UK Official Says Encouraging Diesel Cars To Lower Carbon Was 'Wrong'

For at least 20 years, diesel cars have been much more popular in Europe than in the United States.

Because diesel combustion is more efficient than gasoline combustion, the engines help drivers save money on fuel--and produce lower emissions of greenhouse gases.

MORE: Diesel Pollution In London Makes Air Worse Than Beijing For Nitrous Oxides

However, European countries have only recently adopted a similar strict level of emissions standards to the U.S.

That's led to public concerns over air quality, due to the high levels of nitrous oxides (NOx) and other harmful substances from diesel exhaust produced by engines without modern emission controls.

Up through last year, the diesels sold throughout Europe that would not have been legal to sell in the U.S. for most of a decade.

The consequences of such a large fleet of diesel cars recently led British shadow environment minister Barry Gardiner to conclude that the country's strategy for reducing carbon emissions had been flawed.

A policy that based vehicle taxes on carbon-dioxide (CO2) emissions was wrong, he said in a recent television interview (via Motoring Research), because it encouraged more people to buy diesel cars.

ALSO SEE: London To Levy Additional Charge On Older, Higher-Emitting Cars By 2020

He claimed lawmakers didn't anticipate the negative health effects of the decade-long increase in diesel exhaust emissions as they moved to cut CO2.

While diesel sales rates vary significantly among the different countries of the European Union, the U.K. too has historically had a high percentage of diesel cars on its roads.

And in many EU countries, diesel fuel is tax-advantaged, meaning that it's cheaper per gallon than gasoline.

Increased fuel efficiency and cheaper fuel together easily offset the higher cost of diesel engines versus gasoline engines of equivalent power.