CERN Accelerating science

Air protection

At CERN, emissions into the atmosphere result from accelerator operation (e.g. ventilation from tunnels, experimental activities) and industrial activities (e.g. workshops) carried out on the various sites, and life on sites (e.g. heating plant, transport, commuting). Atmospheric emissions are monitored to guarantee that CERN activities comply with the applicable regulations in force in the Host States.

Greenhouse gas emissions at CERN arise from the operation of the Laboratory’s research facilities. The majority of emissions come from CERN’s core experiments and more than 78% are fluorinated gases. With climate change a growing concern, the Organization is committed to reducing its direct greenhouse gas emissions

CERN has a formal objective to reduce its scope 1 emissions by 28% by the end of LHC Run 3 in 2025 (compared to a 2018 baseline). To achieve this objective, in addition to ongoing repairs, upgrades, gas recirculation systems, etc. CERN will install a new cooling system for the key detectors, which replaces fluorinated gases with CO₂, which has a significantly lower global warming impact than fluorinated gases.

For further details please see CERN’s environment reports.

CERN SCOPE 1 EMISSIONS FOR 2017-2022 BY CATEGORY. “Other” includes air conditioning, electrical insulation, emergency generators and the fuel consumption of the CERN vehicle fleet. The emissions were significantly lower for 2019 and 2020, due to the accelerator complex being in its second long shutdown (LS2).