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The term IT (Information Technology) has been in use since an article in the Harvard Business Review in 19581. However what people think of when they hear the term IT has changed dramatically over the years—from feeding punched cards into a mainframe computer, to a smartphone accessing services from the cloud.

When analysing greenhouse gas (GHG) emissions it’s important to be clear about the scope being discussed, so often researchers will use the formal sector definition of Information and Communication Technology2 (ICT). This sector definition states that ICT includes user devices including laptops, smartphones and tablets; networks including fixed, mobile and enterprise networks; and data centres including everything from enterprise data centres through to the large hyperscale data centres.

In addition to studying the ICT sector, researchers will often also look at the GHG emissions from the Entertainment and Media (E&M) sector, as this sector is tightly linked in the way we consume many digital services today. This E&M sector definitions includes TV’s, gaming consoles, printers, scanners, and paper media.

Both these sector definitions continue to evolve as new IT devices and services appear, such as virtual reality (VR) headsets, wearables, and smart home technologies. This continual evolution of the scope is one of the things that makes the analysis difficult and means care needs to be taken when comparing results between different researchers.

The IT industry in our everyday lives

Today we take many of these IT services for granted. The movie we watch at home on a Saturday night may start in a large data centre, stream across the internet, come into our house via a router and then be viewed on a large TV screen. Similarly at work, when we call a colleague our speech is likely to be broken into digital packets and transmitted over the same network used to access the sales systems.

New technologies continue to mature and become more pervasive, such as artificial intelligence, the Internet of Things, big data, and the cloud. Cisco amongst others publish predictions of how these technologies will change our digital experiences, change the way we work, and shape our lives.3

As IT becomes more and more pervasive in our lives, we naturally see an increasing interest and debate around its impact on greenhouse gas emissions and climate change.

How does IT contribute to emissions and climate change?

When we talk about the impact that IT has on climate change, people often refer to the carbon footprint. A carbon footprint is more than just the electricity used by a product. The carbon footprint looks at the impact across the full lifecycle of a product including acquiring the raw materials, manufacturing and shipping, electricity use in operations, and treating the product at end of life.

Most studies of the ICT sector indicate that user devices account for around half of the total carbon footprint. Breaking that down across a user devices life cycle, around half of the carbon footprint is related to the use phase, and the other half to the remainder of the life cycle. The remaining carbon footprint of ICT is split between networks and data centres as in figure 1. For these the largest part of the carbon footprint comes from the use phase.

A graph about data emissions
Figure 1. Total ICT Sector carbon footprint4

The GHG emissions from the use phase of a device depends on the energy source used to make the electricity that powers it. In some countries, or for some companies, they may use a lot of renewable energy, in which case the use phase contribution to the carbon footprint may be smaller. However even when renewable energy is being used, increasing energy efficiency is still a focus as estimates show ICT currently uses around 4% of global electricity4.

Although conclusions from different studies vary, it is estimated that the ICT sector causes between 1.5% and 4% of global GHG emissions. This is said to be the direct carbon footprint.

IT has the potential to help reduce global GHG emissions

While the direct effect of ICT increases GHG emissions, the indirect effects could lead to a decrease, or an increase. Examples where ICT could help decrease emissions are leveraging artificial intelligence to improve fuel efficiency in cars or using video conferencing to replace a business trip. Examples where it could lead to an increase in emissions (sometimes referred to as a rebound effect) are where the cost to drive a car per kilometre decreases due to the efficiency gains, so people drive longer distances, or after meeting by video conference then flying to meet in person.”

Studies of the potential of ICT to decrease GHG emissions usually either focus on one specific use case such as video conferencing, which is then studied in detail, or do an estimate across several different industry sectors like transport, buildings, or energy. This type of analysis is very complicated and while a number of studies estimate that ICT has the potential to reduce global emissions 15% by 2030, the range of estimates varies from 1.3% to 20%5.

Overall, the available published data suggests that ICT has the potential to help reduce global GHG emissions significantly, but more real-world data is needed to understand both the opportunities and the risks. Whether ICT can ultimately reduce emissions depends not only on the technology, but also our ability to master rebound effects.

Actions Cisco is taking to help reduce emissions

As a large, global company, we want to do our part to decrease the GHG emissions associated with our business and help our customers do the same. A key priority is continuing to improve the performance of our products while maintaining, or decreasing, their energy use. This allows us to tackle our direct GHG emissions and reduces global energy demand. We try this through product improvements such as more energy efficient power supplies, research into alternative methods of cooling, and next generation ASICs. We’re also giving our customers more insight into their energy usage through energy dashboards like in Cisco Nexus Dashboard, and giving them the ability to save energy by setting policies to switch off features outside of office hours like in Webex Control Hub.

In addition to helping tackle direct emissions we also look at how we can help reduce emissions in other sectors through innovations like Smart Buildings6. Lastly of course we look at how we can reduce our own emissions from our internal operations like our data centres and we share our lessons learnt so others can do the same7.

The role of IT in climate change is complicated and we recognise that as an industry we still have a lot of work to do. However, if we learn to harness the power of IT wisely, it could become a key enabler for the transition to a net zero world.

Willing to learn and engage more on environmental sustainability? In the next blog in our Sustanability 101 series, we will share more about virgin plastics.


Information regarding Cisco’s environmental, social, and governance (ESG) initiatives, goals and commitments, our latest impact, as well as policies and additional disclosures for specialized audiences, can be found in our 2022 Cisco Purpose Report and supplemental information in our ESG Reporting Hub.

  1. Management in the 1980’s” by Harold J. Leavitt and Thomas L. Whisler (HBR)
  2. Annex 1. The OECD Definition of the ICT Sector” (OECD)
  3. Tech Trends and Predictions That Will Shape 2023” (Cisco Blogs)
  4. ICT Sector Electricity Consumption and Greenhouse Gas Emissions – 2020 Outcome
  5. A review of assessments of the greenhouse gas footprint and abatement potential of information and communication technology
  6. Sustainability 101: How smart buildings help the planet and people” (Cisco Blogs)
  7. Cisco IT Data Center Sustainability