Tuesday, 19 May 2015

Should diesels be banned from London's streets?

It is estimated that diesel vehicles are responsible for around 90 per cent of road based transport emissions.

That is the figure quoted by the Mayor in response to a question from John Biggs AM (Question No: 2014/3701). With the huge health impacts due to air pollution and possible enforcement coming from the EU the need for action is greater than ever.

The strategy from the mayor seems to be a combination of improving the standards of vehicles generally and banning the most polluting from central London. A complete ban seems off the table due to EU single market rules, but given the challenge of meeting the EU's air quality standards will Boris' plan be bold enough?

Ultra Low Emission Zone proposed

ULEZ will require most vehicles to meet a Euro 6/VI diesel standard (or an equivalent Euro 4/IV for petrol vehicles). For heavy vehicles, Euro 6 will reduce NOx emissions by between 80 and 90 per cent compared to Euro 5/V diesel vehicles.

The contrast between the new and existing standards shows the disproportionate pollution caused by a legacy of dirty diesels which will affect London's air quality for years to come. Even in the current Low Emission Zone (LEZ), 45,832 penalty charge notices were issued in 2013 for vehicles not meeting the current low standards, over 800 every week!

Many of the buses which are controlled by the mayor are currently only operating to the Euro III standards set over a decade ago, emitting ten times the NOx and particulates of Euro VI vehicles.


In the last year London have been running over one hundred Euro II buses and almost two thousand unimproved Euro III buses. That amounts to more than one in five of our buses emitting high levels of air pollution and contrasts with only 14 buses at the cleaner Euro VI standard.

Boris wants the entire fleet to meet the Euro IV standard "for these emissions" by 2015. The cynic in me would add that "for these emissions" means retrofitted Euro III buses count so we won't actually have fully compliant Euro IV standard buses. Therefore this means is retrofitting the remaining Euro IIIs and scrapping the handful of Euro II relics.

I think it's also worth asking that given the size of the problem and the importance the Mayor has placed on reaching Euro six, will achieving Euro four achieve the scale of improvement we need?

Buses in operation by Engine Type, the data:

  • Euro VI - 14
  • EEV * - 853
  • Euro V - 3,151
  • Euro IV - 1,683
  • Euro IIIs retrofitted with SCR** - 1,017
  • Euro III - 1,917
  • Euro II - 121
Total - 8,756

* EEV stands for enhanced environmentally-friendly vehicle.
** Euro III buses fitted with selective catalytic reduction which meet the Euro IV standards for particulate matter and nitrogen oxides.

Licensed Taxis

Data shows over half of taxis are currently at Euro 3 engine standard and currently there are only a handful of electric and hydrogen taxis operating in London. However Boris has said from 2018 all newly licensed taxis will have to be zero emission.

Similar to the buses, it seems we will be living with a legacy of older highly polluting vehicles for many years to come. Is this going to be fast enough or will this need to be replaced with a more ambitious plan to provide clean taxis for London?

More help needed?

In addition to these measures Boris says he has lobbied Government for a change to fiscal incentives (tax) and proposed a national diesel scrappage scheme to reduce the number of diesels on our roads.

Following the big Client Earth win on air quality, it seems likely Boris will need to review his plan to see if he can achieve more faster.

In fact this will be one of the first things Boris is asked when he starts back at Westminster City Hall.