From
https://www.thetimes.co.uk/article/pollution-charge-for-diesels-has-cut-citys-toxic-fumes-by-a-third-7vmf0wwst?shareToken=c4cb13264b46e8e695faa7f1bcae0 0af

Quote:
NO2 has fallen from 85 to 57 micrograms per cubic metre at the roadside in
central London since October 2017, when Sadiq Khan, the mayor of London,
introduced a £10 daily toxicity charge. The charge increased to £12.50 in
April as part of the capital’s Ultra Low Emission Zone (Ulez).

There were 13,500 fewer polluting cars driven into central London last
month compared with March, a reduction of 38 per cent, according to the
report by the Greater London Authority.

However, the level of NO2 in central London remains well above the legal
limit of 40mcg/m3 and almost a quarter of vehicles in the charging zone
breach the Ulez emissions standard. This is partly because diesel black
cabs are exempt from the charge.

The amount of traffic in central London has fallen by up to 9 per cent
since last year, suggesting that the introduction of the charge has
prompted some people to give up driving into the centre.

So, what we now need to know is would the level of NO2 drop below
the legal limit if Hackney Cab drivers all went over to a hybrid vehicle.

The second important piece of information is which vehicles and
drivers have now given up coming into central London. Anti-motor car
politicians always assume it's joy-riding motor car enthusiasts making
unnecessary journeys who have been repelled, but what if it's tradesmen
providing essential services who now refuse to serve inner London?

A third detail will not in any circumstances be made public: how do
the new levels of NO2 compare with those prior to London having a
Mayor?

On Mon, 21 Oct 2019 12:20:39 +0100, Robin9
wrote:


So, what we now need to know is would the level of NO2 drop below
the legal limit if Hackney Cab drivers all went over to a hybrid
vehicle.

It's happening anyway, as all new taxis in London are PHEVs. They're
now very common, and are refreshingly quiet, as well as clean.


The second important piece of information is which vehicles and
drivers have now given up coming into central London. Anti-motor car
politicians always assume it's joy-riding motor car enthusiasts making
unnecessary journeys who have been repelled, but what if it's tradesmen
providing essential services who now refuse to serve inner London?

I'd imagine that tradesmen still serve central London, but charge more
to cover the upgrade cost of their vans.


A third detail will not in any circumstances be made public: how do
the new levels of NO2 compare with those prior to London having a
Mayor?

Why do you think they wouldn't be made public? London mayors don't
have any ability to censor reports. Or do you think it's some grand
conspiracy involving Labour, Tory and coalition governments, and
Labour, Tory and independent mayors?

These are national figures going all the way back to 1987:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/796887/Air_Quality_Statistics_in_the_UK_1987_to_2018.pdf


Here's King's College's London series going back to 2008:
https://data.london.gov.uk/dataset/london-average-air-quality-levels

In message , at 09:41:30 on Mon, 21 Oct
2019, Recliner remarked:
From
https://www.thetimes.co.uk/article/p...iesels-has-cut
-citys-toxic-fumes-by-a-third-7vmf0wwst?shareToken=c4cb13264b46e8e695faa
7f1bcae00af

Quote:
NO2 has fallen from 85 to 57 micrograms per cubic metre at the roadside in
central London since October 2017, when Sadiq Khan, the mayor of London,
introduced a £10 daily toxicity charge. The charge increased to £12.50 in
April as part of the capital’s Ultra Low Emission Zone (Ulez).

There were 13,500 fewer polluting cars driven into central London last
month compared with March, a reduction of 38 per cent, according to the
report by the Greater London Authority.

Averaged over 20 hours a day that's 20 an hour. Over the whole of the
zone. One less polluting car every 3 minutes in the whole of London
doesn't pass my sniff-test for the claimed results.

However, the level of NO2 in central London remains well above the legal
limit of 40mcg/m3 and almost a quarter of vehicles in the charging zone
breach the Ulez emissions standard. This is partly because diesel black
cabs are exempt from the charge.

The amount of traffic in central London has fallen by up to 9 per cent
since last year, suggesting that the introduction of the charge has
prompted some people to give up driving into the centre.



--
Roland Perry

Roland Perry wrote:
In message , at 09:41:30 on Mon, 21 Oct
2019, Recliner remarked:
From
https://www.thetimes.co.uk/article/p...iesels-has-cut
-citys-toxic-fumes-by-a-third-7vmf0wwst?shareToken=c4cb13264b46e8e695faa
7f1bcae00af

Quote:
NO2 has fallen from 85 to 57 micrograms per cubic metre at the roadside in
central London since October 2017, when Sadiq Khan, the mayor of London,
introduced a £10 daily toxicity charge. The charge increased to £12.50 in
April as part of the capital’s Ultra Low Emission Zone (Ulez).

There were 13,500 fewer polluting cars driven into central London last
month compared with March, a reduction of 38 per cent, according to the
report by the Greater London Authority.

Averaged over 20 hours a day that's 20 an hour. Over the whole of the
zone. One less polluting car every 3 minutes in the whole of London
doesn't pass my sniff-test for the claimed results.

Well spotted — you're right. It turns out that the Times report missed out
a crucial word: 'daily'.

Quote:

- New report shows significant drop in air pollution plus 13,500 fewer
polluting cars being driven into the zone daily

- 77 per cent of vehicles in the zone now meet the clean emissions
standards

- Report on first six months of scheme confirms no increase in pollution
around the ULEZ boundary

New figures show there are now 13,500 fewer polluting cars being driven
into central London every day and a significant drop in harmful air
pollution, since the Mayor introduced the Ultra Low Emission Zone six
months ago.

…

Since introducing the ULEZ new data reveals that:

- Roadside nitrogen dioxide (NO2) pollution has reduced by 36 per cent in
the zone. This is measured from February 2017 to September 2019, to reflect
when the Mayor publicly confirmed the Toxicity Charge (T-Charge) – the
predecessor to the ULEZ - and people started to prepare for the schemes.
Analysis in today’s City Hall report estimates that the reduction in NO2
pollution solely attributable to the ULEZ is 29 per cent*.

- None of the air quality monitoring sites located on ULEZ boundary roads
have measured an increase in NO2 pollution levels since the scheme was
introduced in April 2019.

- From March to September 2019 there was a large reduction in the number
of older, more polluting, non-compliant vehicles detected in the zone: some
13,500 fewer on an average day, a reduction of 38 per cent.

- 77 per cent of vehicles now in the zone now meet the ULEZ emissions
standards. This is much higher than the 39 per cent seen in February 2017
and the 61 per cent in March 2019 .

- NOx emissions from road transport in the central zone are now 31 per
cent (200 tonnes) lower than if the scheme was not in place. This is ahead
of schedule to meet the 45 per cent NOx emission reduction expected in the
first year.

- There was a reduction in traffic flows in central London in May and
September 2019 of between three and nine per cent when compared to 2018,
indictaing the wider benefits of the ULEZ in encouraging people to switch
to walking, cycling or using public transport**

- The ULEZ is also tackling the climate emergency. After six months,
carbon dioxide emissions from road transport in the central zone are four
per cent (9,800 tonnes) lower than if there was no scheme. When compared to
2016 levels, this equates to an expected 13 per cent reduction in carbon
dioxide emissions if the current compliance rates continued over the course
of this year.

…

* note: 29 per cent reduction is at roadside sites in the central zone,
comparable to a “no ULEZ scenario�
** note: traffic flows may also have been influenced by other changes,
such as the removal of the exemption for private hire vehicles from the
congestion charge.


From
https://www.london.gov.uk/press-releases/mayoral/ulez-reduces-polluting-cars-by-13500-every-day

I should have made my point more clearly. I don't believe either
Sadiq Khan or TfL will release information which facilitates a
comparison of London's air quality today with what it was in
the year before we had a Mayor and TfL.

Obviously I am aware they do not have the power to prevent reports
from Government bodies or research institutions from reaching
the general public.