reprinted from:
Warning about increasing effects of air travel on global warming
Copyright 2002
Deutsche Presse-Agentur HAMBURG - Concerns are increasing about the effects of air travel on global warming. It is estimated that one ton of carbon dioxide pollution is discharged for every 4,000 passenger miles. Carbon dioxide is the main greenhouse gas. Greenhouse gases are regarded as the main reason for global warming, the so-called greenhouse effect. An environmental charity, Environ, says a modern jet also emits nitrous oxide and water vapour, which at the high altitudes flown by jetliners cause twice as much global warming as carbon dioxide. Research to find alternative fuels for air travel is taking place. Fuel from plants and other organic material are the main viable alternatives. The International Friends of Nature says that the worldwide increase in air travel - it is doubling every ten years - is a serious threat to the global climate. Within the next decade, air transport may catch up with motoring as the principal climate killer. Throughout the world, more than two billion passengers and 42 million tons of cargo are carried by air every year. The number of passengers is increasing by eight per cent a year, the volume of cargo is rising by 13 per cent a year. Tourism accounts for half the mileage travelled. The number of short-distance flights, especially damaging to the environment, has been increasing out of proportion: 40 per cent of all flights are less than 800 kilometres (480 miles). Air transport uses 6 per cent of global oil consumption and 3 per cent of the carbon-dioxide pollution of the atmosphere. These figures may seem small but they are not - especially when it is considered that only 6.5 per cent of the world population travels by air. Another factor: the effect of greenhouse gases is stronger at altitudes between 9,000 and 13,000 metres (between 28,000 feet and 40,000 feet) than at lower altitudes. Pollutants in those rarified levels remain in the atmosphere for six months, 500 times longer than lower down. Their impact on the climate is increased by low temperatures - one litre of fuel burnt in the atmosphere is twice as harmful as the same amount burned near the surface. Among immediate measures called for by the International Friends of Nature is a special aviation-fuel tax which would be increased so that it becomes twice as high as petrol tax. It also proposes emission-related charges for take-offs and landings and for the income to be used for climate protection. It believes that all flights off less than
700 kilometres (420 miles) should be discontinued. |
