Electric cars make up only a tiny fraction of the automobiles sold worldwide, but that will change quickly, according to an analysis by Bloomberg New Energy Finance.

By 2040, electric cars could make up 57% of all passenger car sales worldwide, the report found. That's up two percentage points from BNEF's 2040 projection last year. Electric vehicles will make up a similar percentage of light commercial vehicle sales in the United States, Europe and China within that time, BNEF predicts.

"We see a real possibility that global sales of conventional passenger cars have already passed their peak," said Colin McKerracher, head of advanced transport for BNEF.

Electric cars are coming close to matching gasoline- and diesel-powered cars in purchase price and they already cost less to operate. That means that electric cars will soon overtake internal combustion-powered cars as the more economical choice for consumers, according to the new report.

Over the next two decades, worldwide electric vehicle sales will rise from 2 million last year to 56 million by 2040, BNEF predicts. At the same time, sales of "conventionally powered" vehicles will fall from last year's 85 million to just 42 million globally.

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