Weasling on Diesels?

The first thing to admit is that I have a relatively new diesel car. I have noted, however, the growing concern about the dangers of their emissions (notably nitrous oxides and particulates) to human health, especially at busy intersections in city centres (where levels of pollutants frequently exceed permitted levels), leading to  plans to ban diesel vehicles from these locations. It is interesting to consider the changing advice on motor transport and the effects on air quality (www.air-quality.org.uk/26.php). Diesels were initially viewed as superior to petrol vehicles, as they were more efficient users of fuel (more Km per litre) and generated less carbon dioxide (a major 'greenhouse' gas). They also never had to use lead (dangerous to neural health) in their fuel as an anti-knocking agent. One should also note that diesels vary in terms of the effectiveness the devices fitted to their exhausts to deal with emissions, suggesting that some diesels are worse polluters than others. There has been talk of a scrappage scheme for diesels and their replacement by hybrid or electric vehicles. I would merely note that scrappage and replacement building would generate a lot of emissions and that even electric cars would not be especially helpful to climate change if generation and distribution of the needed electricity did not carefully consider carbon dioxide release.