Schiphol: what's the optimal level of pollution? November 1999

The Netherlands is the most environmentally sensitive country in Europe.

For example, windsurfers are currently being accused of causing "visual pollution" along the nation’s coastline.

Evidently then, Amsterdam’s Schiphol Airport has a very high profile with environmentalists and needs an effective green strategy.

In 1995 the Dutch Government produced an integrated plan which included over a hundred different measures related to the future development of the airport. Whilst approval was given for the construction of a fifth runway, which was aimed at diverting traffic to a less noise sensitive approach to the airport rather than to providing more runway capacity, the airport was also set a series of environmental limits.

These were primarily:

• A noise contour that was not to exceed 15,000 houses until 2003, and to be reduced to 10,000 houses beyond 2003;
• Total passengers handled not to exceed 44m in any one year;
• Total cargo tonnes handled not to exceed 3.3m in any one year.

The growth in traffic at Schiphol (passenger numbers increased by 9.7% in 1996, 13.2% in 1997, and 9.4% in 1998) has meant that the airport exceeded its noise contour limitations in both 1997 and 1998, resulting in the airport being taken to court. The government allowed an exemption to be granted to Schiphol for the breaches of the noise limitations but in turn put in place a limitation in the future growth of slot movements at the airport.

The maximum number of annual slot movements has been set at 380,000 movements for 1998 and annual increases to be limited to 20,000 movements thereafter. In 1999, the airport will keep below its limit of 400,000 movements and meet its noise limitations. The question for Schiphol is, however, how to meet future demand whilst meeting the both the limitations on movements and the need to meet the more stringent noise target that will come into force at the end of 2003.

Modelling policies

A study* to monitor environmental capacity issues at the airport has come up with some interesting initial findings on the measures that could provide the optimal balance between economic costs and environmental benefits. Under the high growth scenario, Schiphol on an unconstrained basis would be expected to handle some 64m passengers p.a. by 2010, up from its 1998 level of 34m passengers.

The study then modelled several policy variants that would keep Schiphol within its environmental constraints, but at the same time allowing growth at the airport at a minimum cost to the airport’s users (the airlines).

The outcome of modelling two of these variants — involving financial measures and imposing noise and capacity limitations — are shown below. (Other options considered included changes to flight scheduling and technical operations.)

The modelled options were assessed by their impact on:

• Passenger traffic (split by terminating and transfer passengers, business and leisure, and by short and long–haul);
• Noise (split by cargo and passenger, type of aircraft, and by usage of the airport throughout the day); and
• Cost to the airlines.

Option 1:

A Fl12.50 (US$26) levy per departing seat or Fl125 per tonne of cargo

The model showed that such a levy would increase the cost of operating from the airport to the airlines by about 3%. By far the largest impact would be on the highly sensitive cargo operators, which would result in the number of cargo movements falling by some 70%. Transfer and leisure passenger traffic, which is also price sensitive, would also fall, producing a reduction in passenger traffic of about 6%. The fact that some of the cargo operations are using noisy aircraft and that a large proportion of the movements occur between 2300–0600 hours (which carries a noise weighting 10 times higher than daytime movements) meant that this option produced a 20% noise reduction for a 3% increase in costs.

Option 2:

Direct noise levy on aircraft types

Schiphol formed its own classification of aircraft types that included sub–dividing Stage 3 compliant aircraft into noisy, medium noisy and quiet types. The quiet types would be able to use the airport at no additional expense, but levies would be introduced for more noisy types. This option once again produced a forecast that showed cargo movements most badly impacted, falling by just over 50%, but proved to be more efficient than Option 1 producing an overall reduction in noise at the airport of 30% for just a 3.5% increase in costs.

Option 3:

Noise levy by aircraft type and by time of day

Using the same noise classifications in Option 2, the levy applied to the airlines was also adjusted for the time of day. So usage between 0800–1800 hours carried the lowest levy, the levy increased 3.75 times for usage between 1800–2300 hours, by 5.6 times between 0600–0800, and by 10 times between 2300–0600 hours. This proved to be more efficient than Option 2, producing a 33% noise reduction for just a 3.5% increase in costs. Unfortunately this measure exaggerated further the impact on the cargo operators producing a fall in cargo traffic of 70%.

Option 4:

Passenger quota limitation of 44m

A simple levy aimed at reducing passenger usage at the airport by imposing cost increases across the board produced a very inefficient result. A 30% noise reduction was only achieved by producing a 20% cost increase.

Option 5:

Slot trading and a 600,000 annual movement quota

As well as not being permitted under EU law, slot trading produced a relatively inefficient result. In order to achieve a 30% noise reduction costs would have to increase by some 7%.

Airline implications

Restrictive quotas on passengers and/or movements are an inefficient method of solving the noise problems at Schiphol. More efficient are options that incentivise airlines to use both quieter aircraft and to fly during social hours. Schiphol is currently modelling pollution quotas, which are expected to be even more efficient than Option 3, the best of those shown above.

Whatever policy is chosen it must be cost–related, transparent and not biased to any one airline. A creative mix of policy measures such as the options outlined above may be able to keep the environmentalists happy as well as giving the airport growth possibilities beyond 600,000 movements by 2010.

Perhaps the most difficult task will be keeping KLM happy. The airline is heavily biased by European standards to both transfer traffic and to carrying cargo, both of which are adversely impacted by the main policy options considered. Ultimately, KLM may have to re–equip its entire fleet with ultra–quiet types, while other European carriers would only need to have a couple of ultra–quiet aircraft in its fleet to be still able to serve Schiphol.