portrait,Fabiola Gianotti,CERN,Director-General
Dr. Fabiola Gianotti, CERN's Director-General (Image: CERN)

A message from the Director-General

CERN was established in 1954 as a focal point for fundamental physics research in Europe, providing facilities that are beyond the reach of individual countries and fostering cooperation between European states through science. Today, the Laboratory has grown to provide a unique set of research infrastructures serving a worldwide community of scientists and has become a model of global collaboration. CERN also aspires to be a model for a sustainable and environment-friendly research organisation and to ensure that some of its technologies can help society to protect the planet.

Over recent years, climate and environment awareness has grown considerably. While CERN has always taken its environmental stewardship seriously, today we are making extra efforts to ensure that we can deliver all our objectives with minimum environmental impact while making a maximum contribution to society. This applies both to potential future facilities and to existing ones.

In 2020, the European particle physics community published an update of the European Strategy for Particle Physics and recommended that CERN carry out a feasibility study for a Future Circular Collider (FCC). It also recommended that “A detailed plan for the minimisation of environmental impact and for the saving and re-use of energy should be part of the approval process for any major project”. In other words, sustainability will be built into any future project at CERN.

For that reason, the FCC feasibility study team is looking closely at the environmental feasibility of the FCC, examining aspects ranging from the preservation of biodiversity to the use of excavated materials, developing more energy-efficient technologies and deploying renewable energy solutions. We will keep you fully informed of developments in this area in future reports.

Today, climate change and protecting the environment are among the greatest challenges that humanity faces. It is incumbent on all of us to play our part in mitigating the impact of human activity on it. Business as usual is not an option, and we at CERN are actively investigating how we can continue to advance the frontiers of human knowledge while minimising the environmental footprint of our facilities and being a positive contributor of solutions.

Fabiola Gianotti, Director-General

Benoit Delille, Head of the Occupational Health, Safety and Environmental Protection unit (Image: CERN)

A message from the Head of the Occupational Health and Safety and Environmental Protection unit

CERN’s third Environment Report covers the years 2021 and 2022, a period that was marked by the continuing COVID-19 pandemic and the emergence of war in Europe following Russia’s invasion of Ukraine. Both have had an impact on the data you will find in this report. Like most of the world, COVID-19 has changed the way in which CERN operates. Although the Laboratory has come back to life with people physically returning to the workplace, many now take advantage of the new possibility to telework part time and the amount of travel has significantly decreased. The result of this is clearly visible in our commuting and travel statistics and the accompanying environmental data. The Russian invasion contributed to volatility in the energy markets. Consequently, CERN has implemented additional energy-saving measures as a mark of social responsibility.

For a large part of this reporting period, CERN’s accelerator complex was undergoing a long shutdown for maintenance and upgrades. CERN’s environmental footprint during a long shutdown is markedly different to what it is in a period of accelerator operation. Our energy and water consumption are lower, for example, but our waste treatment rate is higher as we replace worn out and obsolete equipment.

Despite the challenging backdrop of the continuing pandemic, the shutdown objectives were all accomplished, and the accelerators progressively came back to life in 2021-2022, culminating in the successful restart of CERN’s flagship project, the Large Hadron Collider (LHC), in July 2022. The work carried out during the shutdown was designed to improve the performance of the accelerators and detectors and to improve their environmental credentials. The accelerator complex is now more efficient, delivering more data per unit of energy consumed. The experiments invested much effort in repairing leaks in their gas systems and worked towards replacing the current gases with more environmentally friendly ones.

This report also covers the new CERN Innovation Programme on Environmental Applications (CIPEA), which was launched in March 2022 and is funding its first eight projects. We include, for the first time, data on the scope 3 greenhouse gas emissions arising from procurement. Over the years since we embarked on our first environment report, we have learned a great deal about our footprint, implemented mechanisms to better understand and control it and increased our efforts to identify and develop technologies stemming from our core research that have the potential to benefit the environment. Although there is still some way to go, we have made considerable progress, which I encourage you to explore in this report.

Benoît Delille, Head of the Occupational Health and Safety and Environmental Protection unit

In brief

This reporting period saw the completion of the second long shutdown and the restart of the accelerator complex (Run 3) with a view to reaching the new collision energy of 13.6 TeV at the Large Hadron Collider (LHC). In some domains environmental indicators may be very different during shutdown years compared to operation years, so they are shown for both years to highlight this, where relevant. 2022 indicators are prominently shown for those domains where priority objectives have been defined, namely Energy, Emissions and Water and Effluents.


1215 GWh

The Laboratory is committed to limiting rises in electricity consumption to 5% up to the end of Run 3 compared to the 2018 baseline year, which corresponds to a maximum target of 1314 GWh, while delivering significantly increased performance of its facilities. It is also committed to increasing energy reuse.

In 2021 and 2022, CERN consumed 991 GWh and 1215 GWh of electricity respectively. In addition, the Organization consumed 67 GWh (240 TJ) and 51 GWh (184 TJ) of energy generated from fossil fuels in the two years respectively.


184 173 tCO2

CERN’s objective is to reduce direct emissions by 28% by the end of Run 3 compared to the 2018 baseline year, which corresponds to a maximum target of 138 300 tCO2e

The scope 1 emissions in 2021 and 2022 were 123 174 and 184 173 tonnes of CO2 equivalent (tCO2e) respectively. 

The total amount of scope 2 greenhouse gas emissions due to CERN's electricity consumption was 56 382 and 63 161 tCO2e in 2021 and 2022 respectively. 

Total scope 3 emissions arising from business travel, personnel commuting, catering, waste treatment and water purification amounted to 7813 and 8956 tCO2e in 2021 and 2022 respectively.

Scope 3 emissions arising from procurement, which are reported for the first time, amounted to 98 030 tCO2 and 104 974 tCO2 in 2021 and 2022 respectively. 


3234 ML

The Laboratory is committed to keeping the increase in its water consumption below 5% up to the end of Run 3 compared to the 2018 baseline year, which corresponds to a maximum target of 3651 ML, despite a growing demand for water cooling at the upgraded facilities.

In 2021 and 2022, CERN used 2661 and 3234 megalitres of water respectively. 


< 0.01 mSv

The European annual dose limit for public exposure to artificial sources is 1 mSv. CERN is committed to keeping its contribution to no more than 0.3 mSv per year.

The actual dose received by any member of the public living near the Laboratory was less than 0.01 mSv in the reporting period, which is more than 100 times lower than the average annual dose received from medical exposure per person in Switzerland.


69% recycled

CERN’s aim has been to increase its recycling rate for non-hazardous waste. The recycling rate rose from 56% in 2018 to 69% in 2022. 

In 2021 and 2022 respectively, CERN disposed of 5111 tonnes and 8812 tonnes of non-hazardous waste, and of 1544 tonnes and 1295 tonnes of hazardous waste, including 307 and 519 tonnes of radioactive waste. 


45 dBA at night

CERN is committed to restricting noise at its site perimeters to 70 dBA during the day and 60 dBA at night.  

Over this reporting period, CERN implemented measures to improve its noise management, including the installation of an online real-time monitoring system at Point 2 of the LHC and Point 4 of the SPS. Average noise levels measured on the boundaries of CERN’s sites are typically around 50 dBA during the day and 45 dBA at night.


18 species of orchids

Inventories of flora and fauna were conducted in 2022. A further two species of orchid were identified, bringing the total on the CERN sites to 18, as well as 62 species of Lepidoptera and 32 species of Orthoptera.


8 environmental projects

In 2022, CERN launched the Innovation Programme on Environmental Applications (CIPEA), which spans four focus areas where CERN’s know-how can be of use, namely renewable and low-carbon energy; clean transportation and future mobility; climate change and pollution control; and sustainability and green science.

Eight projects were selected for implementation with the financial support of external partners or the CERN Knowledge Transfer fund. 

Full report & Glossary

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All CERN's environment reports are available in PDF