Nasa estimates that if a 35% increase in heat transfer could be achieved from its magma chamber, Yellowstone would no longer pose a threat. The only question is how?

One possibility is to simply increase the amount of water in the supervolcano. But from a practical perspective, it would likely be impossible to convince politicians to sanction such an initiative.

“Building a big aqueduct uphill into a mountainous region would be both costly and difficult, and people don’t want their water spent that way,” Wilcox says. “People are desperate for water all over the world and so a major infrastructure project, where the only way the water is used is to cool down a supervolcano, would be very controversial.”