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Paper: The carbon footprint of proposed Higgs factories (Patrick Janot and Alain Blondel, 2022)

LIP-ECO | 29 November, 2022

"Estimating the carbon footprint of proposed future colliders. When it comes to selecting the next accelerator emissions may be as important as cost. "

Energy became a hot topic at CERN. The current energy crisis already led to a 2022/2023 energy saving plan that affects the acceleration complex operation as well as street lightning and building heating. But the real issue is long term. Beyond the energy crisis there is the climate crisis and all the concerns with environment-friendly and sustainable research.

Director-General Fabiola Gianotti decided CERN should become a role model for an environmentally-aware scientific laboratory. As part of the strategy to improve sustainability, CERN has been actively working to reduce its electricity consumption, essentially by improving the efficiency of several kinds of facilities; environmental reports are being published since a few years, and they are growing ever more transparent, complete and strategic, with clear and ambitious goals being set.

In addition, Several environmental projects have been approved and are in the pipeline —  technological breakthroughs applicable also in other domains could help make the particle physics community become part of the solution. But of course this anything but certain. For the moment particle physics infrastructures are, like mostly everything else, part of the problem, and the game is to try to minimize the damage.

In particular, any future large accelerator would most likely consume as much energy as a medium-sized city — but the carbon footprints of the various designs could be vastly different. And to be able to provide realistic estimations on consumption, emissions and other impacts is  crucial.

In a recent paper, Janot and Blondel make the exercise of estimating and comparing the carbon footprint (energy consumption and carbon emissions per Higgs boson produced) for different proposed future colliders. Estimations depend on many factors and vary widely. But when it comes to selecting the next accelerator carbon emissions will be crucial. While the approach in this paper is a good first step towards estimating these emissions, it focus on accelerator operations. There is work to be done concerning each facility’s construction and decommissioning, and also greenhouse gases produced by detectors.

According to Nature, the authors explained their motivations were two-fold: on the one hand, fighting global warming very important to both of them personally. On the other hand, credible environmental benchmarking will be essential to get the support from governments and the public when choosing the world’s next collider.

Here you can find the paper:

And more information on sustainability and environment at CERN and particle physics:

Such matters are currently being discussed within several groups, and in particular within the EPPCN communications network involving CERN and all members states —  CERN is to become a role model for an environmentally-aware research, and the labs in the member states should follow the trend. As a starting point, we are not all at the same level. Steps and goals will have to be set according to where we stand. Discussion within the community will be required.

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