Authors: Julie Vaughan, Senior Associate, Environment and Helena Thompson, Associate, Planning and Environment, London

This blog gives an overview of the current position on air quality following the recent ClientEarth (No.2) court decision regarding DEFRA's air quality plan. In this blog we will consider:

  1. the ClientEarth (No.2) decision
  2. Sadiq Khan's approach
  3. new domestic legislation?
  4. impact on Heathrow expansion
  5. impact on development
  6. Brexit

Around 9,400 deaths in London are attributed to air pollution from nitrogen dioxide and particulates, whilst across the UK the effects of such pollution result in the equivalent of 23,500 deaths each year. The Air Quality Directive 2008 sets out the limit values for particular pollutants, including nitrogen dioxide, for the protection of human health. 40 out of 43 zones in the UK are in breach of the limit values for nitrogen dioxide. Where the limit values are exceeded, the Government is required to prepare an air quality plan which includes measures to achieve compliance within the shortest possible time.

ClientEarth (No.2) decision

The legal campaign group ClientEarth recently won their second case against the Government regarding air quality in the UK. ClientEarth had argued that DEFRA's national air quality plan published in December 2015 (to bring pollution levels within the legal limits) was insufficient and unambitious.

On 2 November 2016, Justice Garnham held that air quality measures had to be (i) effective in achieving the air quality limits and (ii) achieve them in the shortest possible time, and DEFRA's air quality plan was neither.  Justice Garnham also rejected DEFRA's justification that its original, more extensive plans were thwarted by the Treasury due to cost. He held that, although measures should be proportionate, the Government should not have any regard to cost in achieving compliance where one route could produce quicker results than the other, even if more expensive.

DEFRA therefore has to achieve compliance by the soonest date possible, and we wait to see how and what DEFRA will do in order to comply with this judgment.

Sadiq Khan's approach

Air quality is one of the Mayor of London's, Sadiq Khan's, top priorities. He supported and intervened as an interested party in the ClientEarth (No.2) case. His current consultation sets out statutory proposals for an emissions surcharge, the bringing forward of the introduction of the ultra low emission zone ("ULEZ") by one year to 2019 and the extension of the ULEZ London wide (for HGVs) up to the North and South Circular roads (for all vehicles). This consultation closes on 18 December 2016.

Following the ClientEarth (No.2) ruling and in a letter to the Secretary of State ("SoS") on 7 November 2016, Sadiq Khan has called for further urgent action on air quality, including a national diesel scrappage scheme, reforms to the current vehicle excise duty (which promotes purchase of diesel cars), additional powers for local authorities to manage emissions, greater funding, and a new Clean Air Act.

New domestic legislation?

Sadiq Khan suggests that a new Clean Air Act would provide an overarching framework for air quality, allowing the Government to regulate all emission sources, not just road transport, and giving local authorities more powers to tackle this issue. ClientEarth has called for such a Clean Air Act to consolidate air pollution laws, guarantee the right for the public to access the courts to enforce its provisions, and set a national outline for effective Clean Air Zones which phase out diesel and speed up the conversion to zero emission transport.

Separately, the Clean Air Bill, a Private Member's Bill, is to have its second reading in the House of Commons on Friday 16 December 2016. This Bill focuses on urban air quality targets relating to diesel emissions, including the establishment of low diesel emissions zones and pedestrian-only areas, and promotion of urban public transport powered by electricity or hydrogen and the development of sustainable public, private and commercial transport.

Impact on Heathrow expansion

The ClientEarth (No.2) ruling could be a thorn in the side for the Heathrow expansion, as the analysis of the air quality impacts relies heavily on the data and mitigation measures outlined in DEFRA's insufficient December 2015 air quality plan. Once the national air quality plan is revised, this will need to be taken into account. Additionally, the Department for Transport's ("DfT") policy briefing note recognises that new international evidence on vehicle emissions forecasts has since been released, so further work is needed.

Although the Transport Secretary, Chris Grayling, has said that the new runway is "deliverable within air quality limits", Sadiq Khan's recent letter to the SoS states that a third runway is not compatible with achieving and sustaining legal compliance with toxic emission limits. To ensure legal compliance on air quality, DfT will lay before Parliament and consult on a draft Airports National Policy Statement that will outline measures to be considered when Heathrow is preparing its development consent application. Whether the Heathrow expansion can achieve legal compliance is key to the future of the project, as the DfT has confirmed that "development consent will not be granted unless the Secretary of State is satisfied that the scheme would comply with air quality legal requirements".

Impact on development

Currently, air quality is relevant to a planning decision where: a) development is likely to affect the air quality in a poor air quality area, b) adversely impact air quality strategies and action plans (which will include the revised air quality plan), and/or c) lead to a breach of EU legislation. It is possible that a stricter and more cautious approach in planning decisions could follow on from the recent ClientEarth (No.2) decision and once DEFRA publishes a revised action plan.


The think-tank IPPR published a report on the same day as the recent ClientEarth (No.2) judgment, which confirms our view that the UK's departure from the EU means that legislation on air pollution limits could be repealed and standards reduced.  However, following the recent speech by the Prime Minster regarding the conversion of EU law existing at the point of Brexit into domestic law, it is likely that the current legislative situation will, at least initially, remain relatively the same – see our recent blog here.

For more information please contact:

Julie Vaughan
Julie Vaughan
Senior Associate, Environment, London
+44 20 7466 2745
Helena Thompson
Helena Thompson
Associate, Planning and Environment, London
+44 20 7466 2778