Just two weeks after France said it will no longer allow the sale of gas- and diesel-powered autos after 2040, the United Kingdom has followed suit. In addition, the UK announced it is also exploring ways to tax the dirtiest vehicles on the road as a way to lower current air pollution levels in the most-affected local areas. About half of all cars registered in the UK each year are diesel-powered; electric and hybrid vehicles, although a growing market, still represent a tiny fraction of all new cars sold there. Experts predict that should start to shift in the mid-2020s as prices become more competitive.