Virtual course
Byte-sized green computing
The environmental impact of computing is an increasingly important and recognised issue: growing demand for digital services, data storage, high-performance computing and Artifical Intelligence (AI) brings greater resource use (energy, water, metals, etc.) and associated impacts such as greenhouse gas emissions.
Although public awareness is growing, and active work is done by research institutions in implementing sustainability into their policy, at an individual level it can often be difficult to translate this problem into smaller, practical actions that we can take in our day-to-day work.
This series of “byte-sized” training events will offer four tailored sessions focused on practical actions that participants can implement in their work to monitor, minimise and report its environmental impact.
- Green continuous integration and continuous deployment (CI/CD)
- Metrics for monitoring software emissions efficiency
- CATS: the Climate Aware Task Scheduler
- nf-co2footprint: estimating the carbon footprint of Nextflow pipelines
All sessions will run independently, and consist of an introductory lecture followed by hands-on tutorial. The introductory lecture will be recorded, and repurposed on-demand on the EMBL-EBI Training website.
We recommend watching the “The environmental impacts of scientific computing” webinar prior to the event(s), as it provides a general introduction to sustainable computing and helps placing the sessions into context.
For more details on the programme and how to register, browse to the “Programme” and “How to apply” tabs.
Funders
The organisation of this event is supported by Wellcome Trust (Green Algorithms Initiative), the University of Cambridge, NetDRIVE and the STEP-UP project.
Who is this course for?
This course is suitable for:
- Anyone interested in sustainable software, green computing, and reducing the environmental impact of technology.
- Anyone who wants to make more informed and sustainable choices about how they use computing resources.
- Anyone who conducts computationally intensive research or works with large datasets, simulations, AI, or high-performance computing.
- Anyone who develops, manages, supports, or relies on software, digital technologies, data, or research computing infrastructure.
Learning outcomes
At the end of this course you will be able to:
- Explain the principles of Green Computing and identify ways to reduce the environmental impact of software and IT infrastructure.
- Apply sustainable practices in CI/CD pipelines to measure, monitor, and reduce the environmental impact of software delivery.
- Calculate and interpret Software Carbon Intensity (SCI) to assess the carbon impact of software systems and identify areas for improvement.
- Apply carbon-aware approaches such as CATS to incorporate carbon considerations.
- Configure GitHub Actions CI/CD workflows using best practices that minimise unnecessary computational and environmental costs.
Trainers
Josua Carl
Quantitative Biology Center (QBiC) Joseph G. Wallwork
University of Cambridge Colin Sauze
National Oceanography Centre (NOC) Andrew Turner
EPCC, University of Edinburgh Nadja Volkmann
Quantitative Biology Center (QBiC)
Programme
The programme is detailed below. All times are in GMT.
Date
Time
Session
Speaker
2 November 2026
14:00 – 15:30
Green continuous integration and continuous deployment (CI/CD)
Joseph G. Wallwork
9 November 2026
13:00 – 14:30
Metrics for monitoring software emissions efficiency
Andrew Turner
16 November 2026
14:00 – 15:30
CATS: the Climate Aware Task Scheduler
Colin Sauze
30 November 2026
14:00 – 15:30
nf-co2footprint: estimating the carbon footprint of Nextflow pipelines
Nadja Volkmann and Josua Carl
Green continuous integration and continuous deployment (CI/CD)
Continuous integration and continuous deployment (CI/CD) workflows allow testing workflows, website deployments, and much more to be automated. It is good software engineering practice to set up such workflows to avoid manual effort. However, such workflows come with a computational cost and hence an associated environmental cost. Naive configuration can lead to unnecessary triggering of workflows and therefore unnecessary carbon emissions. This session will introduce how to configure CI/CD with GitHub Actions and walk through several best practices for configuring them in an environmentally responsible manner.
Requirements: experience with git, GitHub (with an account), and the command line. Python package https://copier.readthedocs.io/en/stable/, and any Python version that supports it.
Metrics for monitoring software emissions efficiency
How do we monitor emissions efficiency and evaluate choices to improve emissions efficiency as part of our commitment to responsible computing? In this session, I will briefly introduce a family of related metrics derived from the Software Carbon Intensity metric from the Green Software Foundation. Using these metrics can provide the basis for a quantitative understanding of emissions efficiency from the use of digital research infrastructure.
CATS: the Climate Aware Task Scheduler
Many power grids experience dramatic shifts in carbon intensity due to the presence of intermittent renewable energy sources. CATS schedules computational jobs to run when the predicted carbon intensity of running them will be lowest. It was originally developed for managing single jobs using the simple "at" scheduler supplied with most Unix systems, but has since been modified to work with Slurm and to consider the effects of rescheduling multiple jobs. It can use carbon intensity forecasts from many providers, including carbonintensity.org.uk and WattNet.
Requirements: Python 3.11+ installed. For the hands-on session, a Linux/Mac machine (or a connection to a Linux server). Windows users will still be able to follow the demo but may not be able to reproduce it fully on their machine.
Geographical location: please note that CATS currently works for European geographical locations. However, attendees from other locations are still welcome to join the session if interested in CATS.
nf-co2footprint: estimating the carbon footprint of Nextflow pipelines
Computational research, including bioinformatics, increasingly contributes to greenhouse gas emissions. This talk introduces nf-co2footprint, a plugin for the workflow manager Nextflow that estimates the energy consumption and CO₂e emissions of pipeline runs. We will present its implementation, including how emissions are estimated for each pipeline step from resource usage, hardware power draw and regional carbon intensity, and share insights from benchmarking against hardware-level power measurements. Finally, we will look at the output files it produces: an interactive HTML report, a per-step trace file and a machine-readable provenance file. The talk will be followed by a guided tutorial on using and configuring the plugin.
Requirements: Nextflow version compatible with nf-co2footprint v1.4.0 installed (see https://nextflow-io.github.io/nf-co2footprint/usage/configuration/#version-compatibility).
Each event will run independently, and interested participants will have to register for each event they would like to attend.
Registration is free but limited, and places will be assigned on a first come, first served basis. Follow the “Register” button to access the registrations form.
Please note that the introductory lecture of each session will be recorded. During the recording, participants will be asked to keep their microphone and camera off. The Q&A and hands-on tutorial will not be recorded.
Please note that certificates of attendance will not be issued for the sessions.
Quantitative Biology Center (QBiC)
University of Cambridge
National Oceanography Centre (NOC)
EPCC, University of Edinburgh
Quantitative Biology Center (QBiC)
Programme
The programme is detailed below. All times are in GMT.
Date | Time | Session | Speaker |
|---|---|---|---|
2 November 2026 | 14:00 – 15:30 | Green continuous integration and continuous deployment (CI/CD) | Joseph G. Wallwork |
9 November 2026 | 13:00 – 14:30 | Metrics for monitoring software emissions efficiency | Andrew Turner |
16 November 2026 | 14:00 – 15:30 | CATS: the Climate Aware Task Scheduler | Colin Sauze |
30 November 2026 | 14:00 – 15:30 | nf-co2footprint: estimating the carbon footprint of Nextflow pipelines | Nadja Volkmann and Josua Carl |
Green continuous integration and continuous deployment (CI/CD)
Continuous integration and continuous deployment (CI/CD) workflows allow testing workflows, website deployments, and much more to be automated. It is good software engineering practice to set up such workflows to avoid manual effort. However, such workflows come with a computational cost and hence an associated environmental cost. Naive configuration can lead to unnecessary triggering of workflows and therefore unnecessary carbon emissions. This session will introduce how to configure CI/CD with GitHub Actions and walk through several best practices for configuring them in an environmentally responsible manner.
Requirements: experience with git, GitHub (with an account), and the command line. Python package https://copier.readthedocs.io/en/stable/, and any Python version that supports it.
Metrics for monitoring software emissions efficiency
How do we monitor emissions efficiency and evaluate choices to improve emissions efficiency as part of our commitment to responsible computing? In this session, I will briefly introduce a family of related metrics derived from the Software Carbon Intensity metric from the Green Software Foundation. Using these metrics can provide the basis for a quantitative understanding of emissions efficiency from the use of digital research infrastructure.
CATS: the Climate Aware Task Scheduler
Many power grids experience dramatic shifts in carbon intensity due to the presence of intermittent renewable energy sources. CATS schedules computational jobs to run when the predicted carbon intensity of running them will be lowest. It was originally developed for managing single jobs using the simple "at" scheduler supplied with most Unix systems, but has since been modified to work with Slurm and to consider the effects of rescheduling multiple jobs. It can use carbon intensity forecasts from many providers, including carbonintensity.org.uk and WattNet.
Requirements: Python 3.11+ installed. For the hands-on session, a Linux/Mac machine (or a connection to a Linux server). Windows users will still be able to follow the demo but may not be able to reproduce it fully on their machine.
Geographical location: please note that CATS currently works for European geographical locations. However, attendees from other locations are still welcome to join the session if interested in CATS.
nf-co2footprint: estimating the carbon footprint of Nextflow pipelines
Computational research, including bioinformatics, increasingly contributes to greenhouse gas emissions. This talk introduces nf-co2footprint, a plugin for the workflow manager Nextflow that estimates the energy consumption and CO₂e emissions of pipeline runs. We will present its implementation, including how emissions are estimated for each pipeline step from resource usage, hardware power draw and regional carbon intensity, and share insights from benchmarking against hardware-level power measurements. Finally, we will look at the output files it produces: an interactive HTML report, a per-step trace file and a machine-readable provenance file. The talk will be followed by a guided tutorial on using and configuring the plugin.
Requirements: Nextflow version compatible with nf-co2footprint v1.4.0 installed (see https://nextflow-io.github.io/nf-co2footprint/usage/configuration/#version-compatibility).
Each event will run independently, and interested participants will have to register for each event they would like to attend.
Registration is free but limited, and places will be assigned on a first come, first served basis. Follow the “Register” button to access the registrations form.
Please note that the introductory lecture of each session will be recorded. During the recording, participants will be asked to keep their microphone and camera off. The Q&A and hands-on tutorial will not be recorded.
Please note that certificates of attendance will not be issued for the sessions.