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What answers has the Government found to the environmental hurdles facing a third runway?

25th October, 2016

With the Government now having officially announced its support for a new runway at Heathrow, despite having slashed the Airports Commission’s claim of a £147 billion benefit to the UK by almost 60% (referring instead to a benefit over sixty years of ‘up to £61 billion’), we take a first look at what they have to offer in terms of answers to some key environmental challenges.

Climate Change

As AEF has consistently pointed out, and as the Committee on Climate Change reminded Government today, there is no plan for delivering the aviation emissions limit required to deliver the Climate Change Act either with or without a new runway.

The last time we had a government supporting runway expansion, it specified that this would be conditional on the sector’s CO2 emissions being on course not to exceed 37.5 Mt by 2050, in line with the CCC’s advice. Today’s announcement included no such commitment, instead making vague references to the global carbon offsetting scheme for aviation agreed this month, and to potential efficiencies arising from better air traffic management – both measures that are (effectively) already taken into account in the CCC’s modelling, and that won’t bring us anywhere near to achieving the minimum level of ambition required under UK law.

So what does the Government have to say about how the CCC’s recommendation will be met? The answer is deeply buried in a technical paper released alongside the announcement which states that the Airports Commission’s carbon-capped scenario “is helpful for understanding the varying effects of constraining aviation CO2 emissions on aviation demand and the impact on the case for airport expansion but was described by the AC as ‘unrealistic in future policy terms'”. In other words it can’t be done.

Air pollution

With the Heathrow area consistently breaching legal limits for nitrogen dioxide and the Airports Commission anticipating that expansion at the airport would have an adverse or significantly adverse impact on air quality, this represents a clear legal obstacle that the Government must be ready to take on. Today’s announcement indicates that a ‘re-analysis’ by Government of air pollution levels subsequent to the Airports Commission’s report has shown that “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.”

The problem is that Government appears to have little idea what those mitigation measures will be, and the deliverability of the plan has already, therefore, been questioned through the courts. ClientEarth, which brought the action, said today in a statement “Those plans were so poor that last week we took them [the Government] back to the High Court to force action on air pollution. The government needs to produce an in-depth and credible plan to drastically cut air pollution to meet its legal obligations rather than digging an even deeper hole for itself.”


With Heathrow’s noise already affecting more people than its five main European rivals combined, the likely noise impact of expansion has always been at the heart of much of the political opposition to a new runway. Today’s announcement includes the statement that “The government will propose that a six-and-a-half hour ban on scheduled night flights will be introduced” but gives no indication of preference for whether this will run from 11:30pm to 6:00am as recommended by the Airports Commission or from 11:00pm to 5:30am as proposed by the airport, with numerous flights potentially scheduled from 5:30 in the morning. Meanwhile the noise impact, including for the hundreds of thousands predicted to be newly affected, will depend heavily on the precise location of flight paths – an issue potentially as contentious as the expansion itself.


The Conservatives’ mayoral candidate Zac Goldsmith has already announced his decision to resign in response to the Government announcement, and the Government is now relying on the support of both Parliament and the Lords to get approval for an Airports National Policy Statement supporting expansion (not to be published for consultation until next year). This is – of course – not the end of the debate but in many ways just the beginning.