Environmental sustainability in basic research: a perspective from HECAP+

For decades, the most ambitious questions in physics have been answered by building machines of staggering scale. These are not the microscopes of a biology lab or the telescopes of an astronomy department, but vast underground tunnels and massive detectors designed to smash particles together or listen for the faint whispers of the cosmos. Scientists in fields like high-energy physics, cosmology, and nuclear physics use these tools to understand the fundamental laws of the universe. The work requires immense amounts of electricity to power the machines, vast computing power to sort through the resulting data, and frequent travel for researchers to meet and share their findings. For a long time, the focus was almost entirely on the science itself, with the environmental cost of running these operations treated as a background detail, much like the electricity bill for a home.

However, the climate crisis has forced a reckoning. The scientific community that studies the origins of the universe is now turning its gaze inward to examine its own footprint. A new perspective from the HECAP+ community—a group encompassing high-energy physics, cosmology, astroparticle physics, and nuclear physics—offers a clear-eyed assessment of how their work impacts the planet. The authors, a coalition of researchers and experts, argue that the tools and practices of basic research are contributing significantly to global greenhouse gas emissions. They do not suggest stopping the science; instead, they propose a fundamental shift in how this science is planned, funded, and conducted. The goal is to align the pursuit of knowledge with the urgent need to protect the climate, ensuring that the quest to understand the universe does not come at the expense of the planet that hosts it.

The document begins by establishing the scale of the problem. It compares the emissions generated by a single researcher in these fields to the average person on Earth. The data reveals a stark disparity: a researcher at a major facility like CERN, the European Organization for Nuclear Research, generates roughly fifteen tons of carbon dioxide equivalent per year just from their work. This is more than double the global average per person. When the researchers break down where this pollution comes from, they find it is not just the giant particle accelerators. A significant portion comes from the computers needed to analyze the data, the energy used to heat and cool the laboratories, the food served at conferences, and the travel required to keep the international collaborations running. The paper emphasizes that these are choices, not inevitable consequences of doing science. The way a detector is designed, the software used to process data, and the type of food served at a meeting all have measurable environmental costs.

One of the most surprising findings concerns the computers. As experiments generate more data, the demand for computing power grows exponentially. The paper notes that for some researchers, the electricity used by their computers accounts for the vast majority of their work-related emissions. This is not just about turning off lights; it is about the efficiency of the code itself. The authors point out that writing software that is more efficient can drastically reduce the energy needed to run simulations. They also highlight the hardware, noting that the manufacturing of computer chips and servers creates a large portion of their lifetime emissions. The document suggests that keeping equipment in use for longer and repairing it rather than replacing it is a powerful way to cut down on this impact.

Energy consumption is another major pillar of the discussion. The paper details how facilities are exploring ways to power their operations with renewable energy. It highlights a project in the Middle East where a particle accelerator is powered almost entirely by solar energy, proving that even large-scale scientific instruments can run on clean power. The authors also discuss the potential of using waste heat from data centers to warm nearby buildings, turning a byproduct of computing into a useful resource. However, they are careful to note that simply switching to green energy is not a magic bullet. The transition requires careful planning to ensure that the energy is available when needed and that the infrastructure to support it does not create new environmental problems.

Travel presents a complex challenge for a community that relies on international collaboration. The paper acknowledges that while video calls are a good alternative, they cannot replace all face-to-face meetings, especially for building trust and mentoring early-career scientists. Instead of banning travel, the authors recommend a more thoughtful approach. They suggest prioritizing train travel over short-haul flights, which are particularly carbon-intensive, and organizing conferences in ways that minimize the need for long-distance travel. They also point out that reducing travel can actually make science more inclusive, allowing researchers from regions with fewer resources to participate more fully without the burden of expensive and time-consuming trips.

Food is another area where small changes can have a large impact. The document points out that the food served at conferences and in laboratory cafeterias contributes significantly to emissions, particularly when it includes meat and dairy products. The authors provide examples of conferences that have successfully switched to plant-based catering, showing that it is possible to feed large groups of people without relying on high-emission foods. They argue that making plant-based options the default, rather than the exception, is a simple step that institutions can take immediately. This shift also addresses issues of equity, as plant-based diets are often more accessible to people with different cultural or religious dietary needs.

The paper also tackles the issue of waste, particularly the electronic waste generated by outdated equipment. It calls for a culture of "reduce, reuse, repair, and recycle" within the research community. The authors describe how some institutions are finding new uses for old materials, such as repurposing heavy concrete blocks from decommissioned experiments to build new structures. They urge funding agencies and institutions to require that new projects include a full assessment of their environmental impact from the very beginning, including how the equipment will be disposed of at the end of its life. This "life-cycle" thinking ensures that the environmental cost is considered at every stage, from the mining of raw materials to the final disposal of the machine.

Ultimately, the document is a call to action for the entire scientific community. It argues that scientists have a unique responsibility to lead by example. Because their work is often funded by the public and supported by governments, they must demonstrate that their research is sustainable. The authors propose a series of concrete steps for individuals, research groups, and institutions. These range from simple personal choices, like turning off equipment when not in use, to major policy changes, such as requiring environmental impact statements for all new projects. They emphasize that these changes are not about limiting scientific progress but about ensuring that science can continue in a world that is safe and habitable.

The paper concludes with a message of hope and urgency. It acknowledges that the path forward is difficult and that there are no easy solutions. However, it also highlights that the scientific community has a long history of solving complex problems and working together across borders. By applying that same creativity and collaboration to the challenge of sustainability, the authors believe that the field can transform itself. They see this not as a burden, but as an opportunity to make science more efficient, more inclusive, and more aligned with the values of the society it serves. The document serves as a blueprint for a future where the pursuit of knowledge and the protection of the planet are not competing goals, but mutually reinforcing efforts.