CERN boffins are confident that fusion, the holy grail of cheap, safe power will be economical and usable within thirty years. It's a finger in the air sort of estimate, based on projects from the Age of Scientific Optimism, such as the Los Alamos and Apollo moon landing projects.

The Soviets built the first experimental fusion reactor in the 1950s, and the technique remains the basis of current investment. The (Joint European Torus) JET reactor in Culham, Oxfordshire was completed 25 years ago, and work is underway on ITER in Cadarache, France, a €10bn facility, backed by six countries (including China) plus the EU. The Czech Republic has a smaller-scale reactor, called Compass. All use magnets to force a fusion of two hydrogen isotopes, deuterium and tritium, releasing enormous amounts of energy. Eventually, it's hoped, more than goes in. ITER is designed to produce 500MW for 300 to 500 seconds with an input of 50MW.

"We'll certainly have it in fifty years," ITER's Neil Calder told the Swiss Broadcasting Corporation last week. But not if Greenpeace has its way.

Yes, the fuel for fusion is abundant, and far more productive than fossil fuel - one litre of seawater can produce as much as 30 litres of petrol. It's much safer than nuclear fission. And it doesn't release CO2. So what's the problem?

"Governments should not waste our money on a dangerous toy," Jan Van de Putte of Greenpeace International said when ITER was announced in 2005. Van de Putte predicted it will never be efficient - so why bother?

Spokesperson Bridget Woodman said: "Nuclear fusion has all the problems of nuclear power, including producing nuclear waste and the risks of a nuclear accident."

(Which must break the record for the number of false and contradictory assertions you can cram into a 17-word sentence. But that's par for the course these days. When you hear a phrase like "sustainable energy" the opposite is usually intended - the speaker is referring to an energy source that won't sustain anything for very long or very reliably.)

Greenpeace began life as a citizens' group devoted to fighting pollution and the whaling industry, but it's now a powerful de-industrialisation lobby. Its hostility to progress snags it well over $200m income a year. If a scientific breakthrough promises a better of quality of life, then the organisation is probably against it.

Two of Greenpeace's co-founders, Patrick Moore and Paul Watson long since departed: Watson to run his own anti-whaling group and Moore criticising its anti-human, anti-development agenda. "By the mid-1980s, the environmental movement had abandoned science and logic in favor of emotion and sensationalism," Moore lamented.

Fusion seems to exemplify what Moore means: an anti-modernity superstition. Greenpeace doesn't understand what fusion is, but whatever it is it will be scary, it will be bad, and it must be stopped. ®