In a High Court judgement last week, Mr Justice Garnham ruled that the government’s air quality plan (AQP) failed to comply with Article 23 of the EU Air Quality Directive, which sets out an overarching legal framework. The plan, drawn up by the Department for Environment, Food and Rural Affairs (DEFRA), outlines a strategy to improve air quality and measures to reduce nitrogen dioxide (NO2) emissions in 38 areas where they currently exceed EU emissions limits.
But, after a legal challenge brought by environmental pressure group Client Earth, the judge ruled that the AQP was deficient due to its reliance on over-optimistic modelling of reductions in NO2 emissions from diesel vehicles. Garnham also ruled that the plan’s target date of 2020 - or 2025 in London - for areas with emissions that exceed the permitted levels was too distant, saying that the government must aim for compliance with the directive "by the soonest date possible".
The plan was published in 2015 after its previous iteration was been found unlawful in another legal action brought by the same pressure group. Ruling that the latest AQP should be quashed, the judge ordered the government and Client Earth to negotiate a settlement. Discussions on this were ongoing as Planning went to press. A revised plan is likely to have to bring forward compliance periods and experts said there could be implications for infrastructure schemes. Such projects are likely to face stricter scrutiny of air quality impacts and greater vulnerability to legal challenge, they said.
"If you are bringing forward a scheme which is likely to have significant adverse impacts on air quality, you will need to think through the potential ramifications", said Simon Ricketts, a partner at law firm King & Wood Mallesons. "There could well be a challenge based on the fact that the scheme could exacerbate the extent to which we are in non-compliance with the directive."
Duncan Field, partner at law firm Norton Rose Fulbright, agreed. "It seems likely that there will be increased scrutiny of air quality indicators," he said. "The shortened timescales mean that proposals with less significant impacts could become more important in achieving the required emissions reductions within that timescale," he said.
Client Earth suggested that the decision could have impacts for airport expansion if it were found to exacerbate poor air quality, and some experts concurred with this view. Angus Walker, a partner at law firm Bircham Dyson Bell, pointed out that when the government took its decision to endorse Heathrow, its report on the air quality impacts of the expansion used the same modelling as the AQP. "If that is based on a significant underestimate of emissions from vehicles, it is difficult to see how it remains valid," he said. "Although the Heathrow plans will result in modal shift from cars to public transport, there will still be 6 million more cars per year travelling to Heathrow. How can that not have an impact on air quality?"
But Field said that the judgement could bring benefits for the Heathrow project. "If the government is proceeding with a plan that shortens the timescale for compliance and contains more effective measures to achieve that, then Heathrow may be able to benefit form a better air quality baseline by the time it opens in 2026," he said.
Kevin Gibbs, a partner at law firm Bond Dickinson, agreed, suggesting that the vehicle movements at Heathrow may not have to be reduced by as much as previously planned if other measures have already delivered air quality improvements in the meantime. He noted that these measures would include "a stricter framework for everything - particularly diesel - and more green technology".
But Walker questioned whether the government would be able to drive forward such technological improvements in the car industry. Meanwhile, Ricketts said that, even if the baseline position for Heathrow expansion improves, "the airport proposal is likely to significantly worsen air quality".