Calculate the Carbon Footprint of your Online Video Calls
Ever wondered what the environmental impact of your online webinar might be? Fill in the details below in order to estimate what the CO2 output could be.
About this Calculator
This calculator is designed to provide an estimate as to the amount of carbon produced from a call via a video conferencing app such as Zoom, Skype or Teams. The results are indicative only, the methodology and assumptions are described below.
How the Calculator Works
Estimations for the amount of carbon emitted from each call are based on the following equation:
CF = C.P.(n.t.(Du+Dd))
- CF = Total carbon footprint of the call (gCO2e)
- C = Carbon intensity of power generation (gCO2e/kWh)
- P = Power required to transfer 1 GB of data (kWh/GB)
- n = Number of participants on the call
- t = Length of call (seconds)
- Du = Data upload rate based on the type of call (GB/s)
- Dd = Data download rate based on the type of call (GB/s)
This equation takes the total time of the call and multiplies it by the number of particiapnts on the call and the combined data upload and download rates. This estimates the total amount of data transfered between the participants during the call. The value of data transferred is then multiplied by an energy intensity value for each GB of data transferred. Finally this value is multiplied by the average carbon intensity of each kWh.
The calculation only covers the carbon emmissions caused by the transfer of data during the call, it does not take into account the energy used by the devices that the call participants are using or the transfer of data from the local router that the participant is using. The energy usage of the device can be significant relative to the energy usage of the call itself , however it is highly dependent on the device. Using a smartphone is more efficient than a widescreen desktop for example, and the variance between devices can be large.
The calculation does not account for the carbon emmissions associated with the water usage of data centers. Some data centers use water to provide cooling for the servers, the volume of water used by these centers can be significant . Pumping, treating and disposing of this water all has associated carbon emmissions that are not dealt with here.
Data and Uncertainties
The following data is used as part of the calculation.
Carbon Intensity of Electricty Production
|Rep of Ireland
These values are representative average values, they are predominantly year averages from 2017 data provided by the EEA. The value can shift per day and by region of the country. For example in days of low wind the power provide by renewable wind energy in the UK drops and the short fall is made up by burning extra gas or coal, thus increasing the carbon output.
Energy Intensity of Data Transfer
This calculator uses a value of 0.07kWh/GB, this is based on the 2021 paper by Obringer et al.  which in turn is based on calculations performed by Kamiya . There is debate about how to quantify the energy intensity of data transfer, a widely quoted report by the Shift Project  uses much higher energy intensity rates than this value. The Shift Project have stated however that this energy intensity rate may not be suitable for calculating high bit rate activities such as streaming . Another more conservative intensity rate is provided by the Website Carbon Calculator .In an online talk Malmodin, who has written a number of papers on the subject  has suggested that an energy per byte ratio is not suitable and energy consumption rates should be time dependent .
For the sake of simplicity this calculation assumes that all data transferred is via wired broadband, energy intensity rate for mobile data such as 5G would be higher .
Data Transfer Rates
The data transfer rates are based on the system requirements listed on the Zoom website , these figures are representative of the transfer rates of other services such as Skype and Teams. Note that these are minimum requirements so actual transfer rates may be higher during a call.
The distance traveled by an average car calculation is based on diving the total CO2 of the call by the average gCO2/km of cars in the UK. The average value used is 127.9gCO2/km .
Comments, Corrections and Feedback
Please get in touch if you would like more information about the calculator, if you would like to request any additional features or you have any feedback or corrections. You can contact me via this contact form or by sending an email to [email protected].
- Factcheck: What is the carbon footprint of streaming Netflix - G Kamiya, 2020
- The overlooked environmental footprint of increasing Internet use - R Orbinger et al, 2021
- CO2 Intensity of Electricity - EEA 2017
- Lean ICT: Towards digital sobriety - The Shift Project 2019
- Did the Shift Project really overestimate the carbon footprint of online video? - The Shift Project 2020
- Website Carbon - Wholegrain Digital
- The energy and carbon footprint of the ICT and E&M sector in Sweden 1990-2015 and beyond - J Malmodin et al - 2015
- Science & Society Forum: Växande IKT-sektor och fler datacenter – hur påverkas elförsörjningen? - Kungl. Ingenjörsvetenskapsakademien IVA 2020
- System Requirements - Zoom
- Car CO2 Emmissions - Which? 2021