The hidden pollution cost of online meetings

It is often assumed that online meetings are better for the environment than physical meetings. That is not always the case.

  • A one-hour audio call consumes about 36 MB of data per person.
  • A one-hour standard-definition video call consumes about 270 MB per person.
  • A one-hour high-definition video call consumes about 540 MB per person.
  • A one-hour ultra-high-definition video call consumes about 1.3 GB per person.

Assuming an average of one one-hour meeting a day involving two people, 250 days a year, then:

  • The audio-only calls would emit 0.08 kg of CO2.
  • The standard-definition video calls would emit 0.6 kg of CO2.
  • The high-definition video calls would emit 1.1 kg of CO2.
  • The ultra-high-definition calls would emit 2.8 kg of CO2.

An average tree can absorb about 10 kg of CO2 per year. Here’s the equivalent number of people calling that would be required in order for it to be necessary to plant one tree in order to offset the pollution:

  • 270 people for audio only
  • 36 for standard-definition video
  • 18 for high-definition video
  • 7 people for ultra-high-definition video.

The average CO2 emissions from new passenger cars registered in the European Union in 2018 was 0.1204 kg of CO2 per kilometer. Thus, on a yearly basis:

  • The audio-only calls would be the equivalent of driving 0.7 of a km.
  • The standard definition video calls would be the equivalent of driving 5 km.
  • The high-definition video calls would be the equivalent of driving 9 km.
  • The ultra-high-definition calls would be the equivalent of driving 23 km.

It’s much better to have an online meeting than to drive to a meeting, it would seem. Well, it’s not that simple. The above estimates relate to the streaming costs for online meetings. There are also processing costs. In many organizations meetings are saved and stored and sometimes watched later by others. There are costs relating to the devices used for the meetings.

Based on initial calculations, we estimate that streaming may represent no more than 5% of the total costs. So, for meetings using high-definition video, for example, based on our scenario above, it could be the equivalent of driving 375 km per year. This still a quite reasonable figure, but is a lot higher than the streaming-only costs of 9 km per year.

What happens if people drive to the office and go on conference calls with other people in that very office? What happens if far more meetings now occur online than were held offline? What happens if far more people attend online meetings?

These are the things that I’ve noticed. When working with larger organizations, I’ve regularly been part of meetings with anywhere from 20 to 100 people; far more people than would have attended if the meetings had been held in a physical space.

Used wisely, digital can be better for the environment. However, time and time again, I have found that digital behaves as an accelerant, as a duplicator, as a copier, as a reproducer, as an encourager of wasteful behavior.  

Digital is not green. What is so much better than digital meetings are no meetings, fewer meetings, meetings that take a lot less time, meetings that are useful.

GB per hour for audio calls, Zoom

GB per hour for video calls, Taraspan

Electricity Intensity of Internet Data Transmission, J. Aslan, K. Mayers, J. Koomey, C. France, Journal of Industrial Ecology, 2015

Greenhouse gas reporting: conversion factors 2018, GOV.UK

What is the carbon footprint of streaming video on Netflix? George Kamiya, International Energy Agency in Paris.

Cisco digital forecasts 2017 – 2022, Cisco