Highlighting fresh concerns about global warming, Nico Rosberg foresees an eventual merger between the Formula One championship and the Formula E electric motorsport series.
The German driver retired from F1 after winning his only title in 2016, and he has since invested in the four-year-old Formula E championship, which he said is now worth 750 million euros (R12.3bn).
While F1 remains more attractive to sponsors and fans, the upstart series is showing increasing commercial appeal. Heineken, which already sponsors F1, was announced on Monday as the official beer and cider backer of the electric street racing championship under a five-year deal.
That unified approach to marketing across both series points to a future where they join forces.
"Maybe we will never even get to that point (where Formula E is bigger than F1) and we will just see a merger between Formula One and Formula E before that," Rosberg said in a telephone interview with The Associated Press on Monday. "When the moment comes that Formula One needs to go electric, which will happen, maybe you will just see a merger then."