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04 November 2016

727: Air quality judgment and implications for infrastructure projects

Today’s entry reports on this week’s High Court judgment on air quality.

The second most important legal case of the week has implications for infrastructure projects. (So does the most important one, but we might as well wait for the appeal to the Supreme Court that will be heard on 5-8 December possibly by all 11 justices (there being one vacancy)).

The case is the second challenge by ClientEarth, an environmental pressure group, to the government’s air quality plans. It first challenged them in 2011, and the case went all the way to the Supreme Court, then the Court of Justice of the European Union, before being returned to the Supreme Court and decided in April last year.

In that case the Supreme Court decided that air quality plans produced in 2011 by the government were inadequate and that revised plans had to be prepared and published by the end of that year. Accordingly, in December 2015, the government published revised air quality plans for each of the UK’s 43 zones and agglomerations. You will notice that the plans deal specifically with nitrogen dioxide, as that is the toughest pollutant to keep below the required thresholds.

The obligation under the ambient air quality directive is that if concentrations of certain pollutants in the air is still above set thresholds by 2010, then they must be brought within the thresholds as quickly as possible. The two main thresholds are that average concentrations of NO2 must be below 40 micrograms per cubic metre, and that NO2 cannot be higher than 200 µg/m3 for more than 18 separate hours across a whole year. London in particular has some way to go, as that hourly threshold was breached on 9 January this year.

This week’s judgment

ClientEarth challenged the December 2015 plans again for being inadequate and on Wednesday the High Court ruled in their favour, quashing the entire suite of plans. The judgment is pretty damning. The main points are as follows:

The government decided against some measures to combat pollution levels on grounds of cost, but the court ruled that effectiveness of the measures should outweigh cost (albeit conceding that some measures such as banning all cars from city centres were disproportionate in their effects and therefore need not be considered). Paragraph 50 of the judgment states:

‘The determining consideration has to be the efficacy of the measure in question and not their cost. That, it seems to me, flows inevitably from the requirements in the Article to keep the exceedance period as short as possible.’

Secondly, the government’s practice of only doing modelling every five years to see how each zone is getting on was considered too infrequent in this urgent situation. Apparently they decided the EU wouldn’t start fining the UK until 2020 so that’s when they were aiming to achieve the targets, rather than the requirement of as soon as possible.

Thirdly, the model used by the government, the ‘computer programme to calculate emissions from road transport’, or COPERT, significantly underestimated air pollution compared with real-world measurements, and there was evidence that the government knew that but carried on using it regardless.

The latest emission standard for vehicles, Euro 6, aims to limit NO2 emissions, and COPERT assumes that vehicles will in fact be 2.8 times over the limit. Depressingly, that is apparently too low an estimate and it should be four to five times. The judge concluded:

’86. [The air quality plans] identified measures which, if very optimistic forecasts happened to be proved right and emerging data happened to be wrong, might achieve compliance. To adopt a plan based on such assumptions was to breach both the Directive and the Regulations.’

The judge upheld ClientEarth’s case and quashed the entire suite of air quality plans. Further relief is being argued about next week.


The Government is going to have to do much more to combat air quality and fork out some serious money on it if it is not to find itself in the courts again. To me, the 2015 plans just seemed to be a parroting of local authority measures without adding very much to those, so it seemed pretty inevitable that they would be shown up as not achieving the targets as quickly as possible.

The issue of Brexit hangs in the air – if and when departure from the EU happens, will the deal allow us to alter our air quality obligations? Even if so, that wouldn’t go down very well with many people, including the Mayor of London, and might well be too much of a political hot potato to do.

As most air pollution is caused by vehicles on the road, this may give rise to problems with projects that involve a lot of vehicles using the road, including highway, and of more recent interest, airport projects.

The Airports Commission recommended Heathrow with the proviso that it should only be allowed to operate if it could do so without slowing down compliance with air quality targets (see page 11).

When taking its decision to endorse Heathrow, the government commissioned further air quality work to demonstrate that Heathrow could expand without slowing down compliance. That report uses the same model, COPERT, and indeed admits in its foreword on page 1 that it doesn’t even take the latest COPERT factors into account. If that is based on a significant underestimate of emissions from vehicles, it is difficult to see how it remains valid.

Indeed, the government announcement says:

‘a new runway at Heathrow is deliverable within air quality limits, if necessary mitigation measures are put in place, in line with the ‘National air quality plan’, published in December 2015.’

Well, that plan has just been quashed for inadequacy (although I note amusingly that a policy on page 228 of the London agglomeration plan is ‘No third runway at Heathrow’). The government goes on to say ‘The government will make meeting air quality legal requirements a condition of planning approval.’ That is probably unnecessary if they are legal requirements, but would you build, or invest in, a new runway if you weren’t sure it could be used?

On top of recent developments on air quality though, the evidence relied on by the Airports Commission on surface access states as follows (3.4.2):

‘with the baseline network in place by 2030, 43% of passengers are predicted to travel to and from Heathrow by rail, a value which is significantly higher than the 28% rail share observed in 2012. The proportion of passengers arriving at Heathrow by car is expected to reduce from 59% in 2012 to 46% in 2030. This would mean that there will be over 56 million passengers using public transport compared to around 29 million today, and 6 million more passengers travelling to and from the airport by car.’

Call me unsophisticated, but I just can’t see how adding 6 million car passengers a year onto the access routes to Heathrow won’t slow down achievement of air quality targets. But maybe I am being too simplistic and I am happy to be persuaded otherwise.

Anyway, two very significant High Court judgments affecting infrastructure projects – and much more – in one week is certainly something to write home – or a blog – about.

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