We, CERN TH department, recognise the environmental impact resulting from the extensive professional travel, particularly by air, customary in our scientific community. We subscribe to the urgent need to reduce our greenhouse gas (GHG) emissions rapidly in accordance with the goals of the Paris climate agreement and of the CERN environment reports. At the same time, we value international exchange as a pillar of scientific progress and strive to provide excellent research conditions for international researchers at CERN and beyond, in particular promoting young scientists. This document provides some guidelines on achieving these goals, consciously balancing scientific value and environmental cost.

We consider hybrid and online talks best practice, and will continue to offer this format for seminars and conferences organised by CERN TH. We also recognise the value of in-person interaction for scientific exchange and collaboration. Which format is best suited for the scientific goals of a given event needs to be evaluated on a case by case basis, taking also into account that online events offer broader access to the worldwide scientific community. We will improve the technology support for online events to facilitate interaction and collaboration.

We critically consider the scientific value of each business trip and replace it by a virtual meeting when adequate. We maximise the scientific value of an in-person trip, considering for example a longer stay or a combination of several trips. We explicitly encourage our visitors to do the same.

When travel is necessary, we recognise that the GHG emissions of air travel are many times higher than travel by train for trips within Europe. We strongly encourage the use of trains whenever possible and regularly evaluate our internal regulations to empower climate conscious choices. When air travel is necessary, we encourage the use of a GHG emission calculator to compare the environmental cost of different flight options.

We plan to systematically quantify and monitor the GHG emissions related to the operations of CERN TH, evaluating and improving our measures for GHG reduction.

For more information see the admin e-guide sections on duty travel and organizing conferences