20/12/2013 03:51 GMT | Updated 18/02/2014 05:59 GMT

Why the Green Light for a New Runway Could Still Turn Red

Before the 2010 election, David Cameron famously promised "no ifs, no buts, no third runway" at Heathrow, Nick Clegg warned a third runway would be a "disaster", and Ed Miliband threatened to resign from Cabinet over the issue.

This week, we've seen the major parties edge towards a potential about-face on the back of the conclusions of the Airports Commission's interim report that a new runway is required by 2030. The Commission has shortlisted options at Heathrow and Gatwick (and potentially in the Thames Estuary) for where the new runway should go and intends to spend 2014 analysing them.

However, the reason that politicians came out against a new runway back in 2010, reversing a decision in favour of new runways at Heathrow and Stansted, wasn't for a lack of perceived need but down to the power of local opposition. This opposition centres on the disturbance caused by aviation noise to the lives of over a million people in communities close to airports (around 750,000 of whom are near Heathrow). Air pollution, and its associated health impacts, has also stirred up opposition and was partly why a third runway at Heathrow wasn't built while it enjoyed political support from the last government. London is already being threatened by the EU over breaches of legal air quality limits and with air pollution at Heathrow already bordering on these thresholds (best visualised in annual maps of air quality in London), the issue is likely to kick up a storm again this time around. Communities around Gatwick face similar challenges to those around Heathrow.

The Airports Commission has paid lip service to the importance of community opposition in previous failed expansion attempts by saying at the beginning of the report that "decisions on airport capacity (should) balance local considerations with the national interest". Yet the Commission hasn't so far applied this logic to its own work, addressing only the issue of demand and capacity in the report and leaving 2014 for a detailed look at the local situation.

Separating the national picture from local concerns may make sense as an approach for the Airports Commission as local impacts are obviously dependent on where they are. But in separating the two, and making the conclusion that additional capacity is required and can be delivered from one of the shortlisted options, local concerns appear to be an afterthought. Having made his conclusion, would Sir Howard Davies, Chairman of the Commission, be welcome at any airport if he should subsequently decide that the local impacts for each option are too great for a runway to be built? This would definitely be a possibility if the Commission was to apply its own logic as the problems, which prompted such strong words from the coalition back in 2010, have not gone away.

The communities around the shortlisted options, at Heathrow, Gatwick and the Thames Estuary, will have to wait until 2015 to find out which is the favoured option. The next year of uncertainty will coincide with the beginning of the campaign trail in marginal seats in West London and the South East. The interim report provided no reassurances to the affected communities, only the vague promise of an independent noise body and a prediction that the number of people living within a certain noise contour (which is considered as a poor indicator of noise annoyance) will decrease to around 100,000 by 2050.

Without any reassurances from the independent Commission, communities will look to politicians to provide them. The Airports Commission has failed for now to achieve its purpose to take the politics out of the airports debate. Has this week's announcement really given the green light to a new runway or just reopened the political debate?