Professor Giles Harrison, of the University of Reading, is working on the research and said it is "intended to bring blue-sky thinking to cloud and rain".

He said: "Our project is about changing the balance of charges on the tiniest cloud droplets, a neglected aspect of clouds which could revolutionise our ability to manipulate rainfall in areas that need it most."

Even if this uses a "neglected" aspect of clouds, I also wonder about balance in the water cycle.