The govenments banned pure diesel and Petrol cars from 2040, so it's not going to be that immediate, but as cars switch over to electric/hybrid cars, this means that demand for oil drops, and that means that buyers start to dictate the price, not sellers, so the price starts to drop, and then accelerates as those countries that are heavily reliant on oil revenues have to produce more at the cheaper price to get the revenue they want, and that extra supply pushes the price down further. Venezualla is already in the shyte, and Russia is struggling as well, althogh part of that's from sanctions. Saudi Arabia is having to dip into reserves, and is about to put the oil companies on the stock market, possibly before they can run out of revenues from oil. And the price is currently about $50 a barrel. If it gets down to $20, some economies will just crash, and could start a flood of emigrants leaving the sinking ship.