5 min read
In this article, we took a dive into the literature to uncover how much carbon comes from the entire lifecycle of our devices — from production to usage to disposal. Many of our findings came from a collaborative study between Harvard University and Facebook in the academic publication Chasing Carbon: The Elusive Environmental Footprint of Computing. We suggest referring to this study if you’re interested in reading further in-depth information.
How big of a toll does manufacturing a digital device have on the environment?
This 2021 study found that after breaking down the lifecycle emissions of a device — including the total emissions from manufacturing, transport use, and recycling — the majority of emissions for most products can be derived from the initial manufacturing. Over the past decade, the emissions from hardware manufacturing rose due to our increased demands on our technology. More consumer demands lead to more capabilities being implemented in our digital devices, resulting in more complex hardware, and higher carbon emissions. In fact, the percentage of lifecycle carbon emissions attributed to manufacturing went from 49% for the iPhone 3GS to 86% for the iPhone 11. Even if we compare two relatively similar products: an iPhone 11 Pro requires 66kgCO2 while a Samsung Pixel 3A requires 45kg of CO2. In this case, the iPhone requires 32% more carbon in manufacturing but achieves 73% faster image processing than the Pixel 3A.
What is worse for the environment: using a device or manufacturing it?
According to the calculations expressed in this study, it depends on your device. Digital devices that require more lifetime energy use, such as a desktop computer, will emit more carbon from using the device than manufacturing it. On average, the percentage of lifecycle carbon emissions attributed to the manufacturing process is approximately 75% for battery devices and 50% for desktop computers.
For instance, a MacBook emits an estimated 300kg of CO2 amount of carbon for its entire lifecycle — from manufacturing to disposal. About 74% of these emissions are from manufacturing, 19% from lifetime energy use, 6% from transport, and 1% from recycling. On the other hand, a Mac Pro desktop emits an estimated 3000kg of CO2 during its entire lifecycle, with 30% of emissions from manufacturing, 63% from lifetime energy use, 6% for transport, and 1% for recycling.
The above estimates assume that the device is used for 3-4 years, an average lifetime for an Apple product. If the device is used for longer than this period, the carbon emissions from using a digital device may start to outweigh the carbon emissions from the manufacturing process. Regardless, an insight here is that it may be more sustainable to use laptops rather than desktops when looking at net carbon emissions.
Revisiting data centres
It should be noted that the author’s calculations appear to use the average carbon intensity of electricity. This means that the percentage of carbon emissions that come from using a digital device will vary based on the energy source or data centre you are connected to.
Thankfully, many data centres are becoming more efficient and cutting their carbon emissions exponentially with the adoption of renewable energy sources and efficient computing. In the case of Facebook’s Prineville data centre, the annual carbon output is close to 0 through the adoption of these sustainable practices.
Facebook Prineville Energy use:
While this is a great case study, we cannot extend these findings to all data centres, nor is raw energy consumption the only indicator of how sustainable a data centre is. The Environmental Footprint of Data Centres in the United States (2021) investigated the carbon output of data centres in terms of their energy consumption, power source, and water usage. When accommodating power source and water consumption, data centres that were located in water-scarce states were exponentially more detrimental to the environment.
The carbon footprint of data centres in the USA:
Further, specific regions are more (or less) dependent on unsustainable energy sources like coal or natural gas. For instance, data centres in the central region of the United States use 10% of the entire country's energy requirements to run data centres but contribute to 30% of the country's data-centre-derived carbon emissions.
The point here is that the percentage of lifecycle carbon emissions that can be attributed to energy use or manufacturing may depend on where you are located — data that is nearly impossible to get on an individual level.
The Good News and The Bad News.
The good news here is that the carbon output of individual data centres is going down, thanks to the increased adoption of renewable resources and energy efficiency measures. The bad news, is the global carbon emissions from ICT, including the manufacturing, transporting, data centre use, and personal use of digital devices, is going up due to increased demands — more laptops, more phones, more people online, more things for a person to do online.
So, what can we do about it?
The good aspect that has come out of investigating the impact of digital hardware on the environment is that there are some straightforward ways that we can reduce our personal emissions — coming back to the classic reduce, reuse, recycle.
Reduce: Your current iPhone continuing to work makes an excellent case for not buying the iPhone 15 when it is released.
Reuse: When your phone screen cracks or keyboard breaks, consider repairing it instead of buying a new one.
Recycle: When your device finally dies, look up e-waste disposal options in your area. Throwing your technology in a landfill will certainly lead to toxic materials leaking into our environment, and could mean that reusable parts and pieces of your device end up in a landfill instead of being reused in new devices or repairs.
Understanding the technical aspects of sustainable digital design has been a journey. We want to thank the people who took the time to send us feedback and resources in response to our State of Sustainable Digital Design report. As we wade through the sea of technical information and understanding, we will be sure to keep you updated with our findings and recommendations on how we can all contribute to a better world.