CO2Stats

The Kettle Question

An hour of video calling

Emissions and water for one hour of a video call, with the camera on and off. Each figure counts something different: open its details to see what.

The figures at a glance

Carbon emissions, highest first. On the scale, each line is ten times the one before.

  1. 150 to 1,000 g CO2 per hour of videoconferencing or streamingOne hour of videoconferencing or streaming, Purdue/Yale/MIT study
  2. 10.2 to 21.6 g CO2e per hour of video call with the camera onOne-hour Teams call with the camera on, over 4G (network data only)
  3. 4.8 to 10.8 g CO2e per hour of video call with the camera offOne-hour Teams call with the camera off, over 4G (network data only)

One hour of videoconferencing or streaming, Purdue/Yale/MIT study

  • 150 to 1,000 g CO2 per hour of videoconferencing or streaming
  • 2 to 12 litres of water (kind not known) per hour of videoconferencing or streaming

Turn off that camera during virtual meetings, environmental study saysPurdue University (press release on Obringer et al., Resources, Conservation & Recycling, 2021), press release, 2021-01-14

This figure is disputed: its details say how.

Details

Just one hour of videoconferencing or streaming, for example, emits 150-1,000 grams of carbon dioxide (a gallon of gasoline burned from a car emits about 8,887 grams), requires 2-12 liters of water and demands a land area adding up to about the size of an iPad Mini. But leaving your camera off during a web call can reduce these footprints by 96%.

What one action is
One hour of videoconferencing or streaming (the release adds that leaving the camera off cuts these footprints by 96%)
Counts
processing and transmission of internet data
Model or version
Footprints per gigabyte of data for 18 platforms, online gaming and web surfing, using models from Madani's research group and known energy use per gigabyte of fixed-line internet
Method
Estimated from the data volume of each platform multiplied by per-gigabyte carbon, water and land footprints of electricity for internet data; the researchers call the estimates rough.
Claimed by
Independent: Renee Obringer, Benjamin Rachunok, Debora Maia-Silva, Maryam Arbabzadeh, Roshanak Nateghi and Kaveh Madani (Purdue, Yale, MIT)
Paid for by
Purdue Climate Change Research Center, Purdue Center for the Environment, MIT Energy Initiative, Yale MacMillan Center
Dispute
Félix Mortas (arXiv preprint, 2026) measured data use on Microsoft Teams calls over 4G and found that turning the camera off roughly halves data use and the related emissions, which it presents as a challenge to this study's 96% figure, noting that the study is based on estimates and modelling rather than experimental data. https://arxiv.org/abs/2601.06045

History

  • Added.

One-hour Teams call with the camera off, over 4G (network data only)

  • 4.8 to 10.8 g CO2e per hour of video call with the camera off

Assessing the Carbon Footprint of Virtual Meetings: A Quantitative Analysis of Camera UsagearXiv (Félix Mortas, independent researcher), preprint, 2025-12-16

Details

Turning the camera off reduces these emissions to 4.8 to 10.8 g of CO2e per hour.

What one action is
A one-hour Microsoft Teams call with the camera off, measured at 8.76 MB per minute on a 4G connection
Scope
network
Counts
electricity for mobile (4G) network data transfer
Leaves out
data centres; end-user devices; screen sharing
Model or version
Measured data volume times mobile-network energy intensity (kWh/GB, minimum and maximum from the literature) times the French electricity carbon intensity (ADEME, 79.1 gCO2e/kWh)
Place
France
Method
Mobile data use was read from the operator app before and after each of nine 30 to 60 minute Teams meetings and converted to emissions with mobile-network energy intensities and the French grid factor; figures as in version 2 (18 January 2026).
Claimed by
Independent: Félix Mortas

History

  • Added.

One-hour Teams call with the camera on, over 4G (network data only)

  • 10.2 to 21.6 g CO2e per hour of video call with the camera on

Assessing the Carbon Footprint of Virtual Meetings: A Quantitative Analysis of Camera UsagearXiv (Félix Mortas, independent researcher), preprint, 2025-12-16

Details

For video calls, having the camera on results in emissions ranging from 10.2 to 21.6 g of CO2e per hour.

What one action is
A one-hour Microsoft Teams call with the camera on, measured at 18.07 MB per minute on a 4G connection
Scope
network
Counts
electricity for mobile (4G) network data transfer
Leaves out
data centres; end-user devices; screen sharing
Model or version
Measured data volume times mobile-network energy intensity (kWh/GB, minimum and maximum from the literature) times the French electricity carbon intensity (ADEME, 79.1 gCO2e/kWh)
Place
France
Method
Mobile data use was read from the operator app before and after each of nine 30 to 60 minute Teams meetings and converted to emissions with mobile-network energy intensities and the French grid factor; figures as in version 2 (18 January 2026).
Claimed by
Independent: Félix Mortas

The calculator uses this figure: Video call, camera on (4G mobile network only, France).

History

  • Added.
Back to top