In the digital age, where connectivity is constant, and information flows at the speed of light, it’s easy to think of the internet as a clean, invisible force. But beneath the surface of every email, Google search, social media post, and streamed video is a vast and complex infrastructure, one that consumes enormous amounts of energy and generates significant carbon emissions.

In fact, the internet is a silent but substantial contributor to global greenhouse gas emissions. According to a study by the Shift Project, the digital sector (including data centres, network infrastructure, and user devices) accounted for around 4% of global CO₂ emissions in 2020 – roughly on par with the aviation industry’s pre-pandemic emissions. But how do these emissions occur? And what does this mean for a world striving for net zero? In this article, I take a closer look at the hidden carbon footprint of the internet, what drives these emissions, how it compares with other industries and what we can do to reduce it.

Understanding the Carbon Footprint of the Internet

The internet is not an abstract concept. It is a vast, energy-hungry system made up of three main components, each with its own carbon impact:

1. Data Centres

Data centres are the core of the internet. These are massive facilities filled with thousands of servers that store, process, and transmit data around the clock. Whether you are sending an email, making a video call, or streaming a movie, data centres are working behind the scenes. But these digital powerhouses come with a heavy environmental cost:

• Energy Consumption: In 2022, global data centres consumed an estimated 200 terawatt-hours (TWh) of electricity – about 1% of total global electricity demand, according to the International Energy Agency (IEA). This is more than the energy consumption of some entire countries, such as Argentina or the Netherlands.
• Cooling Systems: Data centres must maintain a stable temperature to prevent overheating. Traditional cooling systems rely on air conditioning, which is energy-intensive. In some regions, cooling can account for 40% of a data centre’s energy consumption.
• Regional Concentration: A significant portion of the world’s data centres are concentrated in a few regions, the United States, China, and Europe. In countries where electricity grids are still heavily reliant on fossil fuels, the carbon intensity of data centre energy use is higher.

A Real-World Example:

Google, one of the largest data operators in the world, reported that in 2020, its global data centres consumed approximately 15.3 terawatt-hours (TWh) of electricity. However, through investments in renewable energy, it achieved carbon neutrality in its operations – a benchmark that many data centre operators are yet to achieve.

2. Network Infrastructure

The internet is not just data centres, it’s also a vast network of fibre-optic cables, cellular towers, Wi-Fi routers, and satellite systems that transmit data across the globe. Each of these network elements has its own energy demand:

• Transmission Energy: According to the IEA, global internet traffic is growing at an annual rate of 25-30%, driven by video streaming, cloud computing, and emerging technologies like artificial intelligence. As traffic increases, so does the energy consumed by network infrastructure.
• 5G Rollout: While 5G networks are designed to be more efficient per unit of data transmitted, their higher speeds and increased number of connected devices mean that overall energy use is expected to rise. By 2030, 5G networks could account for 1-2% of global electricity demand.
• Undersea Cables: The global network of undersea cables, which carry over 99% of international data traffic, is maintained by energy-intensive ships and requires constant upgrades – all of which add to the carbon footprint.

3. User Devices: Billions of Power-Hungry Connections

The final part of the internet’s carbon footprint comes from the billions of connected devices – smartphones, laptops, tablets, smart TVs, and the ever-growing ecosystem of IoT (Internet of Things) devices. Each device has a twofold impact:

• Manufacturing Emissions: Producing digital devices is a resource-intensive process. The manufacture of a typical smartphone, for example, is estimated to generate around 60 kg of CO₂ – and this is before it is ever switched on. For laptops, the figure can be much higher.
• Energy Use: Once connected, these devices consume electricity. Charging a smartphone may seem like a minor impact, but with an estimated 6.8 billion smartphone users worldwide (Statista, 2023), the collective energy use is substantial. A single user streaming one hour of Netflix per day can generate around 440 kg of CO₂ per year – comparable to driving a small petrol car for 1,500 km.
• E-Waste: When devices reach the end of their life, improper disposal can lead to further emissions. In 2022, the world generated an estimated 53.6 million metric tonnes of electronic waste, much of which was not properly recycled.

How Does the Internet’s Carbon Footprint Compare with Other Industries?

To fully appreciate the impact of the internet, it helps to compare its emissions with other industries:

• Aviation Industry: Before the pandemic, global aviation accounted for around 2.5% of global CO₂ emissions. Despite the industry’s high profile, the internet’s emissions are now estimated to be higher, especially when considering the full lifecycle of digital devices.
• Automotive Industry: The global automotive sector, including emissions from vehicle manufacturing, fuel consumption, and supply chain activities, is responsible for approximately 10% of global CO₂ emissions. The internet is not yet at this scale, but its emissions are growing rapidly.
• Steel and Cement Industries: These heavy industries are among the largest industrial carbon emitters, responsible for around 7% and 8% of global CO₂ emissions, respectively. Yet as digital demand continues to grow, the internet’s emissions could one day rival these sectors.

Why Are Digital Emissions Growing So Rapidly?

The carbon footprint of the internet is not static, it’s growing. Several key factors are driving this increase:

• Video Streaming Explosion: High-definition and 4K video streaming are some of the most data-intensive activities. In 2022, online video accounted for approximately 82% of all internet traffic (Cisco). The higher the resolution, the greater the energy consumption.
• Cloud Computing Expansion: Businesses and individuals are increasingly relying on cloud services, which depend on energy-hungry data centres. Global cloud computing traffic is expected to exceed 20 zettabytes by 2025.
• Artificial Intelligence: AI systems, especially large-scale models, require vast computational power. Training a single large AI model can generate as much CO₂ as five cars over their entire lifetimes.
• 5G and IoT Growth: The rapid expansion of 5G networks and the proliferation of IoT devices are connecting billions of new devices, each adding to the overall energy demand.

How Can We Reduce the Carbon Footprint of the Internet?

Tackling the carbon footprint of the internet requires action across the entire digital ecosystem:

• Energy-Efficient Data Centres: Companies must invest in energy-efficient cooling, server optimisation, and renewable energy. Google, Microsoft, and Amazon have all committed to 100% renewable energy for their data centres, setting a benchmark for the industry.
• Sustainable Network Management: Optimising data transmission routes, using more efficient network hardware, and minimising redundant data storage can reduce energy consumption.
• User Awareness: Users can make a difference by reducing unnecessary cloud storage, streaming in lower resolution, and extending the life of digital devices.
• Circular Economy for Devices: Extending the lifespan of devices, encouraging repairs, and improving e-waste recycling can cut emissions.
• Regulatory Support: Governments can support low-carbon digital infrastructure, promote renewable energy adoption, and enforce e-waste recycling standards.

A Digital World with a Carbon Cost

The internet is not a carbon-free space. It is an expansive and energy-hungry ecosystem that, if left unchecked, could become one of our largest contributors to global emissions. But this outcome is not inevitable. By understanding where digital emissions arise and taking targeted action, we can ensure that the digital world supports, rather than undermines our journey to net zero.

Alan Stenson, CEO

Neutral Carbon Zone