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."
They already share ownership through American entertainment and broadcasting magnate John Malone's companies. Liberty Global was already the biggest shareholder in Formula E when Liberty Media bought F1 in 2017.
"The step for Formula One to go electric will be a big and difficult one," Rosberg said. "If that ever happens."
It might become inevitable, with a fast-warming planet to be protected, and sports conscious of its role. The Intergovernmental Panel on Climate Change issued a gloomy report last week which said the difference between life and death for multitudes of people around the world could be whether world leaders find a way to reduce future warming caused by humans by less than a single degree Fahrenheit.
"It's a real problem out there in the world and we need to do what we can as fast as possible to help all together," Rosberg said.
"If the whole world is selling and driving electric cars," he added, "it doesn't make sense for Formula One to be combustion engines, so that moment will come. The advantage is that Formula One and Formula E have the same owner."
Although the cars are quieter compared to the ear-splitting, fuel-guzzling engines in F1, the new Gen 2 models which run faster and longer have been introduced.
Nissan and BMW will be debuting on the grid when the fifth Formula E championship begins in Saudi Arabia in December. There has also been a high-profile signing for the series: Former F1 driver Felipe Massa racing for Venturi, the Monaco-based team co-owned by actor Leonardo Di Caprio.
Stoffel Vandoorne announced on Monday that he is also making the switch from F1, joining the Mercedes-linked HWA Racelab Formula E team after leaving McLaren at the end of this season.
Rosberg is already looking forward to the following season when Mercedes-Benz and Porsche appear on the grid.
"That will be a spectacle everyone will want to watch," Rosberg said. "They need to showcase their electric technology in Formula E. None of them can afford to lose."