a small step can contribute to substantial change. Plus, with your camera off, you don’t have to worry about how you look on conference calls.