The world has been trying to master this limitless clean energy source since the 1930s. We’re now closer than ever

Saint-Paul-lez-Durance, France — From a small hill in the southern French region of Provence, you can see two suns. One has been blazing for four-and-a-half billion years and is setting. The other is being built by thousands of human minds and hands, and is — far more slowly — rising. The last of the real sun’s evening rays cast a magical glow over the other — an enormous construction site that could solve the biggest existential crisis in human history.

It is here, in the tiny commune of Saint-Paul-lez-Durance, that 35 countries have come together to try and master nuclear fusion, a process that occurs naturally in the sun — and all stars — but is painfully difficult to replicate on Earth.

Fusion promises a virtually limitless form of energy that, unlike fossil fuels, emits zero greenhouse gases and, unlike the nuclear fission power used today, produces no long-life radioactive waste.

Mastering it could literally save humanity from climate change, a crisis of our own making.

If it is mastered, fusion energy will undoubtedly power much of the world. Just 1 gram of fuel as input can create the equivalent of eight tons of oil in fusion power. That’s an astonishing yield of 8 million to 1.

Atomic experts rarely like to estimate when fusion energy may be widely available, often joking that, no matter when you ask, it’s always 30 years away.

But for the first time in history, that may actually be true.

In February, scientists in the English village of Culham, near Oxford, announced a major breakthrough: they generated and sustained a record 59 megajoules of fusion energy for five seconds in a giant donut-shaped machine called a tokamak.

It was only enough to power one house for a day, and more energy went into the process it than came out of it. Yet it was a truly historic moment. It proved that nuclear fusion was indeed possible to sustain on Earth.

This was excellent news for the project in France, the International Thermonuclear Experimental Reactor, better known as ITER. Its main objective is to prove fusion can be utilized commercially. If it can, the world will have no use for fossil fuels like coal, oil and gas, the main drivers of the human-made climate crisis.

There has been a huge sense of momentum at ITER since the success in the UK, but the people working on the project are also undergoing a major change. Their director general, Bernard Bigot (pronounced bi-GOH in French), died from illness on May 14 after leading ITER for seven years.

Before his death, Bigot shared his infectious optimism for fusion energy from his sunny office, which overlooked the shell of ITER’s own tokamak, a sci-fi like structure still under construction.

“Energy is life,” Bigot said. “Biologically, socially, economically.”

When the Earth was populated by less than a billion people, there were enough renewable sources to meet demand, Bigot said.

“Not anymore. Not since the Industrial Revolution and the following population explosion. So we embraced fossil fuels and did a lot of harm to our environment. And here we are now, 8 billion strong and in the middle of a drastic climate crisis,” he said.

“There is no alternative but to wean ourselves off our current…