As global leaders meet in Poland to hammer out details about how to meet Paris Climate Accord targets, a new study shows that European automakers aren't introducing electric cars nearly fast enough to meet European standards—and the delay could cost them.

The European Union has set the strictest limits on carbon-dioxide emissions from cars anywhere on the planet: 95 grams of CO2 per 100 kilometers, which would require cars there to average the equivalent to about 57 miles per U.S. gallon.

And most of Europe's automakers aren't meeting that standard.

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A new study published by PA Consulting, a global consulting firm based in London, shows that 8 out of Europe's 13 largest automakers have fallen behind and will face serious fines for missing the standard according to a report in the Times of London (subscription required.) The automakers include, Volkswagen, Ford, Fiat Chrysler, Mazda, Hyundai, BMW, Daimler, and the PSA Group.

The fines take effect in 2021 and will vary by how much each automaker has missed the targets. Volkswagen, Europe's largest automaker, faces the largest fines of almost $1.6 billion (1.4 billion euros), equal to about 10 percent of the company's annual earnings.

French automaker PSA, parent of Peugeot, Citroen, and GM's former European arm, Opel, faces a fine of $682 million, about 20 percent of its annual earnings. 

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Volkswagen has announced serious efforts to build and sell electric cars, investing $11 billion to build electric cars by 2023 and develop up to 10 new electric cars.

Even with such efforts, though, electric car sales remain slow in Europe, amounting to just 0.6 percent of the market in Britain in June, for example. Another study showed that emissions of CO2 from new cars in Europe rose for the first time last year, as automakers focused on reducing emissions of nitrogen oxides from diesels over reducing CO2 emissions.

Through a joint advocacy organization, the Society of Motor Manufacturers and Traders, automakers have said the standards are too rigid and called for more public charging stations to make electric cars easier for consumers to choose.