Climate, Science, and the FCC: Think Clearly, Choose Wisely, Act Swiftly

In the summer of 2026, a wave of heat swept across France, turning forests into tinderboxes and forcing families to flee their homes. The air grew thick and unbreathable, a stark reminder that the climate crisis is no longer a distant warning but a present emergency. In the face of such disasters, a difficult question arises for the scientific community: should they scale back their most ambitious projects to save energy, or does the pursuit of knowledge remain essential to solving the very problems we face? This dilemma centers on a proposed machine called the Future Circular Collider, a massive underground ring designed to smash particles together at energies far higher than anything currently possible. Its purpose is to answer some of the universe's deepest mysteries, such as what dark matter is made of and why the universe is filled with matter rather than antimatter. However, critics argue that building such a machine would consume too much electricity and generate too much carbon pollution to be justified in a world fighting for its survival. They suggest that cancelling the project would be a powerful moral statement, freeing up billions of dollars and tons of emissions to be used elsewhere.

Two physicists, Patrick Janot and Christophe Grojean, set out to examine these accusations not with emotion, but with a careful accounting of facts. They treat the debate as a balance sheet, weighing the environmental cost of the machine against the scientific knowledge it would produce and the potential benefits of delaying or cancelling it. Their analysis begins by looking at the carbon footprint of the collider. While the machine would indeed emit roughly one to two million tonnes of carbon dioxide equivalent over its lifetime, the authors place this number in a global context. They point out that the entire world emits nearly 58 billion tonnes of carbon dioxide every year, with electricity generation alone responsible for more than a quarter of that total. When the collider's emissions are divided by the eight billion people on Earth, the impact amounts to just a few grams per person per year. The authors argue that while every reduction in pollution matters, cancelling the collider would avoid only a tiny fraction of global emissions. In contrast, transforming how the world generates electricity—by replacing coal and gas with low-carbon sources like wind, solar, and nuclear power—could prevent hundreds of thousands of times more pollution. They conclude that focusing on the collider as a primary target for climate action is a mistake of scale; it treats a small symbol as if it were the main cause of the problem.

The essay also tackles the claim that the collider is an energy "monster" that would require the output of two massive nuclear reactors. The authors clarify that the machine's actual power needs are far lower than this image suggests. Depending on how it is operated, the collider would consume about 1.3 terawatt-hours of electricity a year. This is a significant amount, but it is comparable to the energy used by a single large data center or the current operations of the Large Hadron Collider. Furthermore, the authors explain that the machine does not need to run constantly. It could be designed to operate flexibly, drawing power when renewable energy from the sun and wind is abundant and scaling back when the grid is under strain. This flexibility could reduce its reliance on nuclear power to a tiny fraction of the output of the two reactors mentioned by critics. The authors also explore a new possibility: the use of natural hydrogen found underground. While still uncertain, this resource could one day provide a way to store energy for days when renewable sources are scarce, potentially allowing the collider to run without any nuclear power at all.

Beyond the numbers, the authors address the argument that the project should be postponed until better, cleaner technology arrives. They warn that time is not a neutral resource in science. Postponing the project for decades would mean losing the momentum of a global scientific community, dispersing teams of experts, and losing the skills of a generation of young researchers. The knowledge gained from the collider is not just about finding new particles; it is about the process of discovery itself. The authors argue that artificial intelligence, while powerful, cannot replace the need for new experiments. AI can analyze existing data, but it cannot create the new events that only a higher-energy machine can produce. If the collider finds nothing new, that silence is still a valuable answer, telling scientists that the laws of nature are different than they imagined and guiding them toward new paths. If it does find something, it could unlock technologies that benefit society in ways we cannot yet predict, just as previous particle physics research led to breakthroughs in medical imaging and cancer treatment.

The essay also confronts the emotional charge of the debate, specifically the claim that the collider's emissions would cause five hundred premature deaths. The authors explain that this figure comes from a statistical rule that spreads the risk of climate change across the entire population. It does not mean that the machine will directly kill five hundred people, nor does it account for the lives that the knowledge gained from the machine might save. They argue that using such a number to condemn a project is misleading because it ignores the full picture. A hospital or a university also has a carbon footprint, but we do not cancel them because of it; we weigh their benefits against their costs. The authors insist that the same logic must apply to the collider. We must look at the whole balance sheet: the emissions it produces, the knowledge it generates, the technologies it inspires, and the international cooperation it fosters.

Ultimately, the authors conclude that the climate emergency does not call for a society defined by renunciation and shrinking horizons. It calls for a transformation in how we produce energy and how we solve problems. They argue that cancelling the collider would not solve the climate crisis; it would only remove one small piece of the puzzle while leaving the larger, more difficult challenges of decarbonizing the global economy untouched. The path forward, they suggest, is to build the future we want by transforming our systems, not by sacrificing our capacity to understand the world. The collider should be built, but it must be built with a commitment to efficiency, flexibility, and the development of new low-carbon technologies. The authors believe that a society that gives up on discovery condemns itself to mere endurance, while a society that faces the facts and chooses the right levers can build a future that is both sustainable and full of wonder. The responsibility, they write, remains entirely our own.