Request ID: FOI-2205-2324 Date published: 12 October 2023
You asked
I am writing to formally request the evidence supporting the CCO2 hypothesis.
1) All research, reports and studies conducted by your department or relevant authorities regarding the detrimental effects of carbon dioxide (CO2) on the enviroment. Specifically I seek evidence that unequivocally demonstrates the harmful impact of CO2 emissions and their relation to air quality degradation.
2) Detailed documents explaining the methodology and calculations used to determine the threshold for excessive CO2 levels post-photosynthesis and ocean absorption. Please provide any specific evidence or studies used to establish this threshold.
3) Comprehensive information concerning the measures planned to contain and maintain clean air over the designated region. Please include specifics on mechanisms or strategies proposed to achieve this goal and any research or analysis justifying their effectiveness.
4) A documented analysis of the amount of clean air that remains within the established region after implementation of the ULEZ scheme and how this is measured or determined. Please include any supporting evidence or studies that validate these measurements.
5) Please explain, using scientific reasoning, how a charge of £12.50 helps to reduce CO2 levels.
6)Please explain, using scientific reasoning, how much CO2 is produced by the one vehicle that does not meet the ULEZ standard and what effects if any this would have if 9 out of 10 cars meet the standard.
We answered
TfL Ref: 2205-2324
Thank you for your letter received by Transport for London (TfL) on 15 September 2023 addressed to D Milton asking for information about the ULEZ scheme.
Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. You asked for:
1) All research, reports and studies conducted by your department or relevant authorities regarding the detrimental effects of carbon dioxide (CO2) on the environment. Specifically I seek evidence that unequivocally demonstrates the harmful impact of CO2 emissions and their relation to air quality degradation.
2) Detailed documents explaining the methodology and calculations used to determine the threshold for excessive CO2 levels post-photosynthesis and ocean absorption. Please provide any specific evidence or studies used to establish this threshold.
3) Comprehensive information concerning the measures planned to contain and maintain clean air over the designated region. Please include specifics on mechanisms or strategies proposed to achieve this goal and any research or analysis justifying their effectiveness.
4) A documented analysis of the amount of clean air that remains within the established region after implementation of the ULEZ scheme and how this is measured or determined. Please include any supporting evidence or studies that validate these measurements.
5) Please explain, using scientific reasoning, how a charge of £12.50 helps to reduce CO2 levels.
6)Please explain, using scientific reasoning, how much CO2 is produced by the one vehicle that does not meet the ULEZ standard and what effects if any this would have if 9 out of 10 cars meet the standard.
We can advise that a variety of environmental research reports have been published via the following link to our website: https://haveyoursay.tfl.gov.uk/cleanair
Earlier this year, a report was also published by the Mayor’s Office, which shows that harmful pollution emissions have reduced by 26 per cent within the expanded ULEZ area - compared with what they would have been without the ULEZ coming into force.
Furthermore,six months on from the ULEZ expansion and over a year on from the enforcement of tighter LEZ standards, data indicates that these schemes are having a significant impact on the number of older, more polluting vehicles seen driving in London and the levels of harmful pollution Londoners are exposed to:
A bigger share of vehicles in London are cleaner. Six months after the launch of the ULEZ expansion nearly 94 per cent of vehicles seen driving in the whole zone meet the strict ULEZ standards on an average day, up from 87 per cent in the weeks before the zone expanded and up from 39 per cent in 2017 when impacts associated with the ULEZ began. The compliance rate on boundary roads is 90 per cent and the compliance rate in outer London is 85 per cent.
There are fewer older, more polluting vehicles in the zone. There were 67,000 fewer non-compliant vehicles in the zone on an average day compared with the period right before the ULEZ expanded, down from an average of 124,000 daily vehicles. This is a reduction of 54 per cent.
The Low Emission Zone continues to have an impact. Large and heavy vehicles, which fall under the London-wide LEZ, have a compliance rate of 96 per cent, up from an estimated 48 per cent in February 2017.
There has been an overall reduction in vehicles and traffic flows in the zone. Overall, there were 21,000 fewer vehicles seen in the zone on an average day (a reduction of 2 per cent) and early estimates suggest traffic flows are around 2 per cent lower than the weeks before the expansion launched. However, many factors are currently affecting traffic trends in London and we will continue to review the data to better understand the impact of ULEZ expansion in the longer term.
Drivers are ditching diesel cars. On average there were 44,000 fewer diesel cars driving in the zone each day – a 20 per cent decrease since the weeks before the ULEZ expanded.
This means people in the zone are breathing cleaner air. The amount of pollution in the air, the concentration, is what ultimately impacts people’s health. Harmful NO2 concentrations alongside roads in inner London are estimated to be 20 per cent lower than they would have been without the ULEZ and its expansion. In central London, NO2 concentrations are estimated to be 44 per cent lower than they would have been. This decrease in concentrations close to roads would have also led to reduced air pollution in locations away from traffic.
The air is also cleaner on the boundary. All monitoring sites on the boundary of the expanded zone have seen reductions in NO2 concentrations, with an estimated 17-24 per cent reduction in pollution on the boundary compared to a scenario without the ULEZ’.
However, we can advise that to answer your request is being refused under regulation 12(4)(b) of the EIR on the grounds that it would be “manifestly unreasonable” to comply in full. There is no single source of information within TfL from which to source this data and documentation in the granular detail you are seeking, as they are not held in a single suppository from which they could be extracted, reviewed and collated accordingly.
The use of this exception is subject to a public interest test, which requires us to consider whether the public interest in applying the exception outweighs the public interest in disclosure. We recognise that the release of information would promote accountability and transparency in public services and also help address concerns about this project. However, the time it would take to provide the information you have requested would divert a disproportionate amount of our resources from its core functions and on balance we consider that the public interest currently favours the use of the exception.
We will consider your request again, if you are able to narrow its scope so that we can more easily locate, retrieve and extract the information you are seeking.
If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely
Jasmine Howard FOI Case Officer FOI Case Management Team General Counsel Transport for London
