The Carbon Footprint of Cloud Storage

Your phone’s photo backup seems weightless. Cloud storage is often described as intangible, but it relies on physical infrastructure: data is stored in large data centers that operate continuously and require electricity for servers and cooling systems. As the use of cloud services expands, the energy demand associated with storing and transferring data is increasing.

Data centers consumed about 1.5% of global electricity in 2024, and this share is projected to rise significantly by 2030 as demand for artificial intelligence grows. Furthermore, data transmission networks such as mobile and fixed-line networks account for roughly 1-1.5% of global electricity use. Together, these systems account for a growing share of global energy consumption associated with digital activity.

The carbon footprint of cloud storage is also influenced by the location of the data centers and the type of power they use. Centers using fossil fuels have a larger footprint than those using renewable energy sources. Globally, fossil fuels still supply about 60% of the electricity consumed by data centers, while renewables account for roughly 27% of their power today. The type of storage is also a factor in the use of cloud storage. The cloud storage providers usually maintain multiple copies of the data in different locations to ensure the data is not lost.

The amount of emissions that result from data storage varies depending on various methodologies. For instance, storing 1 TB of data for a year results in 25kg of CO2 emissions, although this may vary depending on the efficiency of the data center. Therefore, if we consider this approximation, 100 GB would be equivalent to 2.5kg of CO2 emissions. Although this may seem like a small amount, given that these emissions apply to only one user, the overall electricity used to support millions of users would be far greater. For instance, most cloud storage services result from digital activities such as automated backups, storing high-resolution photos and videos, and retaining unused files. These activities, in themselves, do not produce carbon emissions, but they increase the overall amount of data that is stored. 

From a net-zero perspective, emissions reduction from cloud storage is largely dependent on systemic change.  So when your phone backs up photos to the cloud, the environmental impact lies in improving data center efficiency or reducing carbon intensity in the electricity supply. Although there is scope for individual actions to influence demand, the most significant emissions reduction potential will come from decarbonizing energy supply or improving data center efficiency rather than merely individual storage choices. Such a point highlights the necessity for data centers to expand their use of renewable energy and lead a departure from fossil fuels, as demand for technology use continues to rise.