5.3.3 How will the environmental impact be mitigated or paid for?
As major expansion was now seen as inevitable by the government decision makers, the issue of aviation’s environmental impacts had to be dealt with. Any study and/or valuation of environmental impacts by the aviation industry had to take into account the following key issues:
- Noise – this is the single most important issue at the local level. Although significant improvements in aircraft engine design have resulted in drastic noise reductions, the sheer quantity of take-offs and landings is still causing levels of distress for people living near airports. Prolonged exposure to high levels of noise has been shown to cause loss of concentration during the daytime and sleep deprivation at night, sometimes leading to heightened stress levels and a reduction in immunological defences.
- Emissions – these result not only from the aircraft themselves, but from ground support vehicles, refuelling and power generation equipment, and the extensive transportation infrastructure required to bring people and goods to and from airports. These create air quality problems locally and contribute to climate change globally. To the latter, one can add the potentially significant effects of condensation trails (contrails for short). These are the plumes of cloudlike condensation left behind in the atmosphere by passing aircraft. These plumes contribute to the reflection of heat back to earth and could contribute significantly to global warming. The particular chemicals involved include nitrous oxides, volatile organic compounds (VOCs), sulphur dioxide, ozone, small particles which contribute to health problems in the immediate surroundings of the airports and CO2 as a major contributor to greenhouse gases in the atmosphere.
- Water quality – on-site aviation industrial activities such as aircraft de-icing, maintenance and refuelling can cause the contamination of surface and groundwater. This could potentially affect the health of humans and other organisms directly by polluting drinking water supplies, or indirectly by incorporation into the food chain.
- Waste – in-flight catering and toilets, along with extensive terminal facilities, generate significant amounts of liquid and solid wastes. These require large-scale treatment facilities which, if unavailable or malfunctioning, could threaten human health and the surrounding environment.
- Land-take – this is probably the least publicised environmental impact, but the building of new runways, terminals and access infrastructure, and indirect development as a result of the economic stimulation, may result in additional pressure on green spaces which are already scarce, especially around already heavily urbanised areas such as London.
Box 7 Greenhouse gases and climate change
Greenhouse gases, including water vapour (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), have the effect of warming the global climate. Without them, the earth’s temperature would be considerably colder than it is now. The gases allow radiation from the sun to pass through, but they reflect some of the heat that radiates back from the earth’s surface. An increase in atmospheric concentration of these gases increases the reflective ability of the atmosphere and thus results in higher global temperatures. Different gases have different reflective properties. For example, a kilogram of methane is 23 times more powerful at reflecting heat back to earth than a kilogram of carbon dioxide, while nitrous oxide is 296 times more powerful. So when estimating the impacts of these emissions, it is not only the quantities released into the atmosphere that have to be taken into account, but also their reflective power.
The major contribution of air travel to greenhouse gas emissions is CO2. Air travel currently accounts for 3.5% of CO2 emissions, although the ‘Aviation and the Global Atmosphere’ study carried out by the Intergovernmental Panel on Climate Change in 1999 shows that the effect could be three times more potent as a result of the emission directly into the upper atmosphere.
So how should the government ensure that aviation meets the external environmental costs for which it is responsible? Should greater emphasis be placed on regulation (at global, national or local level), economic instruments or voluntary agreements? The ‘Valuing the External Costs of Aviation’ document set out the government’s fundamental approach to tackling environmental issues:
Under the polluter pays principle, external costs should be reflected in costs incurred by the aviation industry, so that (in an ideal world) it fully meets its external costs.
The ‘polluter pays principle’ basically implies that whoever causes pollution is responsible for the costs of repairing any damage. The ‘external costs of aviation’ are therefore an attempt to quantify in monetary terms the costs of repairing or compensating for the environmental impacts listed above.
The following is an example of how the government proposed to meet the ‘external environmental costs’:
Monetary values for the effects of noise were estimated by assessing the impact of increased air traffic noise on house prices in the region of the airport option. The tentative finding of past research, that a 1 decibel change in noise level results in an approximate 0.5 to 1 per cent change in house prices, was used to estimate the order of magnitude of the noise value of different options. Values at Heathrow ranged between 36 and 40 pence per passenger; at all other airports in the South East, values never exceeded 5 pence per passenger.
(A decibel is a measure of the loudness of sound. A value of 0 dB is at the threshold of human hearing while values above 85 dB are considered harmful to human hearing. Many aeroplanes are capable of producing 100 dB at a 170m distance.)
The 5 pence levy per passenger for all the airports in the South East of England (except for Heathrow Airport), was seen to represent adequate compensation for the disruption caused to residents surrounding the airports and would be included in the ticket price for those journeys leaving from the South East of England. A higher charge would be placed on tickets leaving from Heathrow.
The other significant environmental impact that was converted into monetary costs by the report was climate change as a result of CO2 emissions. The valuation of climate change impacts as a result of CO2 and other greenhouse gas emissions is an extremely problematic and controversial area, with estimated costs ranging from £3 to £120 per tonne of carbon, and £1500 to £2400 per tonne of nitrous oxide. These upper and lower limits are constantly changing as scientists argue on the effects of global warming – for example the influence on the frequency of hurricanes in the USA, droughts in Africa and floods in Bangladesh. The values in Table 4 show the estimated monetary costs (in pounds sterling) for different aircraft types, i.e. the values represent the estimated costs of environmental damage caused by each journey for each aircraft type (short-haul journeys represent domestic and European travel while long-haul journeys represent extra-European travel such as to the USA or Asia). You can see that the values differ greatly between high and low estimates, yet the DfT required a single value for short-haul and long-haul flights to be passed on to the ticket price, so a weighted average was taken of the ‘medium’ figure reflecting the proportion of different aircraft types using UK airports and the proportion of short-haul and long-haul operations.
Table 4 Damage costs per journey in pounds sterling as a result of climate change impacts from aviation emission according to aircraft type and journey distance
|Short-haul operations||Long-haul operations|
|Aircraft type||Low cost (£)||Medium cost (£)||High cost (£)||Aircraft type||Low cost (£)||Medium cost (£)||High cost (£)|
|Boeing 737-400||106||211||422||Airbus 340||1768||3536||7072|
|Airbus 320||127||254||508||Boeing 747-400||2486||4972||9944|
|McDonnell-Douglas 82||150||300||600||Boeing 767-300||1223||2442||4890|
|Boeing 757||184||368||736||Boeing 777||1886||3771||7542|
Other impacts, such as those on water quality, waste and land-take, were seen to be either insignificant and/or too complex to quantify economically. So it was decided to assess these impacts qualitatively by allowing experts to draw up a list of criteria on the importance of, say, the landscape surrounding airports, and then for the same experts to assign an index value along a five point scale ranging from ‘low impact’ to ‘high impact’. For example, if the areas lost to airport development contained a low biodiversity, then the ecological effects of development would simply be described as ‘low impact’. This is in stark contrast to the apparently precise monetary figures calculated for noise and emissions impacts.
Thus, the ‘Valuing the External Costs of Aviation’ report dealt with the environmental impacts (chiefly the effect of aviation emissions on climate change) by proposing to internalise the total environmental costs by eventually adding an approximate £3 levy on short-haul flight costs and a £20 levy on long-haul flight costs per passenger. It was assumed that the ‘stimulus to demand from the growth of low cost airlines and from increased airline competition could be sufficient to offset the suppressing effect [on passenger numbers] of any new environmental charges’.
But none of the research explained in detail how the funds raised would be used to repair and/or compensate for the various environmental impacts of airport expansion and associated effects. Some suggestions included paying for schoolchildren in areas surrounding airports to have regular day-trips to ‘quiet’ areas to compensate for the daily disruption they experienced as a result of the aircraft noise. Other questions were left unanswered; for example how the levy was going to compensate the millions of people potentially affected by aviation’s contribution to climate change.