The environmental case for Heathrow expansion remains as weak as ever, regardless of Yeo's attack on the Prime Minister
There are many reasons why Tim Yeo is wrong about the need for a third runway at Heathrow. But let us focus on just one of them, the assertion that aviation's inclusion in the EU emissions trading scheme (ETS) means the environmental objections to expansion at Heathrow are "disappearing".
This is manifestly untrue, as evidenced by the angry response to his plea for a third runway from green groups, but even if the European ETS was working perfectly (which it isn't) it would do little to strengthen the case for more airport capacity.
Yeo's argument that the inclusion of aviation in the European emissions trading scheme means "we could cover the whole of Surrey with runways and not increase emissions by a single kilogram", makes a certain kind of sense: the emissions cap imposed by Brussels should ensure emissions do not rise regardless of new infrastructure investment. But the argument is fatally flawed on two fronts (and that is before you even look at issues such as air and noise pollution).
In practice, there are too many weaknesses in the ETS that still need to be addressed to suggest aviation's inclusion in the scheme magically resolves the sector's environmental problems.
As EU officials have repeatedly admitted, the carbon price is currently too low, there are too many credits in the market, and the emissions caps are too high. In addition, it is too easy to import questionable carbon credits from outside the bloc to help meet those emissions limits.
The EU ETS can work effectively and aviation's inclusion is a step in the right direction, but until the current deadlock over the future of the scheme is resolved and the various flaws in the market are corrected it is impossible to say with any real confidence that airports can expand across whole counties without posing any threat to UK and European emissions targets.
However, the real flaw in Yeo's argument would apply even if the ETS was working perfectly.
Aviation's inclusion in the ETS is effectively a means of putting a carbon price on flying. As such, if the number of flights increases airlines have to buy in more emission allowances to cover their carbon footprint, driving up costs and therefore ticket prices.
The only way this cost would be manageable is if other sectors of the economy deliver such deep and rapid reductions in emissions that they are left with a glut of allowances that they would then sell to airlines at a knock-down price. But you'd be hard pressed to find a single credible expert who believes emission reductions of this pace and scale are on the horizon.
The expansion of Heathrow would allow more flights, which would result in increased carbon costs and higher ticket prices, which in turn should result in reduced demand for flights. If the ETS works as Yeo says he wants it to work then it is a mechanism for curbing demand for aviation that should inherently preclude the need for more aviation capacity.
The price of carbon determined by the ETS is expected to rise over the coming decades as emissions caps are tightened and carbon targets increased. This is why there is an increasingly compelling financial argument against the construction of new carbon-intensive infrastructure, regardless of whether that infrastructure comes in the form of coal-fired power stations or new runways. It is an argument Yeo used to adhere to.
As I have argued many times before, there is only one environmentally credible argument for airport expansion, and that is the prospect of low or even zero carbon flight. Sadly, despite billions of dollars of investment and plenty of interesting research avenues, the prospect of genuinely green aviation is decades away at best, meaning there is currently no case for airport expansion in industrialised countries that is consistent with their stated goals to reduce emissions.
Sensible businesses are already adapting to this new reality and developing green travel policies that reduce their reliance on business flights through a combination of videoconferencing, rail travel, and new working practices.
Yeo's intervention is easy to understand given recent attacks from right-wing newspapers who have finally noticed his properly declared involvement with a number of green businesses could be seen as a conflict of interest with his chairing of the Energy and Climate Change Select Committee (for what it's worth, it is clear the problem here lies more with our parliamentary system than it does with Yeo – if we kicked out every MP and peer with business interests that could be seen as conflicting with their parliamentary work both chambers would be virtually empty).
But Yeo must now ask himself whether he is man or mouse. His place in history is assured as the Tory MP who has arguably done more than any other to promote the concept of a greener economy, an achievement that eluded hundreds of MPs before him. But does he want to be another opportunistic and inconsistent backbencher, presiding over a dignified slide towards insignificance? Or is there somewhere inside his heart – an organ that still remains impenetrable to most Britons – a trace of the environment minister he once was, determined to protect the UK's green credibility?
All the green business news from around the world this week
'Without companies aligning their business models and operations with the SDGs - they simply won't be achieved' experts warn
Climate Bonds Initiative forecasts major global growth ahead that could see first $1tr issuance hit in early 2020s
The fund's new targets are intended to align with targets set by the UK Green Building Council