The carbon we generate by doing digital preservation has a real impact on our environment. Even 1 tonne of carbon causes polar ice to melt, and estimates are that between 640 and 2600 trees would need to be planted to offset this, but a more effective response than offsetting is to actively reduce your carbon footprint.
In order to decrease your carbon footprint, it is helpful to set targets, and to review whether, and how, you achieve them. Measuring your carbon footprint and benchmarking with similar organizations ideally should be an iterative part of your strategic planning process.
Here are some ideas of potential ways to reduce your carbon footprint:
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Change to a more carbon-neutral energy source or tariff.
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If appropriate, consider where your cloud data is stored. Regions with a high green energy component in their grid electricity will produce less carbon for the same storage than a region with a lower green energy component. You can track real-time electricity data worldwide at Electricity Maps – this is an interesting visual representation of regional differences, and it is updated every 15 minutes.
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Replace older processes and workflows with more efficient ones.
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When it becomes necessary to migrate to new storage, select storage with high sustainability standards (for example that consumes less energy or water, generates less heat, or where heat is captured and recycled for other uses).
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Schedule fixity checks during off-peak energy and network hours.
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Extend your hardware life cycle, or recycle or reuse old machines.
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Update your preservation policy (and other relevant policies) to reflect sustainability goals (for example you may introduce a policy that certain types of collections are stored on more sustainable storage).
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Review documentation and workflows with sustainability in mind. Consider whether any of the actions below are appropriate for your collections:
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Appraise your collections, be selective, and delete material in line with your retention policy (see myth 8 in Myths and Legends).
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Review the number of copies you preserve and consider whether this can be reduced.
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Deduplicate and compress data where appropriate - note that some savings can be made without data loss using lossless forms of compression.
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Decrease frequency of web archive captures or digital file transfers where appropriate.
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Review your current use of file formats and storage media and understand their impacts on your carbon footprint.
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Consider whether and when you will normalize or migrate file formats.
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Assess each cloud service provider’s carbon footprint as a whole when choosing a provider:
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Do they report on their own carbon emissions?
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Do they separate this into operational and embodied emissions?
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Will they be able to deliver information about the carbon emissions of your use of their service specifically?
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Do they use low carbon renewable power purchase agreements, or specific renewable energy purchases?
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Do they have policies around waste and recycling?
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Take reduction targets into account during procurement exercises. When procuring cloud-based preservation systems and services, ensure that the storage system is documented and that carbon emissions can be measured and reported on (again, it is worth asking the question whether they will be able to provide information related to your use of the service specifically).
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Manage your users. Making preserved data easily discoverable and reusable is a core goal, but it can have unintended environmental consequences if data is downloaded, analysed, or stored unnecessarily.
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Consider user guidance about the carbon footprint impact of different file formats.
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Remove unnecessary images from your user interfaces.
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Limit the number of search results that are returned to users.
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Provide carbon impact indicators (e.g., ‘Estimated download impact: 0.5 kg CO₂’).
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Encourage in-situ analysis.
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Implement usage throttling (for example, limiting the speed at which data is shared across a network) or tiered access.
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Measure and understand your carbon footprint (using this toolkit and the Carbon Footprint Calculation Tool for example). This will help you see the areas of activity that generate the most carbon and thus provide insights into the areas where reductions may lead to the greatest impact. For example, if organizational travel for digital preservation purposes, generates the highest carbon footprint, then making some savings here, may be an impactful first step.
Note that as of March 2026 the NDSA Levels of Preservation now includes a leaf icon to illustrate those areas within the matrix where environmental sustainability considerations may influence and inform digital preservation decisions. Further information relating to these decision points can be found within the NDSA’s Environmental Sustainability Guide.
A note about offsetting
Some organizations use carbon offsetting as a means of reducing their impact. Carbon offsetting is about balancing, compensating, or neutralising the carbon emissions from a given activity by paying into a scheme or project that will reduce emissions (for example a tree planting scheme). There are various schemes accredited under the Gold Standard or the Verified Carbon Standard (VCS) which are international certification frameworks for carbon-offset projects. They aim to ensure that carbon credits represent real, measurable, and verifiable reductions or removals of greenhouse gas emissions.
Other organizations reject carbon offsetting entirely, arguing that it delays climate action and lacks credibility and impact (see for example a joint statement from the Environmental Coalition on Standards). It is widely recognized that reducing our carbon footprint shouldn’t be done purely by offsetting and that organizations should focus on reducing their own emissions as their first priority (see for example Net Zero-Aligned Offsetting Principles).
In short, the most impactful way an organization can reduce their carbon footprint is by understanding their carbon emissions and taking steps to reduce them.