Alright, Let's Get Into This! Understanding the Internet Infrastructure and Its Ecological Impact

In our everyday life, the internet often feels weightless - just a signal on a screen. But beneath this usability is a complex and energy-intensive infrastructure. This backbone of the digital economy is both intangible in user experience and concrete in its material and environmental presence. 

The internet infrastructure is a vast system of hardware, software, and protocols that work together to connect billions of devices across the globe.

It can be broken down into three primary categories:

a.) the physical infrastructure that includes fibre optic cables, including undersea cables, routers, servers, data centres, and satellites;

b.) the logical infrastructure that includes protocols, which are the rules and standards that govern how data is transmitted between devices; and

c.) the software infrastructure that governs how devices and programs interact. 

Three Layers of the Internet Infrastructure

In this piece, we look at the environmental footprint of the physical infrastructure – the data centres and fibre optics, including the undersea cables. 

How Does This System Work? 

When you hit play on a streaming video or open a document stored on the cloud, your action triggers a chain of physical events: electricity flows into a data centre, servers process the request, packets of data travel across networks, and sometimes beneath the ocean to reach you. Each link in that chain consumes energy, uses materials, and has a series of environmental impacts. Let us understand this in detail.

The internet infrastructure is a vast, layered global network of interconnected systems, comprising both physical hardware and logical protocols, designed to facilitate worldwide data communication. 

How Does This Network Work in Everyday Life? 

Everyday Working of the Internet

The physical layer, often called the Internet Backbone, includes high-capacity fibre optic cables, including the ones laid under oceans, routers and switches that direct traffic, data centres housing powerful servers, and Internet Service Providers (ISPs) that connect end users. When you send a request, like clicking a link, your data is first broken down into small units called packets. Each packet is tagged with the destination's IP address and then travels from your local network through your ISP and into the network of high-speed fibre optic cables that connect countries around the world. Routers use routing tables and protocols like IP and TCP (Transmission Control Protocol) to determine the quickest path for each packet across the network of networks. The Domain Name System (DNS) is the logical layer service that translates human-readable web addresses (like https://www.google.com) into the necessary IP addresses. Upon reaching the destination server, the packets are verified, reassembled in the correct order by TCP, and the requested information is sent back through the same infrastructure to your device, reassembling the final data (like a webpage) for you to view. All of this typically happens in milliseconds. 

Throughout this process, TCP/IP protocols ensure data integrity and correct sequencing, encryption secures information, and redundancy keeps the network resilient.

The Data Centre Footprint

The environmental impact of data centres is multifaceted, primarily revolving around high consumption of energy and water, as well as the generation of electronic waste.

According to the International Energy Agency (IEA), in 2024, global electricity consumption by data centres was around 415 terawatt-hours (TWh), representing about 1.5% of global electricity use. The IEA projects consumption could more than double to around 945 TWh by 2030, taking the share to near 3% in a base case. That may still be a small amount compared with the global electricity demand, but locally, the impact is significant. Data centre clusters concentrate in regions with very high power loads and comparatively simpler regulations. This creates an imbalance. 

Below is an image showing the typical working and infrastructure of a data centre. 

Image Source: https://www.iea.org/reports/energy-and-ai/energy-demand-from-ai 

Along with the data centres, data transmission networks^[i] also consume significant electricity. In 2022, these consumed 260-360 TWh, which is about 1-1.5% of global electricity. It has been observed that mobile networks make up roughly two-thirds of this network energy; fibre/Wifi is generally a greener way to move heavy data than 4G/5G. Interestingly, it is to be noted that estimates vary a lot. Researchers have found that global ICT energy figures can diverge by factors due to different scopes, methods, and availability of data. This means that we must treat any single number cautiously, as methodology matters. However, such estimates help put our interaction with the internet into context. 

Understanding these perspectives is important to have an informed dialogue and counter pessimistic views regarding one’s digital footprint.

Life Cycle Thinking: It is Not Just Electricity

When we talk about internet emissions, we often focus on the use phase of electricity. But life cycle impacts - the materials, manufacturing, installation, maintenance, and end-of-life must be accounted for as well. Studies have shown that most ICT network emissions come from devices, not operations. Around 70 - 80% of the total carbon footprint of 4G LTE networks is embodied in user devices (mainly smartphones), while only 20 - 30% arises from electricity use in operation. Further, rural networks have higher per-user footprints. Because network equipment is shared by fewer subscribers, rural and remote areas show higher carbon emissions per subscription or gigabyte.

Water Use by Data Centres 

Data centres require vast amounts of chilled water to cool overheating servers. This necessity creates significant strain on local water supplies, particularly in drought prone regions. It has been estimated that, for each kilowatt hour of energy a data centre consumes, it may require up to two litres of water for cooling. Further, data centre set up is not uniform across the globe. Most data centres are located in water stressed regions because these areas offer less land and labour cost, strong digital infrastructure, and proximity to growing markets, despite their limited water resources. This leads to uneven impact on communities and their resources. 

Artificial Intelligence (AI) forms a major part of our internet interactions nowadays. Literature has suggested that by 2027, the global water withdrawal for AI, primarily driven by data centres, is estimated to reach between 4.2 and 6.6 billion cubic meters annually. This has been regarded as more than two-thirds of England’s annual water consumption. 

There is a vast difference between global data centre electricity and water consumption pre- AI boom (2015-2019) and post and current AI boom (2024-2025).

Data Centres Need Water to Cool Servers

Electronic Waste by Data Centres 

Electronic waste from data centres stems from the rapid obsolescence and frequent upgrades of servers, storage devices, networking gear, and power infrastructure required to meet ever increasing demands for data processing and storage. As hardware reaches its end of life, often due to technological advancements rather than failure, it contributes significant volumes of discarded equipment containing valuable materials like gold, palladium, and copper, as well as hazardous substances such as lead, mercury, and cadmium. Improper disposal or insufficient recycling of this specialized IT equipment poses severe environmental risks, including the contamination of soil and water. 

It has been documented that global e-waste generation was 61.9 million metric tonnes in 2022, rising by 2.6 million tonnes annually, with a 22.3% of the actual mass documented as properly collected and recycled. Data centres contribute significantly to this issue, with 5381 centres in the US alone as of March 2024, compared to just over 500 in Germany and the UK. Further, 12% of data centres do not engage in any e-waste recycling, and 43% lack an environmental policy for dealing with it. 

Data Centres Generate E-waste

So What Can We Do About It?

Traditional recycling, which breaks down electronics for new products, is hindered by insufficient infrastructure for the sheer volume of waste. Along with this, there are issues like the presence of complex and sometimes toxic materials in the equipment, the resource-intensive process, and the lack of standardized policies. 

Did you know there have been ethical concerns surrounding illegal e-waste export that are primarily rooted in a form of environmental injustice, where developed nations offload their hazardous waste onto developing countries lacking the infrastructure to process it safely?

Given these limits and the problem of disposing of functional but out-of-date equipment, it is often argued that refurbishment and reuse, which is part of a circular economy, is a superior solution to reduce environmental impact and business expenses compared to recycling, which ultimately creates new products and perpetuates the e-waste cycle.

Fibre Optics – What Are These? Are They Sustainable? 

Now, let us look at another layer of the physical infrastructure – The Fibre Optic Cables. 

Fibre Optic Cables

Fibre optics are thin glass or plastic strands that transmit data as light, allowing information to travel very fast and efficiently over long distances. Building fibre networks requires more energy and materials than copper, leading to higher initial environmental impacts. However, once installed, they use less energy, last longer, and carry more data, so over time they offer significant environmental and performance advantages.

Let us understand this in detail. 

Fibre optic cables consume up to 70% less energy per gigabit and generate less heat, significantly reducing the cooling demands of data centres and contributing to a longer lifespan of 25+ years. They offer faster speeds and vastly greater bandwidth to transfer data without requiring more frequent and power-consuming signal boosters. However, their manufacturing requires silica derived from quartz sand, a process that is energy-intensive and uses extreme heat and heavy industrial energy sources. Furthermore, the cables incorporate fossil fuel-based materials like PVC and polyethylene for protective coatings. The biggest sustainability challenge is the end-of-life problem. The multi-material construction of glass, plastic, and sometimes metal makes them extremely difficult and costly to recycle, leading most waste cables to end up in landfills, unlike easily recyclable copper.

Despite these production challenges, fibre optics are deemed a considerably sustainable infrastructure. 

Undersea Cables – So Data Transfers Across the Ocean, but What About Marine Life?

Undersea Cables

Fibre optics are also set up under the sea. These are called undersea cables. These cables are thin glass fibre cores encased in protective sheaths and lie on or beneath the ocean floor, linking islands, continents and data hubs. The majority of these cables (74%) are located in shallow waters within national jurisdictions, specifically territorial seas and Exclusive Economic Zones (EEZs). Further, approximately 26% are in Areas Beyond National Jurisdiction (ABNJ).

The environmental impact of submarine fibre optic or undersea cables is generally considered minimal and localized. However, impacts do occur across the cable’s lifecycle, from installation to decommissioning.

The primary environmental pressures occur when cables are first being laid. Heavy machinery and cable-laying vessels can cause physical disturbance to the seabed, disrupting sediment layers and impacting creatures living on the seafloor. This is most pronounced in sensitive, shallow water areas like coral reefs and seagrass meadows. Along with this, trenching and burial, done near shore for protection, cause sediment resuspension^[ii] and noise pollution, which can temporarily disrupt marine life. Globally, the overall impact is considered minor, as less than 0.01% of the seafloor is within 10 meters of submarine cables.

Once installed, fibre optic communication cables typically have minimal long-term effects on the environment. The cables themselves are generally chemically inert^[iii] and, when laid on the deep sea floor, are often found to have little or no impact on the resident fauna and flora. Further, in some areas, surface-laid cables can act as artificial reefs, which become habitat for some organisms with properties such that they might be more abundant near the cable than in undisturbed areas. In fact, undersea cables transmit data using light, not electricity, so they only carry small currents to power signal amplifiers. This produces very low electromagnetic fields (EMFs) and minimal heat. In contrast, high-voltage subsea power cables^[iv] generate much stronger EMFs that can affect electro-sensitive marine species like sharks and rays. 

Decommissioning and Disposal

When a cable reaches the end of its typical 25-year lifespan, decisions must be made about its removal.

Remove the Cable, Recycle It, or Let It Be?

Please note that not enough credible data is available in this regard. Some say that some cables may last much longer, up to 40 years or more, and some may last up to 15 to 17 years; decisions must be made about their removal.

There is a crucial trade-off between removing out-of-service cables, which requires invasive operations that can cause new environmental damage, and leaving them in place. Out-of-service cables are increasingly viewed not as waste, but as valuable materials (like copper and plastics) that can be recovered and recycled. However, understanding the feasibility of this requires a cost-benefit analysis as well as exploring its further impact on marine life. This is an area where more research is suggested.

There is significant research potential within undersea cables. For instance, cables offer an opportunity to enhance marine biodiversity knowledge through integrated sensing technologies (detecting seismic activity, temperature, pressure, and noise). These can help fill existing data gaps in ocean monitoring, and more research on this is warranted. It is also useful to see whether regulations surrounding multi-use cables – that combine telecommunications and scientific research functions could be harmonised across jurisdictions. Lastly, establishing cable protection zones where damaging activities like trawling are prohibited has the potential to support biodiversity conservation and recovery. 

Concluding Remarks

The internet infrastructure offers invisible convenience but visible materiality. On one hand, digital services feel free and weightless; on the other, the reality is grounded - data centres, cables laid beneath oceans, high electricity and water usage, disposal of e-waste, impact on marine life, as well as the everyday impact on us humans. Growth in digital services must be accompanied by smarter planning, materials thinking, ecological awareness, and resilience. That being said, this onus must not fall on one body; design choices, the regulatory landscape, and user habits all make a material difference.

[i] For the understanding of our readers, data transmission networks are not the same as fibre optics. Data transmission networks include all systems that move data between devices, networks, and data centres. They encompass mobile networks like 4G and 5G, fibre, Wi-Fi as well as satellites.

[ii] Sediment resuspension occurs when a physical force, such as strong currents, waves, human activity or the movement of large vessels, disturbs the seafloor. This force overcomes the gravitational pull holding the sediment down, causing the particles to mix back into the water.

[iii] A material is chemically inert if it does not easily undergo a chemical reaction with the surrounding environment, even when exposed to conditions like water, oxygen, acids, or biological matter.

[iv] Please note that subsea power cables are used to transmit electricity under the sea. For example, from offshore wind farms to the mainland, or to connect power grids between islands or countries. Whereas, undersea cables are used to transmit internet, phone, and data between continents and countries.