Cloud Footprint

How much internet did you use today? How many emails did you send, how many Google searches did you do, or how many photos did you take and upload to the cloud storage? How much do you share on social media every day? Do you have daily video-conferences for work or with friends? Did ever think about the ecological footprint of all these actions? Do you know how much energy a single search on Google or an hour-long meeting on Zoom consumes?

Carbon footprint is defined as the amount of carbon dioxide released into the atmosphere due to the activities of an individual, institution, or community. To expand the definition a little more, we may say, it is the total amount of greenhouse gases that, for example, a person emits directly or indirectly into the atmosphere while continuing their daily activities and lifestyle. According to the World Health Organization, it is the measure of fossil fuel consumption and emission caused by your activities in units of CO₂. If you are curious about your individual carbon footprint, you can try various calculation systems offered online by organizations, such as the one on WWF’s website. It is possible to obtain approximate results by answering questions on your personal usage of a car or public transport, your diet, your shopping habits, the size and the kind of your house. However, getting clear results is quite difficult, because there are too many variables involved and experts often disagree on what should be included in these calculations.

Although it is relatively easy to calculate the carbon footprint of your transportation habits, such as the gasoline you fill in the tank of your car or the number of flights you take in a year, calculations become difficult when you try to include other things like food production or technology use/consumption. For example, let’s consider the stages to take into account for a specific amount of tomatoes you buy: the diesel consumed by the tractor used for soil cultivation (should we also add the energy consumed during the production of that tractor in the factory?); electrical energy spent for the establishment of the irrigation system (pumps, pipes, etc.) required for watering the plants and for irrigation until harvest time; manufacture, distribution and field application of products such as herbicides and insecticides; the production of synthetic fertilizers (or the carbon emissions from animals raised for obtaining natural animal fertilizers); harvesting, packaging, and often international distribution and access to markets; and the miles we drive to buy those tomatoes… As you can see, there is such an intricate and complex system behind it that it is almost impossible to clearly determine the carbon footprint of any product. (It is always a good idea to choose locally grown food whenever possible, especially since products such as distribution and synthetic fertilizers account for the largest share of carbon footprint regarding agricultural products.)

Apart from tomatoes, it is even harder to calculate the carbon emissions caused by technologies such as mobile phones that are now hardwired into everyone’s daily lives. It does not seem possible to make individual calculations for all the components of a smartphone whose raw materials were collected from countries like Australia and Chile, assembled in China, and sold in the USA. Moreover, since these are still quite solid consumer products that we can actually hold in our hands, it is still possible to envision certain question marks regarding their carbon footprint.

How about the carbon footprint of a Google search? Or sending an e-mail? Or every single photo you upload to the cloud system? Before answering these, it makes sense to first take a look at the infrastructure systems and data centres that maintain and sustain the global internet network.

Data centres are enormous facilities operating 24/7, connected to the global internet network, where applications and data are stored. While some are used only for data storage purposes, some are specialized in artificial intelligence operations, and others host corporate applications and databases. All of them are in communication with each other. Some data centres are so large and equipped with so many computer systems (may spread over hundreds of acres of land) that they are called “data farms”, partly due to how they look from outside. Cloud systems that we use to store our photos, videos, e-mails, and applications consist of a series of such huge data centres. The world’s largest cloud data centres are managed by companies including Google, Microsoft, Amazon, and Facebook.

These centres constantly consume energy, as they continuously operate and host an astonishing number of electronic devices. In addition, they are constantly cooled with air conditioners to prevent computers, servers, and other devices from overheating. Therefore, they are CO₂ plants all by themselves. (Some facilities are built in the North Pole to ease down the cooling process!)

According to some estimates, computers, tablets, smartphones, the internet, and all the infrastructure systems sustaining the internet account for 3.7% of global greenhouse gas emissions. This is pretty much equal to the greenhouse gas emissions of the global airline industry. Some experts predict that this ratio may double by 2025.

When we divide the approximate total of 1.7 billion tons of greenhouse gas emissions resulting from the production and the use of digital technologies equally among all internet users (which is about 4.1 billion people), every single one of us seems to be responsible for an annual greenhouse gas emission of around 400 grams.

Of course, in the IT sector, which is now subjected to serious competition, institutions have turned to renewable energy sources and they try to cut down on using fossil fuels to satisfy their customers. For example, Google, working in many other fields besides its famous search engine, including data storage and artificial intelligence, announced that it has been using renewable resources to support all of its cloud systems since 2017 and will meet all its electricity demand by using clean energy by 2030.

So, when making a choice for both your individual and corporate cloud needs, you can now prefer companies that benefit from renewable energy sources.

A Single Google Search

Statistics show that Google’s searching service is used 3.5 billion times a day. That makes around 40,000 searches per second and 1.2 trillion per year. Each search reaches data centres at an average distance of 2,500 km and then returns to our computer screen, using about 1,000 computers for this, and the whole process takes only 0.2 seconds! The usage rate of Google’s search engine, on the other hand, has been recently increasing at an annual rate of 10-15%.

There are various opinions on the internet about how much energy a single Google search consumes or how much fossil fuel consumption it causes. While some estimates claim that each search emits 7g of CO₂, which is quite high, Google corrects this figure as 0.2g (stating that 1000 Google searches emit the same amount of CO₂ as the amount released when an average car running on gas travels 1 km).

You are not limited to Google when it comes to making searches on the internet. For example, the engine provided by Ecosia states that it saves 1 kg of CO₂ from the atmosphere for every search you make, because they spend the money earned through searches on planting trees wherever required in the world.

The Cloud System

With the widespread use of mobile devices, in particular, photo, video, and application data piling up on tablets and phones are stored in data centres called cloud systems. For a reasonable monthly or annual fee, you get a certain amount of space and use that space to store the data you do not want to delete here. Thanks to fast internet networks, you can access these whenever you want and from any device.

The Journey of Data to the Clouds

The files you wish to keep are first divided into data packages and travels to your modem in rows. Then, thanks to fiber-optic cables, these packages move at the speed of light through the infrastructure systems that include various servers, routers, and network switches, finally reaching the buildings where the cloud systems are located: the data centres. The file you want to upload to the cloud is then forwarded to one of the millions of units in these data centres and is “saved”. Every stage of this entire process consumes energy.

However, there is again no clear consensus on exactly how much energy this process consumes, as exactly what processes should be taken into account is debatable. According to a study by Carnegie Mellon University in 2017, the transfer and storage of 1 GB of data consume 7kW/h of energy. (Studies taking into account the standard energy sources in the USA claim that every 100 GB of data stored in the cloud equals 0.2 tons of CO₂ emission). Another study gives the same figure as 3.1 kW/h, making the average somewhere between 3 and 7 kW/h. If you prefer to save that 1 GB of data on your computer instead of uploading it on the cloud, the figure drops to 0.000005 kW/h. So, uploading your data to the cloud instead of saving it on your computer consumes almost 1 million times more energy.

An article published last February in Science states that the efficiency of cloud technology has increased significantly in recent years, with processing power in data centres increasing six-fold between 2010 and 2018, while energy consumption rose only 6%. “The public thinks these massive data centres are energy, bad guys,” said Eric Masanet, the lead author of the study. “But those data centres are the most efficient in the world.”

In addition to Google searches and cloud systems, online movie streaming services (such as Netflix) are said to be a serious source of greenhouse gases, although there are disagreements on this issue as well. According to some studies, watching movies for an hour on Netflix and traveling 6 km by car running on fuel both emit the same amount of CO₂ (3.2 kg). According to this calculation, with an approximate total of 165 million hours of viewing per day, Netflix alone causes 300 million tons of CO₂ emission per year. This is as much as the total greenhouse gas emissions of France!

However, the review of Carbon Brief claims these are 30 to 60 times higher than the actual figures, due to various miscalculations, and the figure given as 6.1 kW/h should actually be 0.12-0.24 kW/h.

Let’s not forgot that e-mails, the indispensable part of our daily lives, also have a carbon footprint. Studies show that a regular email emits 0.3 g of CO₂, and 50 gr if you attach one photograph to it. Considering each mailbox receives dozens (and sometimes hundreds) of spam emails every day, and if you multiply this with all internet users around the world, you end up with an enormous amount of greenhouse gas emissions –for nothing. In case you are wondering, around 240 billion spam mails are thought to be sent every day. A study conducted in the UK reports 64 million junk e-mails being sent every day, which equals to annual CO₂ emissions of 16,433 tons.

To sum up, you may choose to reduce your individual carbon emissions related to internet usage habits by preferring not to upload data to the cloud unnecessarily, avoiding spam emails, and not replacing your technological devices unless it is absolutely necessary.