Learning, teaching, research, work, and travel can be a challenge during a global pandemic, but the changes we’ve all made have also added up to a record drop in global greenhouse gas emissions. It’s also caused a dramatic increase in the amount of time spent on Zoom, GoToMeeting, Microsoft Teams, or other virtual meeting platforms. A recent study1 conducted by researchers at Purdue, MIT, and Yale suggests2 that due to the way that conferencing data is processed and transferred across the Internet, turning off the camera during video calls could reduce the greenhouse gas emissions of virtual conferencing by 96%. Should we all be leaving our camera off during our next virtual meeting to “save the planet”?
Let’s start with the basics. The global climate crisis is the result of billions of small, individual actions every day that add up. Climate solutions can ultimately happen the same way, and so even small actions matter – whether it’s shutting off the computer at the end of the day or turning off lights and A/C when leaving your apartment. When people talk about “the cloud,” they may imagine something “out there” without an impact or cost, so it’s great that this study reminds people that virtual conferencing actually requires tangible infrastructure with a carbon, water, and land footprint.
From a science-based perspective, how does the climate impact of turning off your camera compare to other common recommended actions individuals can take to reduce their carbon footprint?3 Here’s some context:
| Action | Annual GHG reduction (kg CO2 equivalent) |
| One avoided international flight | 8,920 |
| One avoided cross-country flight | 1,100 |
| Eating an Impossible or Beyond Burger instead of a beef hamburger once per week | 172 |
| Replacing incandescent bulbs with a LED 4-pack | 127 |
| One avoided short car trip per week | 126 |
| Turning off desktop computer when not in use | 110 |
| Turning off camera during video conferencing 15 hours/week | 104 |
| Unplugging cell phone charging cube when not in use | 0.4 |
Turning off the camera for 15 hours per week of video meetings does have an impact – certainly more than unplugging an iPhone charger (pro tip #1: don’t bother). And it’s roughly equivalent to other electronics-related actions such as setting your desktop to turn off or hibernate4 when not in use, or changing a few lightbulbs around the house (although doing those things might be less impactful and last longer).
But compared to other lifestyle changes, the impact is less. Avoiding driving for one meeting a week, if video conferencing feels like an acceptable substitute, will save as much as 15 hours of audio-only calls. You can do even more by subbing a plant-forward meal for a meat-centered one, like a veggie patty instead of a beef burger, just once per week.5 And the climate effect of air travel remains a huge impact for those of us who fly: it would take more than a decade of camera-off Zoom calls to save the greenhouse gas equivalent a single cross-country flight, and an entire career’s worth of virtual calls to be the same as one business class flight from NYC to the Mideast!6
It’s not an “either-or” decision. In fact, acting like there’s a climate emergency (pro tip #2: there is) means doing all of these things whenever possible. But in context, it’s important to remember that people may have many reasons for turning their camera off: privacy, clutter, Zoom fatigue, a poor Internet connection, or something else. On the other hand, they also have great reasons to keep them on, including increased social connection and context, body language, reading of lips, and the basic enjoyment that comes with seeing people whom you cannot see in-person.
Your choice to have your camera on or off is probably due to many factors and the carbon impact may not be the most important one. If you don’t need video, feel free to turn your camera off; it’s an easy way to reduce greenhouse gas emissions. If it helps you, feel no guilt about leaving your camera on; if you avoid any travel at all as a result, local or by air, the direct climate benefits will far outweigh the extra emissions from using the camera and seeing your friends, co-workers, or colleagues. Either way, take your meetings in peace and feel good about your decision, whichever it may be on any given call.
See you on the next Zoom!
1. Renee Obringer, Benjamin Rachunok, Debora Maia-Silva, Maryam Arbabzadeh, Roshanak Nateghi, Kaveh Madani, “The overlooked environmental footprint of increasing Internet use”, Resources, Conservation and Recycling, Volume 167, 2021, 105389, ISSN 0921-3449, https://doi.org/10.1016/j.resconrec.2020.105389.
2. The study was covered by Science Daily with the headline “Turn off that camera during virtual meetings, environmental study says”. In actuality, in their paper the researchers were careful to describe the impacts that individuals can have on their environmental footprint without using language that was directive, prescriptive, or guilt-inducing. They also noted that their results were rough given the availability of underlying data, and vary widely from location to location.
3. Full calculations, with data sources and assumptions shown, here. The numbers shown are indicative only; in actuality, they will vary widely based upon the exact equipment and location.
4. Some leave a desktop computer “on” all the time, even nights, weekends, and holidays, either to access it remotely or for convenience. Reducing this practice is a recommendation of the NYU IT Sustainability Initiative, for security reasons as well as climate ones.
5. That’s why NYU has taken the Cool Food Pledge to reduce greenhouse gas emissions from its purchased food 25% by 2030.
6. Need some help deciding whether to fly? Check out this handy decision tree! (NYU version coming soon.)