Of course that is not the story that the government want to put out and so they spin the facts to give exactly the opposite picture. Today scientists are able to measure levels so low that we would have been unable to detect them in the past and so they are able to set maximum limits at these levels and so use this as an excuse to persuade the public to support a ban on the fossil fuel engines and heating systems that have served us so well and cheaply for the past century. Instead they propose that we rely on electricity from wind and solar energy. This is nothing more than a pipe dream - a very expensive and unreliable one. When will they wake up?
Further reading on this here. And what about power stations that burn wood instead of coal? This report says they are as bad as millions of diesel cars.