This is the material from the flyagra website, some of which is now slightly out of date, but nevertheless provides coherent reasons that stand up to scrutiny:
The case against the airport company’s expansion proposals
The Runway Extension is merely the most high-profile development (after the Second Runway) currently being proposed. It is one part of a much larger programme of expansion. Our campaign is about more than just fighting individual proposals like the runway extension or the third terminal. We also want to challenge the underlying ‘predict and provide’ rationale of airport expansion.
Nevertheless, there are several reasons to oppose the Runway Extension in particular.
1. The Runway Extension is not a substitute for the Second Runway. In fact, it makes the Second Runway more likely to go ahead.
The Runway Extension is merely ‘phase 1’ of a much larger programme of expansion culminating in the Second Runway. Without the Runway Extension the Second Runway cannot go ahead.
The master plan is subject to regular review.
The master plan states that ‘as the forecasts are reviewed. over future periods, runway capacity and the need for a second runway could be reconsidered’, paragraph 7.2.24.
2. The Runway Extension will mean aircraft noise will get worse and affect more people across a wider area compared to today.
Operating a longer runway will mean:
– Closer and lower flights over residential areas; 
– More people over a wider area exposed to aircraft noise pollution compared to either today or 2030 without the extension;
– Scrapping operational measures designed to mitigate noise. For example, with a longer runway, the airport will no longer be able to operate the ‘Hampton Turn’, the southerly departure route from the current runway which takes planes away from the village of Hampton-in-Arden; 
However, noise pollution from the airport is set to grow regardless of whether the runway extension goes ahead or not.
The runway extension will improve runway capability, by increasing the range of destinations and routes which can be served, but it does not increase runway capacity, i.e. the number of runway movements available at peak times. More aircraft cannot be accommodated without extra runway capacity.
The capacity of the runway is measured in aircraft movements per hour. The peak hourly capacity of the Main Runway is currently 40 movements per hour. Higher rates could be achieved with further improvements to the airfield layout, to include additional taxiway links, fast turn-off taxiways and rapid exit taxiways. These improvements could increase the capacity of the main runway to 48 movements per hour.
3. The Runway Extension is being rushed through in order to prepare for the 2012 Olympics.
In March 2006, BIA’s seven local authority shareholders called for the Runway Extension to be brought forward from 2015 to 2012 in time for the London Olympics , a demand echoed by the Institute of Directors that same month  and later by the Birmingham Chamber of Commerce and Industry. 
This is dangerously short-sighted. The London Olympics and Paralympics will last only four weeks in 2012.
Other transport issues should be given priority.
Tackling road congestion. n September 2006, a feasibility study on how to tackle congestion across the region was published. The independent report, commissioned by the seven West Midlands metropolitan authorities and the Passenger Transport Authority-Centro, also states: Congestion will increase by 22 per cent by 2021, adding an extra 469,000 car journeys and 330,000 delay hours on the region’s roads;
This would cost the West Midlands an extra £205 million a year, and could result in 40,000 predicted jobs over the next 15 years not materialising, which would equate to seven Longbridge closures.
4. The Runway Extension will create pressure for further development.
Widening of the M42 motorway
BIA is unwilling to fund the extra surface transport infrastructure necessary to support the airport’s expansion.
5. The economic benefits of the Runway Extension are questionable and the costs have been ignored.
In 2006, BIA handled 9,153,047 a fall of 2.5 per cent on 2005.
The airport supports 10,500 full-time equivalent jobs in 2006. This is forecast to grow to over 19,000 by 2030.
The boom in cheap flights from West Midlands airports is costing the regional economy four times as much as it gains. Using data gathered from the Office for National Statistics, FoE researchers claimed domestic travellers using the region’s airports were spending £1.7 billion more on their trips abroad than overseas visitors spend in the UK.
All regions of the UK except London received far less in revenue from foreign residents than the amounts spent abroad by Britons. The increase in cheap flight sales was mainly due to better off people making more leisure trips on short breaks or visiting their second homes abroad.
The growth is possible only because the aviation industry doesn’t pay for its huge environmental impacts and is exempt from paying most taxes like fuel tax.
Local businesses are missing out on millions of pounds every year and airport expansion will make this worse.
Most flights are not undertaken for business.
4 per cent of the population flew more than 5 times a year and accounted for a third of all leisure flights.
6. The taxpayer will partly foot the bill for the Runway Extension, yet another instance of public money subsiding aviation.
The extension is estimated to cost around £120 million once infrastructure costs are taken into account. The regional development agency Advantage West Midlands announced in February 2007 that it was prepared to commit a £25 million grant (of public money) to the project, conditional upon the airport company promising to address public transport, environmental and sustainability issues.  The remainder of the money is expected to come from the airport’s owners, including the seven West Midlands local authorities which own a 49 per cent interest in the airport.
7. Proposals to expand airport infrastructure risk making it even more difficult to reduce aviation’s contribution to climate change.
Allowing unrestricted aviation expansion is completely at odds with tackling climate change: it will mean huge increases in emissions at a time when the focus should be on how to make big cuts. The voluntary solutions proposed by the aviation industry are totally inadequate and must be complemented with measures to manage demand so that aviation emissions decline. It will be much harder to reverse growth in the future when the aviation industry has invested in more runways and the public is even more ‘air dependent’.
More flights means more emissions.
Civil aviation is the fastest growing source of human greenhouse gas emissions and yet the industry is not covered by the international climate change frameworks. This effectively exempts aviation from either national or international agreements and actions to limit emissions from flights. International aviation and shipping emissions are not included in the Kyoto Protocol because responsibility for them has yet to be agreed at an international level.
Unlike many sectors of industry, the aviation industry is expected to grow its carbon dioxide emissions.
There is little prospect of a significant technological breakthrough that will reduce aircraft emissions. Gradual improvements might manage 1.2 per cent per year reduction in emissions. But this is inadequate to counter the current growth in passengers of 6.4 per cent per year.
Aviation emissions are estimated to have between two and four times the climate change impact of carbon emissions alone due to complex chemical reactions at altitude.
The UK government is seeking to have aviation included within the scope of the European Union’s Emissions Trading Scheme, a small step in the right direction. But the scheme will not start until 2010 at the earliest and will only have a small impact on cutting emissions. There is evidence that the existing Scheme is failing to cut emissions from industries already participating and some EU states plan to increase their overall emissions in the second phase of the EU ETS from 2008 .
BIA lies outside the boundaries of Birmingham and so not covered by the Birmingham Strategic Partnership’s Climate Change Strategy and Action Plan. The draft Strategy proposed setting up a voluntary ‘offset’ scheme for passengers using BIA, the revenue from which would support energy efficiency works for the benefit of low-income households in the city. The airport company has agreed in principle to this proposal.
Friends of the Earth successfully campaigned for aviation emissions to be covered by the Climate Change Bill
8. The environmental benefits of the Runway Extension are questionable.
Extending the runway would allow the airport to increase the capability and range of services. The current runway is unable to accommodate direct long-haul flights to destinations such as the West Coast USA, the Far East and the Indian sub-continent.
BIA argues that extending the runway will enable the airport to satisfy a greater share of the regional demand for air travel, thereby reducing long-distance car journeys to other UK airports. More passengers to fly from their local airport rather than driving to Manchester, Heathrow or Gatwick.
The lion’s share of BIA’s future growth will come from a rise in demand in the West Midlands for short-haul flights, not from a greater retention of travellers currently going elsewhere to start direct long-haul air journeys. Overall, the airport’s contribution to climate change, directly from aircraft emissions and indirectly from associated road journeys, will continue to grow.
In 2000 BIA served 40 per cent (5.84 million) of its ‘one-hour market potential’, in other words the 14.6 million people who live within an hour’s drive time from the airport. By 2006, the population within this one-hour radius had grown by 41 per cent to 20.6 million people. The airport’s market share however had fallen to 36 per cent, or 7.42 million people. 
These facts in themselves show that the logic of claw-back is flawed. BIA’s passenger numbers grew from 2000 to 2006; they lost business to other rapidly growing airports all of which are seeking to claw back business from BIA.
Nottingham East Midlands Airport (NEMA) increased its share of the one-hour market share from 8 per cent to 14 per cent in those five years, and Coventry (Baginton) Airport from 0 to 2 per cent. Neither of these airports offer direct long-haul flights to the destinations BIA hopes to serve with a longer runway.
And yet Manchester Airport (which does) remained static at 11 per cent of the one-hour market.
London Gatwick Airport’s share fell from 10 per cent to 6 per cent, London Heathrow’s from 19 to 13 per cent. London Stansted’s share only increased by 2 per cent over the period.
Most of the BIA’s future growth will arise from an increase in demand from the airport’s regional catchment area, not from a greater retention of traffic currently travelling outside the region to start air journeys
Other airports are using the same rationale to justify their own expansion plans, and despite all this expansion at regional airports, all three south-east airports are themselves forecast to grow and expand heavily over the period to 2030. The growth in greenhouse-gas emissions and surface congestion from the overall growth in air travel and associated road journeys will far outstrip the savings made by regional airports serving a slightly increased proportion of the regional demand locally.
As long as people are free to choose which airport to fly from, and barring a Heathrow-sized airport in every region serving every destination the world 24 hours a day and seven days week, there will always be a certain degree of leakage from one region to another.
New road building schemes were frequently justified in similar terms, with developers and the government arguing that new roads would remove traffic from towns and thus reduce local pollution and congestion. But, as the Standing Advisory Committee on Trunk Road Assessment (SACTRA) has shown, this resulted in a vicious circle of increasing traffic prompting more road building, which in turn generated increased traffic and congestion.
With each airport vying to claw back passengers from its rivals the result is an ‘arms race’ of the skies.
The importance of Birmingham International Airport to the region is not disputed. This does not however give it carte blanche to develop in an unsustainable way.
 Civil Aviation Authority Surveys – Londonb, MAN, BHX & EMA 2006 & Regional Airports (Apr 03 to Mar 04 applied to 2006 Volumes), CAA Statistics.
 BIA Ltd. press release, ‘BIA announces Interim Statement on the future of the Airport’, 26th September 2007. Ref 07-058.
 BIA acknowledged this concern, raised by Catherine-de-Barnes Residents’ Association at the Airport Consultative Committee meeting of 23rd May 2007. See http://www.ukaccs.info/bham/bhxaccminutes230507.pdf.
 BIA Ltd. and a a Health Impact Assessment Steering Group have commissioned IMPACT+, the International Health Impact Assessment Consortium, based in Public Health at the University of Liverpool, to undertake a health impact assessment of the proposed runway extension. Workshops were held with local community organisations on 10th and 11th September 2007 in Marston Green, Solihull and Sheldon. A presentation provided by the airport company to IMPACT includes a new map of the current and forecast 57 dBLaeq ‘noise contours’, showing how the noise footprint will expand as the airport grows. The presentation also stated that the ‘Hampton Turn’ would not be possible with a longer runway.
 ‘AWM right to back airport plan’, Birmingham Post, 1st February 2007.
 ‘£25m grant towards new runway’, Birmingham Post, 1st February 2007.
 Paul Dale, ‘Bring runway extension plan forward’, Birmingham Post, 6th March 2006.
 Paul Dale, ‘Business urged to back ‘vital’ expansion of BIA runway’, Birmingham Post, 9th March 2006.
 Jonathan Walker, ‘Call to expand airport before Olympics’, Birmingham Post, 15th December 2006.
 Emma Brady, ‘Road charging: the final choice’, Birmingham Post, 21st September 2006.
 availability of cheap flights is leading to societal changes that will encourage more flying in future, see pages 36-38 ‘Predict and Decide’, Oxford University.