Oh how the French and British deal so differently with similar problems. The French were hit by the smog first. Diesel engines appear to be a large part of the cause and the French answer seemed to be to ban 50% of the cars from driving into or about Paris when the smog was at its worst. Diesel engined cars in France are apparently very popular and no government there has so far risked the anger of supporters and voters generally by enacting legislation to reduce the popularity of diesel cars. Furthermore tax and duty on Diesel fuel in France is very low in comparison to the tax on petrol and again the governments of the day both left and right seem disinclined to alter the status quo in that regard.
In England when at first the smog seemed to be a French problem rather than one for this side of the channel there was much comment in the newspapers about what our French neighbours should be doing to reduce that type of pollution. Banning 50% of the cars seemed to me to be a good immediate step however. Then the problem arrived in the UK and the government, news papers TV radio etc here did what they are all excellent at in C21, namely talked and commented on what might be done what was being done and what was not being done but actually unlike our French neighbours did nothing.
The reality is that since so many branch railway lines were closed in the 1960s as a consequence of the 'Beeching' report on British Railways, the use and ownership of motor cars in the UK has risen dramatically. Arguably private motor car use would have increased substantially irrespective of Dr Beeching as people have become wealthier over the years. Nonetheless the acceptance of that report and the alacrity with which it was acted on were serious mistakes. Even if that is a little harsh as the risk of serious pollution was not really an issue in the 1960s especially after the London pea souper fogs of the 1950s had been eradicated, the need to reverse its effects has been clear for all of C21 if not earlier.
The dreadful smog and pollution reappearing in C21are in my view are wake up calls to us all to the effect that easy and still comparatively cheap access to or ownership of personal motor cars, need in the best interests of the planet and its peoples, sadly, to be curtailed.
In the UK the government is so sensitive to the electorate that the hikes in fuel taxes have been frozen for some while. Short term gains in money and convenience for many are alas risking pollution problems the world over. What needs to be done in the UK is for large sums to be spent on increasing public transport capacity. More trams hybrid engined buses, trains and trainlines need to be built and tax on car fuel substantially hiked and if necessary hiked again to pay for that. However such action takes political courage...
The same problem affects aviation fuel except that there the outcome is that there is generally no tax at all on aviation fuel - quite absurd in my humble opinion if not ultimately dangerous for life on this planet.