stuttgartmetal said:
You could see the smog very vividly 20 years ago if you worked in a tall building in Croydon. It is just much, much worse now; but it has been a problem for far longer than people have
officially cared about it. Why did nobody care about it then : the pan-European fixation with eliminating CO2 emissions above all else pushed governments to set tax to encourage low CO2 vehicles - specifically diesels - and nobody stopped to consider the consequences of a massive increase in the amount of diesel exhausts on the breathable air in densely populated areas.
They were all too busy not saving the planet (as Europe doesn't actually produce a drastic proportion of global CO2 to begin with) to stop and consider saving the lungs of their own people. But it wasn't and isn't a purely UK issue - it is basically all of Western Europe. And while this was all going on, nobody stopped to consider that you couldn't sell diesel private cars to the Americans because they couldn't be made to pass the legacy of 1970s smog legislation. Until they tried fiddling the tests. And got caught. Then people noticed.