Carbon Footprint of the Internet

2-4%of global CO2from ICT

Global avgData centres + networks + devices

This figure is a global average from peer-reviewed research. Actual values vary by country due to differences in energy grids, farming practices, and supply chains. Use our calculators for country-specific estimates.

Key Takeaway

The information and communications technology (ICT) sector — encompassing data centres, telecommunications networks, and end-user devices — produces an estimated 2-4% of global greenhouse gas emissions, roughly comparable to the aviation industry. Global internet traffic has grown over 25-fold since 2010, yet emissions have grown more slowly thanks to dramatic efficiency improvements in servers, networks, and cooling systems.

In this article

Data Centres: The Internet's Engine Room
Network Infrastructure: The Hidden Energy Consumer
Devices: The Largest but Least Visible Component
How to Reduce Your Internet Carbon Footprint
Frequently Asked Questions

Data Centres: The Internet's Engine Room

Data centres consume approximately 1-1.5% of global electricity — roughly 300-350 TWh per year. These facilities house millions of servers that power websites, cloud computing, streaming services, social media, e-commerce, and enterprise applications. Energy is consumed both by the computing equipment itself and by cooling systems that prevent servers from overheating — cooling typically accounts for 30-40% of total data centre energy use. Power Usage Effectiveness (PUE) measures data centre efficiency: a PUE of 2.0 means the facility uses twice as much total energy as the IT equipment alone, with the excess going to cooling and overhead. Leading hyperscale operators like Google, Microsoft, and Amazon have driven average PUE below 1.2 through innovations such as liquid cooling, free-air cooling in cold climates, and hot/cold aisle containment. Smaller colocation and enterprise data centres often have PUE of 1.5-2.0, representing significant efficiency improvement opportunities.

Network Infrastructure: The Hidden Energy Consumer

Telecommunications networks — including fibre optic cables, mobile base stations, routers, and switches — consume roughly 250-300 TWh of electricity per year globally. Mobile networks are particularly energy-intensive: a single 5G base station consumes 2-4 times more power than a 4G station, and the rollout of 5G is driving significant network energy growth. However, 5G is far more energy-efficient per gigabyte of data transmitted due to higher throughput. Fixed broadband (fibre, cable, DSL) uses roughly 0.001-0.01 kWh per GB, while mobile networks use 0.05-0.1 kWh per GB — making mobile data 5-100 times more energy-intensive per GB than fixed connections. Subsea cable networks that carry 97% of intercontinental data are relatively efficient, using the electricity equivalent of a small town to transfer enormous volumes of data across oceans. The transition from copper to fibre-optic last-mile connections reduces network energy consumption by roughly 80% per connection.

Devices: The Largest but Least Visible Component

End-user devices — smartphones, laptops, tablets, TVs, gaming consoles, and IoT devices — are collectively the largest component of ICT emissions, accounting for roughly 50-60% of the total when manufacturing emissions are included. The manufacture of a smartphone produces approximately 50-80 kg CO2e, a laptop 300-400 kg, and a desktop computer 500-800 kg. With billions of devices being produced, used, and discarded every year, the embodied carbon in device manufacturing dominates the ICT sector's footprint. Annual device usage emissions are typically 20-50 kg CO2 for a smartphone, 30-60 kg for a laptop, and 50-120 kg for a desktop with monitor — depending on usage hours and local electricity grid intensity. The rapid device replacement cycle in consumer electronics — averaging 2-3 years for smartphones — means manufacturing emissions are continuously re-incurred, making device longevity one of the most impactful interventions for reducing ICT emissions.

How to Reduce Your Internet Carbon Footprint

Individual actions to reduce digital carbon emissions: (1) Keep devices longer — extending a smartphone from 2 to 4 years halves its annualised manufacturing footprint. (2) Use Wi-Fi instead of mobile data — Wi-Fi is roughly 5-100 times more energy-efficient per GB. (3) Choose smaller screens — a 13-inch laptop uses 5-10 times less power than a 65-inch TV for the same content. (4) Reduce cloud storage of unnecessary files — data at rest in data centres still consumes energy for storage and redundancy. (5) Unsubscribe from unwanted email newsletters — global spam and unwanted email generates an estimated 0.3% of worldwide electricity consumption. (6) Buy refurbished electronics — saves 85-90% of manufacturing emissions. At a systemic level, the most important developments are renewable energy procurement by major tech companies (Google, Apple, Microsoft, and Meta have all committed to 100% renewable energy for operations), improved cooling technologies, right-sizing of server infrastructure, and regulation requiring energy efficiency standards for data centres. The EU Energy Efficiency Directive now covers data centres, requiring energy audits and reporting.

Frequently Asked Questions

How much CO2 does the internet produce?

The entire ICT sector — data centres, networks, and devices — produces approximately 2-4% of global CO2 emissions, or roughly 1.5-3 billion tonnes per year. This is comparable to the aviation industry's footprint. Data centres alone account for about 1-1.5% of global electricity use.

Is the internet bad for the environment?

The internet's direct carbon footprint is significant and growing, but it also enables emissions reductions in other sectors — remote working, video conferencing replacing travel, smart energy management, and digital services replacing physical products. The net effect depends on how the efficiency gains from digitalisation compare to the energy cost of the digital infrastructure itself.

Do emails have a carbon footprint?

Yes, but it is very small. A standard text email produces roughly 0.3-4 g CO2 depending on size and whether it has attachments. A large attachment email can produce 20-50 g CO2. However, global email volume — roughly 350 billion messages per day — makes the aggregate footprint non-trivial.

Is 5G more or less efficient than 4G?

Per base station, 5G uses 2-4 times more power than 4G. However, 5G transfers data much faster, making it roughly 10 times more energy-efficient per gigabyte of data. As data demand grows, 5G's per-GB efficiency advantage becomes increasingly significant.