Can CERN’s $19bn effort to rewrite physics survive a fracturing world?

Why does matter dominate over antimatter in the universe? CERN is trying to find out. Fabrice Coffrini / AFP

The science behind CERN’s proposed Future Circular Collider is settled. The funding is not. In a fracturing world, the lab faces the biggest challenge in its 70-year history.

The CERN particle physics research laboratory outside Geneva is pursuing its next chapter. The lab’s next-generation particle collider, the Future Circular Collider (FCC), has the backing of the scientific community and has passed a feasibility study conducted by 1,500 experts. The European physics community has officially recommended it as the next flagship collider. When the CERN Council meets for a special session in Budapest in May, director-general Mark Thomson is confident they will greenlight the project.

“There is an absolute, clear consensus within the particle physics community that FCC is the right way to go,” he says.

What is rather less settled is how to pay for it.

The FCC’s first phase carries a price tag of CHF15 billion – around $19 billion. Half is expected to come from member state contributions. Thomson hopes that the EU will pledge €3 billion (CHF2.7 billion) in 2027. Private donors committed €860 million last December, but that still leaves CERN roughly CHF4 billion short. The organisation is looking to close the gap through further private donations and contributions from non-member states.

If CERN can secure funding and start the project, it will lay the groundwork for making new breakthroughs and attracting new generations of particle physicists to Geneva. Yet, the budget plan being drawn up is an optimistic one in a challenging moment for international relations.

The future of CERN: a series

The stories in this series look at where the world’s largest particle physics laboratory stands in its scientific ambitions and its efforts to remain an international crossroads for understanding our universe. 

Geopolitical fault lines 

The international scientific cooperation that built the Large Hadron Collidor (LHC) was forged in the 1990s, a different era. Germany, the lab’s largest annual contributor, supports the FCC in principle but has pushed back on the proposed funding mechanism, objecting to the use of the EU’s multi-annual budget.

The UK, another longtime CERN member and Thomson’s home country, wants to cut funding to particle physics programmes by 30%. The cuts threaten existing CERN collaborations, including a planned experiment on the upgraded LHC.

In the US, President Donald Trump’s administration has repeatedly cut scientific programs, and particle physics doesn’t seem to have the same priority to the White House as AI or quantum technologyExternal link. Despite the US not being a CERN member state, they have created a strong partnership with the lab over the years. US researchers make up the biggest community at CERN, with 2,000 collaborators. The US has also contributed financially to various experiments, such as granting about CHF80 million for the development of the new magnets of the upgraded LHC. “I am confident that the relationship between CERN and the US will continue,” Thomson says.

Russia, a partner even during the Cold War, was ousted from CERN following the invasion of Ukraine. Thomson says Moscow’s scientific, financial and engineering contributions “have been significant” but doesn’t know if or when it might be reintegrated.

Amid these hurdles, there is one piece of good news for the lab. China has quietly shelved plans for its own competing 100 km supercollider, deferring a decision until 2030.

“It’s an opportunity for us,” says Fabiola Gianotti, who led CERN as director-general for ten years until January. “If approved now, that project would have had a good chance of starting earlier than the FCC.” China has since declared an interest in collaborating with CERN on the FCC instead.

>>“The most extraordinary instrument ever built”? Watch our video about the FCC:

Opposition closer to home 

Beyond European capitals and Washington, CERN faces a different kind of challenge: the people who would live above the new machine. A network of Swiss and French associations, led by the group Noé21, has mounted a sustained campaign. They object to the project’s significant electricity consumption, the expected 8 million cubic metres of excavation material, and what they call an inadequately quantified carbon footprint.

“I understand [CERN’s] needs, but it doesn’t mean we must accept something that will cost tens of billions – no one knows how much it will cost – and poison the region for years to come,” says Jean-Bernard Billeter, board member of Noé21.

In February, around 100 residents gathered in Presinge, a municipality east of Geneva that would host one of the FCC’s surface sites. Claude Schaeppi Borgeaud, a local artist, has not ruled out taking the case to the European Court of Human Rights. Christina Meissner, a member of the Geneva cantonal parliament, said at the February event: “We are promised consultation. I haven’t seen any of that yet.” 

Four months of public debates and consultation on the FCC between CERN and members of the public are set to begin in May. Noé21 criticised in a press release that “the first events announced appear to be one-way information sessions rather than a debate”.

CERN’s feasibility study proposes to reuse excavation debris in agriculture and civil construction, and projects that technological advances will keep electricity consumption in line with the current LHC. The lab argues the construction would generate roughly one-third of the carbon emissions of the 2024 Paris Olympics. For Billeter, these remain projections. He points to the US Superconducting Super Collider – an 87 km accelerator abandoned mid-construction in Texas – as a cautionary precedent.

Thomson acknowledges the gap. “We have to demonstrate that we can build this machine in an environmentally responsible way, taking into account the concerns of the population,” he says.

>>More on what the next-generation particle collider will be able to do in the article below:

Plan B – and the cost of compromise 

If the full CHF15 billion cannot be assembled, CERN has a fallback. A scaled-down FCC would operate at lower maximum energies and include two detectors rather than four, reducing costs by around 15% – more than CHF2 billion.

“These are not small reductions, but even the de-scoped FCC is still scientifically superior to the other options,” says Thomson.

Maria Spiropulu, a CERN collaborator who works at the California Institute of Technology, sees the Plan B framing as tactically shrewd. “It’s super smart, as it shows that we are going for it; if you propose another option just to save money, you risk shrinking the field.”

The case for going ahead 

The CERN Council will begin its formal evaluation this spring and aims to reach a final decision by 2028. If approved, excavation could begin around 2033, with the collider operational by 2046.

What is at stake, says Costas Fountas, the President of the CERN Council, goes beyond any single experiment. He says it’s about “The leadership in higher energy physics, and the top 5% of people who will go anywhere to do the science they want.” 

Scientists also highlight the social and economic benefits that the FCC could create, beyond building a new understanding of the origins of the universe. CERN was where the World Wide Web was invented, after all.  

“If FCC happens, we’re on a path to secure the future of this lab for 100 years,” says Maurizio Pierini, a particle physicist at CERN. The question now is whether political will can match scientific ambition.

Rebuilding the LHC – and what’s already at risk 

While the FCC’s fate is debated, CERN’s existing machine is already heading into surgery. On June, the Large Hadron Collider shuts down for a four-year upgrade – the High Luminosity LHC – designed to produce around ten times more collisions than the original machine. 

The upgrade is already attracting geopolitical friction. The UK’s proposed 30% cut to particle physics funding threatens an experiment planned on the upgraded machine – a sign that the political pressures facing the FCC are not a future problem but a present one. 

The HiLumi was always conceived as a bridge: keeping CERN at the frontier of scientific discovery while the case for the FCC was made. Whether it becomes a bridge to the future, or a last hurrah for the current era of European particle physics, may depend on decisions made in the next two years. 

Edited by Gabe Bullard and Veronica De Vore/dos