Resource depletion and environmental pollution are invariably the ancillaries of economic development. Airports can contribute to air pollution through:aircraft operations, aircraft-taxiing to and from runways, re-fuelling of aircrafts, de-icing of aircraft and runways, vehicular traffic to and from airports, emissions from heating plants and power generation systems, and emissions from engine testing areas. Further, recent studies on climate have produced extremely disquieting findings about the effects of air traffic on it. These studies have shown that, at altitudes above 9,000m, even the water vapour emitted from the aircraft engines has to be regarded as a pollutant. Environmental impacts from air transportation can be mainly separated into air, water, and noise pollution. Impacts of the `man made capital' such as roads, ports, and harbours on `natural and environmental capital' such as fresh air and biodiversity have severely distorted the paradigms of sustainable development, the world over. The trends have however been more pronounced in developing countries where because of greater rates of population growth and natural resource depletion more pressures are exerted on environmental resources. As the transportation sector penetrates into the environmental setting of an area, depletion of oil resources, noise pollution, urban smog, decline in available land resources and diminished plant and animal species are the immediate consequences.

It is beyond the scope of the present document to elaborate on the comprehensive impacts of all transport infrastructure projects. Specific impacts of airport development that need to be specially considered for evaluating the impacts on natural systems deserve some elaboration. The construction of airport consumes substantial areas of land, virtually to the exclusion of any other use. In some cases, valuable agricultural and community forest lands are taken, while in other cases, areas of natural habitats are devoured or split into isolated fragments. These physical impacts pose direct threats to the integrity of wildlife habitats and thus to the conservation of wilderness species thriving within them.