Electric vehicles (EVs) are a powerful weapon in the world's battle to beat global warming, yet their impact varies hugely from nation-to-nation and in some places they pollute more than gasoline models, data analysis shows.

In Europe, where sales are rising the fastest in the world, EVs in Poland and Kosovo actually generate more carbon emissions because grids are so coal-reliant, according to the data compiled by research consultancy Radiant Energy Group (REG)...