Published on Jun 24

The carbon footprint of email - Top facts and questions

This article examines the carbon footprint of email, a vital tool in both personal and professional communication. Despite its efficiency and convenience, the environmental impact of sending, receiving, and storing billions of emails daily is often overlooked, contributing significantly to the global carbon footprint.

The carbon footprint of email - Top facts and questions

Email has become a vital tool for communication in both personal and professional contexts. It is a pervasive element of modern life, with billions of emails sent every day, therefore it is undoubtedly efficient and convenient. However, its environmental impact is sometimes disregarded. Energy is needed for every email sent, received, and stored, which adds to the global carbon footprint. Several aspects of email's carbon footprint are examined in this article.

How does an email have a carbon footprint?

Every email we send requires power to be displayed, and electricity is also used by the network connection to transport the email. Every server on the internet uses electricity to store email momentarily before forwarding it to other servers.

Understanding the Carbon Footprint of Email

The typical brief email exchanged between two laptops releases 0.3g of CO2e. If the email is transmitted from phone to phone, this figure drops to 0.2g CO2e, and if it is a spam email that a filter has detected, it drops to 0.03g CO2e. On the other hand, emissions rise noticeably with lengthier emails.

An email with a picture or attachment may release up to 50g of CO2e, but a long email that takes ten minutes to send and three minutes to read releases only 17g. The device's embodied carbon makes up most of these emissions; the networks and data centers used in the sending and storage of these emails, as well as the device's energy consumption, have minor contributions.

An individual's average email usage produces 3 to 40 kg of CO2e over the course of a year. This is the same as traveling 10 to 128 miles in a modest gasoline-powered vehicle. Even though emails individually contribute very little to global emissions, the 3.9 billion email users worldwide make this contribution substantial.

Email has a significant contribution to the overall carbon footprint of digital technology because of the cumulative effect of billions of emails exchanged every day.

Top facts about the carbon footprint of email

  1. Global Impact of Email: 2019 saw a stabilization of the world's CO2 emissions from energy usage at 33.2 gigatons, partly due to lower emissions from power generation in wealthy nations. This was made possible by boosting nuclear power, switching from coal to natural gas, and growing renewable energy.

    Email's influence on the environment also attracted attention in the meantime. An office worker's daily email intake of 126 can result in a yearly CO2e effect per worker of 184 kg, which is equivalent to the emissions of certain poor nations. While advancements in clean energy technology are essential, attempts to lessen the total carbon footprint connected with digital communication may also be aided by cutting out on pointless emails, controlling spam, and improving data storage. This emphasizes how crucial it is to address energy use as well as digital behaviors in order to achieve environmental sustainability.

  2. Efficiency Paradox: Efficiency improvements in email technology have made it easier and cheaper to send and store messages. However, this convenience has led to a massive increase in the number of emails people send and keep. Even though each email uses a small amount of energy, the sheer volume of emails globally means a lot of energy is still used. This includes energy for sending emails, storing them in data centers, and keeping servers running. So, while emails themselves are efficient, the overall impact on the environment from all the energy used is significant.

  3. Data Centers' Energy Consumption: Data centers require a lot of energy to run and cool servers. The need for data centers rises with the growth of digital services, like email, which raises energy consumption and increases carbon emissions, particularly if the data centers are fueled by fossil fuels. A major factor in this need is the use of email. Every email costs energy to transmit and store, especially those with big attachments, as stated before. The amount of energy required to process and store emails increases along with their volume.

    Approximately 1% of the world's power is used in data centers, and this percentage is growing. One of the biggest energy users is cooling systems. In order to lessen their influence on the environment, data centers must:

    • Boost energy efficiency by upgrading the hardware and cooling.
    • Make use of solar and other sustainable energy sources.
    • Optimize operations to cut unnecessary energy use.
  4. Corporate Responsibility: Businesses may lessen their environmental effect considerably by addressing the carbon footprint of their digital operations. Controlling email usage is important since it affects data centers' energy usage.

    To reduce their digital carbon footprint, businesses may do the following:

    • Simplify Communication: Motivate staff members to send fewer emails and concentrate on using more effective ways to communicate.
    • Optimize Data Storage: Put in place procedures for routinely deleting superfluous information and outdated emails.
    • Adopt Renewable Energy: Make the switch to renewable energy sources for data centers and other digital infrastructure.
  5. Carbon Cost of Deleting Emails: As the process of deleting emails requires energy, we now know that it has a minor carbon cost. Data must be sent from your device to the server, which requires energy, in order to delete an email. A single email deletion consumes very little energy, yet it nonetheless produces some CO2 emissions, but the emissions mount up when millions of people remove emails.

    However, the initial carbon cost of deleting emails is often outweighed by the energy and carbon emissions saved by not holding them for an extended period of time. Since data centers require a lot of electricity to operate and store vast volumes of data, decreasing the volume of stored emails aids in reducing their total energy consumption and related carbon emissions. To reduce the overall digital carbon footprint, the carbon cost of deleting emails is a tiny but essential step in the right direction.

  6. Renewable Energy's Role: Renewable energy sources like solar, wind, hydro, and geothermal power are crucial in reducing this carbon footprint. These sources produce electricity without emitting greenhouse gases, making them essential for powering data centers and digital infrastructure. Major companies like Google, Microsoft, and Amazon are transitioning their data centers to renewable energy, significantly cutting their carbon emissions.

    Key strategies include:

    • Powering Data Centers with Renewable Energy: Reducing emissions by using clean energy.
    • Improving Energy Efficiency: Utilizing advanced cooling systems and efficient practices.
    • Adopting Distributed Energy Solutions: Implementing localized renewable energy installations.
    • Corporate Sustainability Goals: Companies adopting renewable energy as part of their sustainability strategies.
    • Economic Viability: The decreasing cost of renewable energy makes it increasingly feasible.
  7. Global email traffic: In 2021, over 306 billion emails were sent daily, a number expected to exceed 376 billion by 2025. The increasing volume of email traffic presents a challenge. Even with improved efficiency, the overall energy consumption continues to rise due to the growing number of emails.

Top questions about the carbon footprint of email

  1. How does email compare to other digital activities in terms of carbon emissions? An hour of Facebook use generates roughly 2 grams of CO2, an hour of Instagram scrolling produces about 1.5 grams, and an hour of Netflix standard definition viewing produces about 55 grams. About one gram of CO2 is released by each participant during an hour-long Zoom meeting, and 20 grams are released during an hour of online gaming. In light of this, email uses less carbon than other internet activities like gaming and streaming videos. Therefore, you could say that the use of email is much healthier for the environment in comparison to other digital activities.

  2. What kind of data is required for assessing the carbon footprint of emails? In order to evaluate the total environmental effect, this involves monitoring power use, estimating CO2 emissions from that energy use based on where the energy originates from (such as coal or renewable sources), and taking into account variables like the frequency, volume, and types of emails sent.

  3. Are there email providers that are better for the environment? Indeed, there are email services that are better for the environment than others. They accomplish this by employing renewable energy sources, such as solar or wind power, and enhancing the energy efficiency of their data centers. Providers further lessen their environmental effect by buying renewable energy credits or taking part in carbon offset schemes. Selecting providers that openly provide information about their sustainability initiatives might encourage the adoption of greener digital practices. Here are some examples:

    • Google: Invests heavily in renewable energy to power their data centers and offices.
    • Microsoft: Committed to achieving carbon negative status by 2030 through renewable energy investments.
    • Apple: Powers many data centers with solar and wind energy, focusing on sustainability.
    • GreenGeeks: Offers eco-friendly hosting solutions with renewable energy credits.
    • ProtonMail: Operates data centers sustainably with a focus on energy efficiency.
  4. Can I calculate the carbon emissions from my personal email account? This is a rough estimate on how to calculate your email carbon emissions:

    • Research Energy Use: Check if your email provider uses renewable energy and how efficiently their data centers operate.
    • Estimate Data Transmission: Calculate the average amount of data (including attachments) you send per email and how often you send emails.
    • Convert to Carbon Emissions: Suppose your email provider uses 0.6 kWh of electricity per email. If their emissions factor (CO2 per kWh) is 0.5 kg CO2/kWh: Carbon emissions per email =

0.6 kWh * 0.5 kg CO2/kWh = 0.3 kg CO2 per email.

  • Calculate Total Emissions: If you send 100 emails per month: Monthly carbon emissions = 100 emails * 0.3 kg CO2 per email = 30 kg CO2 per month.
  1. What actions can individuals take to help lower the environmental impact of using the internet and email?
    • Cut Down on Email Volume: Reduce the number of pointless emails you send.
    • Employ Effective Communication: For brief conversations, choose voice or instant messaging.
    • Handle Subscriptions: Remove yourself from unsolicited newsletters and emails.
    • Limit Attachments: Don't attach huge files; instead, use file-sharing services.
    • Eliminate Superfluous Emails: Frequently purge and discard emails. One way to do this is to use an Inbox cleaner tool like Against Data.
    • Turn on energy saving by putting electronics to sleep when not in use.
    • Select services from suppliers who use renewable energy to show your support for renewable energy.
    • Inform Others: Spread knowledge on digital carbon footprints.
    • Select Green Hosting: Look for hosting companies that use environmentally friendly methods.
    • Advocate for Change: Back laws that encourage the use of renewable energy sources and energy efficiency.


In summary, email is an essential tool in modern life, yet its widespread usage adds significantly to the world's carbon footprint. Comprehending the environmental impact necessitates taking data center energy-intensive activities and email transmission efficiency into account.

A person's personal carbon footprint related to digital communication can be reduced by selecting email providers who use renewable energy and by implementing strategies like cutting out on pointless emails and attachments.

By encouraging responsible digital behavior and energy conservation, these actions help create a more sustainable future.

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