Carlos Ghosn, the fast-talking head of the Renault-Nissan alliance, is not keen to be drawn on targets for electric car sales. A 2011 prediction of 1.5m Renault-Nissan electric vehicles by 2016 turned out to be wildly optimistic. The group just passed the 250,000 mark.

Ghosn was not alone. President Barack Obama predicted 1m electric cars in the US by 2015: in January the total was 280,000.

Unlike Branson, Ghosn does not want to stick his neck out. But as head of the companies which sell more than half the electric cars in the world, what Ghosn thinks about how fast the market will grow matters.

Transport contributes 23% of global greenhouse gas emissions, so the fundamental driver will be the ambition of the world in tackling climate change, Ghosn told the Guardian in an interview. “When we know exactly where the EU, US, China will be heading in 2030, I can tell you exactly how much electric cars will be needed,” he says, referring to a crunch UN summit in Paris in November.

The reasons for people being relatively slow to buy electric cars are simple, Ghosn says: “If there is a price penalty, they just don’t buy. If there is range anxiety, they just don’t buy.”

He says Renault-Nissan are working on cutting the cost of the cars, which he says largely comes down to volume, with electric cars currently making up a tiny proportion of the 85m new cars sold globally each year.

“This is a scale problem,” Ghosn says. “The technology fundamentally has nothing expensive. If you come to the basic physics of an electric car, it is not supposed to be more expensive than a combustion engine.” Government subsidies for cars are also key, he says, as is the building of a network of charging points.

Ghosn is also president of ACEA, the European automobile manufacturers association, which has been criticised for lobbying to weaken EU fuel efficiency targets. It is a charge he robustly rejects: “If you are worried about the total CO2, there is an obvious solution. It is to stop the old cars. This would be radical, but politically extremely difficult.” But he says emissions limits will also be important in accelerating electric car sales.

“Ten years ago people thought that electric cars would never make it, they thought electric cars were like a golf cart, something slow, bulky, not very attractive,” he says. “Now they see the [Renault] Zoe, the [Nissan] Leaf, the Teslas etc and they think electric cars can be fun. They see Formula E and see the cars can be very powerful and go very fast. The idea that electric cars are normal cars, which is a big revolution from 10 years ago, has taken place.”

Ghosn raised the intriguing prospect of Renault, a major player in Formula One for many years, exiting the high-octane race series as it increases its involvement in the nascent Formula E series.

“The only thing that is certain today is that we are going to be bigger in Formula E,” he says. “We could be big in Formula E and absent in Formula One. Everything is open.”

Ghosn also delivered a barely-disguised barb at the F1 Red Bull team boss, Christian Horner, who has criticised the Renault engines it uses. Red Bull won four F1 championships in a row up to 2013, and Ghosn says that in F1 “you have the honour to be forgotten when you win and highlighted when you lose.”

Renault hope that electric racing will deliver technology benefits to its road cars, and Patrice Ratti, head of Renault Sport and Technology, says they have already learned from Formula E how to use software to manage energy better. “In a few years, we will have three to four times the range [in road cars] and the anxiety will go away,” he says. How long is a “few years”, I ask. “Maybe five to 10,” he says.