London — Scientists at a lab in the United Kingdom have made a major breakthrough in creating electricity through nuclear fusion. The development has put them on course, they say, to tapping an unlimited source of clean power — with no greenhouse gas emissions  — in a matter of decades.

Nuclear fusion is the opposite of nuclear fission, the technology used today in nuclear power plants around the world. Fission breaks particles apart to create energy. Fusion forces particles together, and can be done, the scientists say, much more safely, with much less radioactive material and much lower risk of accidents.

The scientists haven’t yet managed to conduct fusion in a way that produces enough electricity to be the clean power supply they believe it eventually can be, but they say it would be unfair to humanity and the planet not to keep pushing for it.

“Fusion has such a high potential to solve, or to contribute to solving, the energy issue… in a compatible way with keeping our planet healthy,” Dr. Ambrogio Fasoli, physics professor and chair of the international research consortium that made the breakthrough, told CBS News. “It would be totally immoral in the history of mankind not to try and exploit it.”

What was the breakthrough?

The breakthrough by Fasoli’s team at the U.K.-based JET laboratory saw them create a miniature star and, using magnetic fields, they managed to hold it together for a record-setting five seconds. The star only produced enough electricity to boil about 60 teapots full of water, and it required more power to create than it emitted.

But Fasoli said those 60 teapots of energy were remarkable, because the experiment validated design choices that have been made for a much larger reactor, currently being constructed in France, called ITER.

ITER is a multi-decade international project run by 35 countries, including the United States, China, Russia, and European Union nations. When finished, scientists believe it will provide a blueprint for the sustainable, global commercialization of fusion power.

“A planetary challenge has to be attacked with a planetary approach,” Fasoli said. “This scientific, fantastic achievement underlies the fact that, even when you have political difficulties, science and, in a sense, technology, has no barriers. We all work together. We find ways to collaborate regardless of the political setup… Ultimately, the goal is really a goal for the good of all mankind.”

Fasoli said he expected the ITER project to be completed by around 2050, and that it would bring scientists to the point of being able to design, in collaboration with private industry, a demo commercial fusion reactor.

It may seem a long way off, but harnessing the power of stars on Earth was never likely to be easy.