Key Points

Why sustainable digital research matters


  • ICT currently contributes around 4.1% of global carbon emissions, with projections reaching 14% by 2040.
  • Digital research in the UK alone generates an estimated 75 kilotons of CO₂e per year, split roughly equally between large-scale compute facilities and smaller devices.
  • Net zero goes further than carbon neutral by targeting all greenhouse gases and requiring offsets that genuinely absorb emissions rather than merely compensating elsewhere.
  • Mindful computing is a conscious approach to planning, running and managing digital tasks to ensure scientific progress does not produce more emissions than necessary.
  • Researchers have a responsibility to consider the environmental impact of their digital activities and take steps to reduce them.

Energy, power and carbon


  • Carbon intensity of electricity varies throughout the day and across the year depending on the energy mix, which is driven by demand, weather, and fuel costs.
  • Demand shifting — scheduling computationally intensive work during periods of low carbon intensity — is a practical strategy to reduce operational emissions.
  • Embodied carbon covers emissions from the full lifecycle of a product including manufacture, transport, and disposal, not just operational electricity use.
  • The GHG Protocol categorises emissions into Scope 1 (direct), Scope 2 (purchased energy), and Scope 3 (value chain), providing a framework for comprehensive accounting.
  • Taking a broad view across all three scopes avoids underestimating the true carbon footprint of digital research activities.

Digital research activities with sustainability issues


  • For consumer devices, embodied emissions typically outweigh operational emissions, making extending device lifetime the most impactful sustainability action for personal computing hardware.
  • Data centres are generally more carbon efficient than equivalent local computing setups due to higher utilisation, better cooling efficiency, and shared infrastructure.
  • Choice of storage technology significantly affects carbon emissions; LTO tape is preferable for cold or archival data, while SSDs suit frequently accessed data.
  • Research data management practices — such as deleting unused data, using compression, and adopting tiered storage — can substantially reduce storage-related emissions.
  • Generative AI emissions scale with model size, query count, and response length; selecting the smallest model appropriate to the task reduces unnecessary emissions.
  • Carbon-aware computing — shifting workloads in time or location to periods or regions with lower carbon intensity — is an effective strategy for reducing operational emissions from computational workloads.

Introduction to the Case Studies


  • Carbon emissions in digital research map to specific research roles and workflows, meaning reduction strategies need to be tailored to context.
  • Identifying and quantifying emissions is the essential first step before designing effective reduction measures.
  • Different research roles face distinct sustainability challenges; insights from one context may still be transferable to others.

Case Study 1 - Research Software Engineer


  • Research software development can have significant environmental impacts.
  • Measuring and estimating carbon emissions from research software development is important for identifying areas for improvement.
  • GitHub Actions and LLMs should be used judiciously to avoid unnecessary emissions.
  • Performance profiling can be a useful tool for identifying areas of code that could be optimised to reduce emissions.
  • Providing good user documentation and support can help users to make more efficient use of software, reducing emissions from usage.

Case Study 2 - Lab Scientist doing computational work


  • Storing large amounts of research data can have significant environmental impacts.
  • Having a good data management plan and using appropriate storage medium can reduce the carbon emissions associated with storing data.
  • Not all tasks require the most advanced LLM model. Switching from a reasoning model to a less powerful model for simple data processing and analysis scripts can also contribute to lowering carbon emission associated with digital research.
  • While Emma’s improvements are substantial, they represent only one piece of a larger puzzle. For a life scientist, the total work-related emissions typically range from 4 to 15 tCO2e annually 2. These numbers are driven by carbon intensive activities, such as international travel, laboratory heating, ventilation and AC systems, and the heavy use of chemical reagents and single-use equipment.
  • Data storage is often the dominant source of carbon emissions for researchers working with large datasets and long retention requirements.
  • Adopting a tiered storage strategy — using LTO tape for archival data and HDDs or SSDs for actively accessed data — can reduce storage emissions by an order of magnitude.
  • Choosing a smaller, task-appropriate LLM model can reduce AI inference emissions dramatically compared with using the largest available model.
  • Defining a data management plan before a project begins helps avoid unnecessary data collection, replication, and long-term storage.
  • Contextualising digital emissions alongside other research activities such as lab equipment and travel helps identify where reductions will have the greatest impact.

Case Study 3 - HPC User


  • Tracking actual resource usage across HPC facilities is essential before attempting to measure or reduce associated emissions.
  • Wasted computation from failed or misconfigured jobs is a significant and avoidable source of emissions; validating job inputs before submission reduces this waste.
  • Different HPC clusters vary in carbon efficiency; benchmarking workloads across available facilities helps identify where to direct them for lowest impact.
  • Benchmarking parallel job resource allocation can reveal configurations that reduce energy use with only a modest speed penalty.
  • Sharing findings on emissions and efficiency with colleagues and facility operators multiplies the impact of individual actions across a research community.

Case Study 4 - GPU Computing User


  • Prior training run data and local benchmark timings can be combined to estimate emissions before committing to an expensive full training run.
  • Naive ML training workflows often contain significant avoidable computation — training from scratch when transfer learning is possible is a common and costly example.
  • ML-specific optimisations (transfer learning, early stopping, mixed precision, model pruning) can reduce both training time and GPU memory requirements, often by an order of magnitude.
  • Maximising GPU utilisation through right-sized batch sizes improves energy efficiency; a partially-occupied GPU is disproportionately less efficient than a fully-occupied one.
  • Cloud training offers lower operational carbon through data centre efficiency but removes the option to demand-shift; local training restores that flexibility at the cost of higher embodied emissions per unit of compute.

Summary


  • Digital research infrastructure is a growing contributor to global carbon emissions, but individual researchers can take meaningful action to reduce their impact.
  • Measuring or estimating emissions is the critical first step before designing effective reduction strategies.
  • Many emission reduction measures align with established best practices in software engineering, data management, and research methodology, providing additional motivation for their adoption.
  • Sustainable digital research requires ongoing monitoring and adaptation as workflows, tools, and infrastructure evolve over time.