For example, this year in America, 1.5 million trucks were already sold through July. In China, the world’s biggest auto market with 21 million in sales last year, less than 330,000 pickups sold in all of 2015.

But now, thanks to new rules in four Chinese provinces that allow previously-banned pickup trucks to drive on city streets, pickup sales could explode over the next few years.

See also: Toyota Cuts Its Full-Year Forecast in the Face of a Stronger Yen

Pickup sales for the Chinese carmakers were up 36% in June from the year before, according to Bloomberg. Chinese brands like Great Wall are releasing new models as foreign brands Toyota (TM) and Ford (F) eye the market, and Ford said it would officially bring its bulked-up F-150 Raptor to China starting next year, though you can already spot quite a few in affluent areas of Chinese cities, thanks to a thriving gray market.

Still, the rising popularity of trucks isn’t universally welcomed. China is the world’s largest emitter of carbon emissions, and even though government policy has supported electric vehicles, consumers keep clamoring for bigger vehicles, making the country’s goal of reducing emissions and clearing city smog a tougher order.

Rising pickup sales won’t make things easier.