London takes lead on clean air

Photo: Garry Knight (CC BY 2.0)

Will Sadiq Khan rise to the Climate Emergency challenge, asks Tim Root?

When announcing his plan to extend the Ultra Low Emission Zone (ULEZ), Sadiq Khan said: “we need to further reduce emissions from vehicles in London… The climate emergency means we only have a small window of opportunity left.” 

He is well aware of the serious consequences of failing to cut greenhouse gas emissions enough. City Hall noted the nearly 500 additional deaths in London due to 19 days of heatwaves in 2020, and that many places, including nearly half of London hospitals and one in five schools, will be at risk of flooding if temperatures continue rising. Analysis shows that areas with Black, Asian and minority ethnic populations of more than 50% are more likely to face the highest climate risk in London.

Statutory advisers, the Committee on Climate Change, recommend a 37% cut in UK car emissions by 2030. However, the mayor’s team calculates that expanding the ULEZ to the whole of London would reduce CO2 emissions in outer London only by between 135,000 to 150,000 tonnes, a cut of only about 6.7%. This is because the ULEZ criteria take no account of CO2. In ordinary circumstances, extending the ULEZ to the whole of London would be a commendable step forward. However, when considering the climate emergency, it is seriously inadequate. Already, half the world’s population is suffering severe water shortage at some point each year due to climate breakdown. The Intergovernmental Panel on Climate Change states that, at present, “the poorest vulnerable populations” are suffering worst. It is vital that cities take strong action promptly. Sadiq Khan, as chair of the global group C40 Cities, could ensure that London sets a great example for other world cities to follow.

Transport is the policy area over which the mayor has the most direct control. Before the pandemic, vehicle miles in London increased by 8.6% from 2016–2019. Mileage has now returned to pre-pandemic levels, so the trend of increasing emissions could well resume, particularly now that the government has responded to the fuel price rise by cutting fuel duty. The mayor needs to focus on the survey findings that about 42% of miles travelled in England are for leisure, and that higher income families drive much further than drivers in poorer households. Therefore, greenhouse gas emissions from cars could be substantially reduced without causing deprivation. Transport for London found that only one trip in seven by a driver involves any thought about which mode of travel to use, with only 4% giving this serious thought in regard to a specific journey. However, many car journeys could fairly easily be undertaken by other means; 35% of all London car trips are shorter than 2km. International research shows that even quite modest road user charges can stimulate a significant proportion of people to drive less.

Londoners are ready to drive less

Nearly two-thirds of Londoners think that “motorised transport” makes a large or very large contribution to climate change. Only one in six say they would not consider using public transport instead of driving. Seven out of eight say they are motivated to help prevent climate change.

However, encouraging people to drive less would be strengthened by convenient and affordable public transport. As the pandemic decimated Transport for London’s income, there is now the prospect of 9% cuts in tube services and up to 19% cuts in bus services. Moreover, average fares went up by 4.8% on 1st March, while other living expenses are rising steeply.  The best way the mayor can cut car emissions is to raise money from those drivers who can afford to pay, to reduce some of the public transport cuts.

To do this, the mayor could very soon include vehicles which emit well above the average level of CO2 in the current ULEZ. This could be enforced using the existing cameras and therefore would need no upfront investment, only a consultation, which would not be costly. 2018 statistics show that nearly one-sixth of UK cars emitted more than 171 grams of CO2 per kilometre.  I took a random sample of nine such cars which are not liable to pay the ULEZ charge. Their average price when new is 1.8 times that of the average new price of the 10 best-selling cars in the UK, and therefore they are probably nearly all owned by people with well above average income. If these cars were driven within the ULEZ about twice weekly, i.e. 100 times per year, each would pay £1,250 per year, totalling £201 million. This would double the current expected ULEZ proceeds (para 6.22). The extra income would also help to fund increases in the payments for low-income or disabled drivers to scrap particularly polluting cars, and for other relatively low-paid workers who need to drive, such as those in social care.

Expanding the ULEZ throughout Greater London would substantially improve air quality and provide major health benefits. However, the ULEZ gives drivers no incentive to limit their mileage once they have incurred the set daily charge. By contrast, per-mile road charging would be much fairer to those who need to make short journeys. The charge per mile would increase according to the emissions level of the car, the availability of public transport in that locality, and the congestion level at that particular time. Research undertaken for pro-motorist body the RAC found that drivers broadly support the principle of “the more you drive, the more tax you should pay”. Technology like that in smart phones, and also built into many cars, is already available for privacy-friendly smart road charging, and used in various places such as Washington state. At the very modest price of £0.08 per mile, smart charging for cars in London would raise about £1.14 billion per year, after exempting electric cars and cars driven by or for people with disabilities. This income would fairly soon fall, as miles driven reduced and drivers switched to non-polluting transport. But for a few years, substantial amounts would be raised to improve public transport and cut fares. With smart road charging, Sadiq Khan could go down in history as a trailblazer for climate protection, clean air, and affordable public transport.  

Please take part in the Mayor of London’s consultation starting this May, to say

  • Yes to expand the Ultra Low Emission Zone throughout London
  • London needs per-mile road user charging very soon to protect our climate and improve air quality.

More info on the mayor’s consultation, once it goes live, will be at


  1. I think the chap from Muswell Hill is about to discover that the “let’s all make life more difficult and expensive to save the bunnies” line won’t go well in 2022. Indeed, he might find some very angry people responding. A lot of homes will be cutting their fuel consumption out of sheer inability to pay. There is no virtue in playing greener-than-thou games right now.

  2. I think Paul Martin’s problem is that he has not quite grasped that we are the bunnies.

  3. The film ” Don’t Look Up ” is a perfect example of what we should NOT DO . We need to change for our grandchildren and their children’s sake and more importantly the future of everything that exist on this planet We cannot afford any short term views i belive .

  4. To paraphrase John Maynard Keynes, “in the long run we’re all dead”! No one dies of long-term effects but of actual happenings in the present – disease, accident or whatever. Governments need policies that will both work against global warming and this year’s floods and famines.

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