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A few things standout to me from the article. 1. London when the ULEZ was brought in was already a lot less polluted than historically.Are there gains from tha
by graemep 2mo ago
A few things standout to me from the article.
1. London when the ULEZ was brought in was already a lot less polluted than historically.Are there gains from that? London was not that bad by global standards.
2. This was followed by the benefits of COVID lockdowns (not a phrase often used!) as pollution dropped much further.
3. Is this effect even across London? Suburbs vs centre, different types of housing etc.? I grew up a the edge of London and the difference in pollution was visible (i.e. you did not need instruments to see signs of it).
4. There was also a reduction in sales of diesel cars which had been heavily encouraged (because of lower CO₂ emissions) in previous decades.
5. As the articles notes, there have been a lot of other changes at roughly the same time. It only mentions one, but there have been significant lifestyle changes, so a lot of potential confounding variables.
- dabinat 2mo agoWouldn’t most of those effects also be in the control group too?
- graemep 2mo agoMuch smaller place and starting from a better baseline so they would not have experienced the same changes.
- foven 2mo ago1. Less than historically still has a quite high baseline compared to after ULEZ - if it was more polluted, presumably the change seen here would be more dramatic. 2. Definitely kickstarted it, but we're looking at taking that impact and continuing it for some 5 years after covid ended now. 3. You can look at the ULEZ map and it really covers everything but the outer tube line suburbs [1]. 5. The control group in Luton, presumably, has the same lifestyle changes - it's not that far away (about 30 miles), so it is as close as you can get to a one to one comparison, not accounting for the fact that Luton is likely to be more deprived than London (especially in the council estates, which have horrible reputations). [1] - https://tfl.gov.uk/ruc-cdn/static/cms/images/ulezdetailedmapgif.gif https://tfl.gov.uk/ruc-cdn/static/cms/images/ulezdetailedmap...
- graemep 2mo ago1. yes, but there was probably a bigger gain before. Confirmation would be good. 2. does the study separate impact during lockdown from after? 3. my question is whether it had the same impact everywhere. I would guess very much not. 5. the impact of those changes might not be the same from a much better baseline, nor are lifestyle changes the same in a big city and a small town.
- 7952 2mo agoParticulate pollutant levels decay exponentially and have a substantial drop off with distance. So levels across a large area (like London) are not the whole story.
- graemep 2mo agoYes, I am not claiming they are an alternative explanation by themselves, but an example of changes other than the ULEZ.