CERN publishes its 4th Environment Report, which showcases concrete steps towards a sustainable future in scientific research.

Covering 2023 and 2024, the report details how CERN is maintaining its course towards environmentally responsible and sustainable science while achieving milestones such as the LHC’s highest-ever integrated luminosity. This achievement demonstrated the increasing energy efficiency of CERN’s accelerator complex in terms of data delivered per unit of energy consumed. Two other concrete steps taken in 2023 and 2024 were the inauguration of an energy-efficient data centre (with a target power usage effectiveness (PUE)[1] of 1.1),which is equipped with a heat-recovery system, and CERN’s obtention of the ISO 50001 energy management certification.

In 2024, CERN’s Enlarged Directorate approved an updated set of environmental objectives covering the period up to 2030, notably committing CERN to:

• limiting electricity consumption to 1.5 TWh/year during Run 4 of the Large Hadron Collider (LHC), despite a significant increase in physics output;
• reducing direct CO₂-equivalent emissions by 50% compared to 2018 levels, helped by reducing gas consumption by 60%;
• improving the quality of CERN’s effluent water, increasing the on-site water retention capacity and limiting water consumption;
• increasing biodiversity on CERN’s sites by enhancing local ecosystems and addressing urban heat islands in planning for the future;
• strengthening waste management and noise control actions.

This report outlines CERN’s next scientific phases. The High-Luminosity LHC, an upgraded version of the current LHC scheduled to start in 2030, is an example of CERN’s long-term vision for sustainable high-energy physics, providing a platform for the development of new, more sustainable accelerator technologies, such as two-quadrant power converters and superconductivity. Limiting environmental impact and harnessing technologies for society are also key priorities in the planning for CERN’s next flagship project that is currently being studied.

“Science should not just address global challenges but should act locally,” said Benoît Delille, Head of the Occupational Health and Safety and Environmental Protection Unit. “Our scientific goals go hand in hand with our commitment to respecting the planet. CERN can and must continue to protect the world we all share while pushing back the frontiers of knowledge.”

With this report, CERN reiterates its commitment to transitioning towards a broader sustainability reporting framework integrating environmental, social and governance (ESG) dimensions and reinforcing its ambition to serve as a role model for sustainable research.

Read more: https://environmentreports.web.cern.ch/environment-report-2023-2024/

A pdf version is available at this link: https://doi.org/10.25325/CERN-Environment-2025-004