CERN retention basin
An example of CERN’s water management strategy is the construction in 2020 of a retention basin near the Prévessin site. The basin will retain and, under certain conditions, regulate water from rainfall flowing off the Prévessin site into the Lion in order to retain incidental pollutants. (Image: CERN)


"I believe CERN should become a role model for an environmentally aware scientific laboratory."
  – Fabiola Gianotti, Director-General of CERN


Diagram of the 11 environmental domains at CERN
CERN follows up on 11 environmental domains to mitigate and limit the impact of our activities on the environment.

Over the decades, CERN has become a byword for excellence in research, establishing itself as a model for scientific collaboration across borders, technological innovation, training and education.

Today, environmental responsibility joins this list. Good environmental stewardship stands prominently among the Management’s objectives and is embedded in every corner of the Organization, with a strategic, proactive approach across the Laboratory and among CERN’s worldwide scientific community.

Contributing to the achievement of several of the environment-related UN Sustainable Development Goals (SDGs) is a natural continuum in this context, for example by improving our performance and forging partnerships with others.

Driven by this commitment to environmentally responsible research, CERN has implemented many initiatives over the years that have helped to reduce the impact of its activities on the environment. This page provides more information on these activities across different thematic areas.

CERN is fully committed to environmental protection and transparent reporting. CERN's public environment reports set out reporting frameworks, setting and monitoring concrete goals for constant improvement.

Biennial reports


During the period covered by the latest environment report, 2019-2020, CERN’s accelerator complex was in its second long shutdown. Due to this shutdown, several environmental indicators show a different pattern from the previous reporting time frame of 2017-2018. These highlights only include 2019 indicators, given that 2020, with the COVID-19 pandemic, was not representative of a normal year.


428 GWh

In 2019, CERN consumed 428 GWh of electricity and 68 GWh of fossil fuel. CERN’s electricity consumption during this period was about 64% lower than when the accelerator complex is running.

The Laboratory is committed to limiting rises in electricity consumption to 5% up to the end of 2024 (baseline year: 2018), while delivering significantly increased performance of its facilities. CERN is also committed to increase energy re-use.



78 169 tCO2e

In 2019, CERN’s direct greenhouse gas emissions (scope 1) were 78 169 tonnes of CO2 equivalent (tCO2e) which is less than half of the amount emitted annually over the period 2017-2018 when the accelerators were running.

Indirect emissions arising from electricity consumption (scope 2) were 10 672 tCO2e. In addition, indirect emissions from water purification, waste treatment, business travel, personnel commutes and catering (scope 3) were 12 098 tCO2e.

CERN’s immediate target is to reduce direct emissions by 28% by the end of 2024 (baseline year: 2018).



57% recycled

In 2019, CERN eliminated 5589 tonnes of non-hazardous waste, of which 57% was recycled.
The Laboratory also eliminated 1868 tonnes of hazardous waste.

CERN’s objective is to increase the current recycling rate.



2006 ML

In 2019, CERN drew 2006 megalitres (ML) of water, mostly from Lake Geneva. This is about 47% less than in operational years.

The Laboratory is committed to keeping its increase in water consumption below 5% up to the end of 2024 (baseline year: 2018), despite a growing demand for water cooling of upgraded facilities.



16 species of orchids

In 2019, a new species of orchid was discovered on CERN’s sites, bringing the total to 16 species.

CERN land includes 258 hectares of cultivated fields and meadows, 136 hectares of forest and three wetlands.

Environmental domains at CERN

Conserving biodiversity
Minimising atmospheric emissions
Monitoring water releases
Limiting soil pollution
Reducing noise emissions
Improving energy efficiency
Managing waste centrally
Optimising risk management
Monitoring and minimising exposure
Managing and mitigating
Preventing incidents proactively