The Transport Secretary was interviewed in the Evening Standard on Monday.
In a relatively free-ranging piece she attacked the "pub style" debate over aviation policy being held by airline and airport bosses and called for a Victorian attitude to long-term planning for London's airport capacity:
“The Victorians-finished a railway in 1899 that we can still use today because they built in so much extra capacity.
“They constructed sewers under London that withstood a doubling of the size of the city, so that we are only now having to build the supersewer. By contrast in the aviation sector we have seen piecemeal decisions taken — and often not taken.
“I think the mistakes of the past have been characterised by piecemeal, ad hoc and often rushed decisions which ultimately have got us into a position today where there are really difficult decisions facing us.”
In its editorial the Standard welcomes the debate and notes that any solution will involve both short-term fixes and longer-term solutions.
Of course, just because the Transport Secretary has decried "pub-style" debates doesn't mean that others won't engage in them. Stewart Wingate, Gatwick's Chief Executive, has entered the debate, calling on Heathrow to "stop moaning" about capacity problems and for the Government to shift its focus to his airport. Indeed, he makes the case that many of the concerns caused by Heathrow's expansion would be less problematic if applied at Gatwick:
“There’s a noise contour which says that in and around Heathrow there’s about a quarter of a million people that live very close to that noise contour.
“But the equivalent numbers for Stansted or Gatwick are broadly comparable at about 2,000-3,000 living in the same noise-impacted area.”
Others, meanwhile, continue to push the case for Heathrow.
Elsewhere, the London Assembly has passed a resolution calling on the Mayor to drop his plans for a hub airport in the Thames estuary.
Ms Greening's comments about her role in defining the future of London's aviation sector ("My job is to say ‘what do we need for the next 20, 30, 40 or 50 years?’ What if we realise we need a fourth runway? Where would that go at Heathrow?”) suggest that she plans on looking at a bigger solution than an extra runway here or there.
So what does that leave?
She was very careful not to be drawn but two obvious options for Ms Greening are to better balance capacity between London's existing airports (perhaps including direct [high speed?] rail links between airports), or embracing the idea of a new hub airport, modelled on Hong Kong. Either would require huge investment and cause disruption to many, many people.
The politically expedient option is a fudge - perhaps increased flights at Heathrow and an extra runway at Stansted, but Ms Greening appears to be thinking big. Whether her actions meet her words is another matter.
The Standard is hosting a debate about London's airport future tomorrow night. LondonUnlocked will be there and we'll post coverage of the event on Thursday.