5th August 2023

London’s Ultra-Low Emissions Zone (ULEZ) was brought in to reduce air pollution because of the damage it was doing to children and legal requirements to reduce nitrogen dioxide levels and other pollutants. But much of the commentary following the Uxbridge and South-Ruislip by-election has assumed that ULEZ is not just a public health policy but also a green climate policy. Many commentators, and perhaps also the government, have proceeded as if Labour’s failure to win Uxbridge because of ULEZ expansion means the Conservatives are likely to hold on to more seats at the next general election if they weaken their climate change mitigation policies.

But how much are ULEZ and climate change mitigation connected in the public mind?

Since the Net Zero law was first announced, Deltapoll has annually been asking representative samples of people in Britain the following question.

“Reducing UK greenhouse-gas emissions to net-zero involves heavily cutting the use of fossil fuels and finding ways of taking any remaining greenhouse-gas emissions out of the atmosphere. Do you approve or disapprove of changing the law to require the government to reduce UK greenhouse-gas emissions to net-zero by 2050?”

Table 1: Approval of the Net Zero by 2050 Law

Net-zero by 2050 law:	2019	2020	2021	2022	2023
	%	%	%	%	%
Strongly approve	28	27	26	24	22
Approve	32	38	37	32	37
TOTAL APPROVE	60	65	63	56	59
Neither approve nor disapprove	22	22	22	26	24
TOTAL DISAPPROVE	8	7	8	8	11
Disapprove	5	5	5	5	7
Strongly disapprove	3	2	4	3	5
Don’t know	10	6	6	10	6
(N)	(2016)	(1545)	(1560)	(1550)	(1556)

Source: Deltapoll, June 2019, March 2020, Nov 2021, April 2022, and July 2023.

Table 1 shows that despite the Covid pandemic, support for the Net Zero law held steady through 2020 and 2021. Shortly after the February 2022 Russian invasion of Ukraine, there was a dip in approval, from 63% in 2021 to 56% in March 2022, perhaps related to the mounting cost-of-living. However, at 59%, approval this year is now basically what it was in June 2019. Overall, approval of the Net Zero law is remarkably stable despite evidence that attitudes to Net Zero are only weakly related to beliefs about climate science.

Attitudes to ULEZ expansion will be highly correlated with attitudes to Net Zero if the same kind of people that approve of the Net Zero law also support ULEZ expansion. Between 28^th and 31^st July 2023, Deltapoll asked a representative sample of adults in Britain what they thought of both policies, with the results in Table 2. Since many know little about what ULEZ is, respondents were told:

“The Ultra-Low Emission Zone (ULEZ) is an area in London where a fee is charged when driving vehicles, such as cars, motorcycles, some vans, specialist vehicles, and minibuses, that do not meet emissions standards. The zone covers all areas within the North and South Circular Roads. From August 2023, Transport for London (TfL) has announced that the Ultra-Low Emission Zone (ULEZ) is expanding to include all 33 boroughs of Greater London, which in some places will border the M25.”

Table 2: Approval of ULEZ expansion by Approval of the Net Zero Law

%	Support for ULEZ Expansion	Other	Total
Approve Net Zero law	30	28	59
Other	5	37	41
Total	35	65	100

Source: Deltapoll, July 2023. N=1556

Very few, just 5%, support ULEZ expansion but do not approve of the Net Zero law. Fully two-thirds, 67%, either support both or support neither. So, attitudes to the two policies are strongly correlated. The policies divide people in similar ways.

So perhaps it is justifiable to draw political lessons for climate policy from the controversy over ULEZ expansion and Labour’s failure to win the Uxbridge and South Ruislip by-election?

Not so fast. Overall support for ULEZ expansion, at just 35%, is much lower than the 59% approval for Net Zero. Just over a quarter, 28%, of adults in Britain approve of the Net Zero law but not ULEZ expansion.

Since Net Zero approval does not tell us much about levels of support for ULEZ expansion, trying to draw lessons about the popularity of climate change mitigation policies from a by-election focused on ULEZ expansion is unwarranted and risky.

Nonetheless, some argue that the Uxbridge result is important because it fits a broader pattern of research showing that support for environmental protection in general does not translate into support for taxes on environmentally damaging behaviour.

But the unpopularity of ULEZ expansion within Outer London cannot be explained by the small numbers who will have to pay the charge. Moreover, Table 1 includes adults across Britain, the vast majority of whom never drive into London. The corresponding figures for London are much the same. The low level of support for ULEZ expansion has practically nothing to do with having to pay the charge personally.

ULEZ as a climate policy as well as a public health policy?

For Inner London, ULEZ has been successful in reducing levels of nitrogen dioxide and other damaging gasses. Since the charges are heavily concentrated on the oldest and most polluting vehicles, they do nothing directly to discourage driving most petrol and diesel vehicles in London, limiting the scope for carbon reduction.

Nonetheless one aspect of Deltapoll’s survey allows us to assess whether ULEZ expansion is still seen as relevant to climate change.

For a randomly chosen half of the sample, Deltapoll asked about Net Zero approval and climate change beliefs immediately before asking about ULEZ. For the other half it was the other way round. For those who were not asked about ULEZ first, support for ULEZ expansion was just 28%. But for those who were asked the two climate change questions first, support for ULEZ was, at 41%, some 13-points greater.

That is a very large effect for a randomised question-ordering experiment. Simply telling people about what the Net Zero law involves and asking people about what they think about climate change increases support for ULEZ by 46%.

Sometimes random allocation is by chance uneven. Barely at all on this occasion, and further analysis controlling for socio-demographics and prior voting, all asked before either ULEZ or climate change, made no difference to the effect of the question ordering on attitudes to ULEZ.

The effect was not just for ULEZ expansion but also applies to levels of support for the existing ULEZ policy for Inner London.

What about the other way round? Did the question ordering affect attitudes to climate change? Not in any statistically significant or systematic way.

It seems that attitudes to climate change are not so easily manipulated, in keeping with the stability of approval for the Net Zero by 2050 law that we saw in Table 1.

The stability of the clear majority for, and tiny opposition to, the Net Zero law suggests there are political risks for politicians seeming to undermine it.

By contrast, the experimental results here suggest that the Mayor of London might increase support for ULEZ expansion by arguing it is a climate change mitigation policy as well as a clean air policy.

 

Stephen Fisher is Professor of Political Sociology at the University of Oxford.