Nuclear Fusion

Q: What world-changing idea, small or big, would you like to see implemented by humanity?

A: This is easy. I would like to see the development of fusion power to give an unlimited supply of clean energy, and a switch to electric cars. Nuclear fusion would become a practical power source and would provide us with an inexhaustible supply of energy, without pollution or global warming.

— Stephen Hawking (Brief Answers to the Big Questions)