Take the calculation further: flying a fully laden A380 is, in terms of energy, like a 14km (nine-mile) queue of traffic on the road below. And that is just one aircraft. In 20 years, Airbus reckons, 1,500 such planes will be in the air. By then, the total number of airliners is expected to have doubled, to 22,000. The huge airplane alone would be pumping out carbon dioxide (CO2) at the same rate as 5 million cars.
男枪符文That may not em much compared with the 60 million vehicles that pour off asmbly lines every year—or the 1 billion vehicles already on the world's roads. But whereas cars are ud roughly for about an hour or so a day, jet airliners are on the move for at least 10 hours a day. And they burn tax-free, highoctane (1) 高能量的) fuel, which dumps hundreds of millions of tonnes of CO2 into the most nsitive part of the atmosphere.
Aviation is a relatively small source of the emissions blamed for global warming, but its share is growing the fastest. The evidence is strong. As a result, aviation is increasingly attracting the attention of environmentalists and politicians. Amid much controversy, CO2caps (最高限制) and carbon-trading could soon be ud to help curb aircraft emissions.
Frequent flyers, free riders
实习日志模板Airlines are accud of having a free ride in terms of air pollution becau they pay no tax on the fuel they u for international flights. Even though today's aircraft are about 70% more efficient than tho of 40 years ago, concerns over emissions have grown. Despite
booming demand for air travel, many airlines are losing money. Now green campaigners want people to think twice before they fly. The opposing voice is particularly loud in Europe, where low-cost carriers are expanding fast on busy shorthaul (2) 短距离) routes. The European Parliament will vote in July on a proposal to limit aircraft emissions.
America is deeply unhappy at the prospect of its airlines being affected. Sharon Pinkerton, a nior reprentative of the Federal Aviation Administration insisted, on a visit to Brusls last year, that American carriers should be exempted from the scheme. This ts the scene for another transatlantic aviation dispute, to add to the two bitter and long-running disputes over subsidies to Europe's Airbus and the liberalisation of air traffic between the two continents.
理财的重要性The airlines are growing nervous. The big international carriers reprented by the International Air Transport Association (IATA) would rather Europe waited for the deliberations of a United Nations body, the International Civil Aviation Organisation (ICAO), which has t technical, legal and safety rules for more than 50 years. Internation
al aviation was excluded from the Kyoto protocol on global warming, but only on condition that, by theend of 2007, countries and airlines worked under the umbrella of ICAO to come up with a way of reducing emissions through a trading scheme.
Soon after the end of the Second World War the member governments of ICAO agreed that airlines should be free of fuel taxes. Some say this was to outlaw unilateral taxes that could distort markets, but others reckon it was done to boost the fledgling airline industry emerging from the fighting. The corollary was that aviation, unlike motor traffic and other forms of transport, would pay in a transparent manner for the infrastructure and rvices it required-air-traffic management, landing charges, flyover rights and so on. That was suppod to take care of the external costs. But no one in tho days thought much about the environment. Counting the cost It was not until 1999 that the United Nations Intergovernmental Panel on Climate Change (IPCC) attempted to reduce the effect of aviation on the environment. Transport as a whole was judged to be responsible for about a quarter of the world's CO2 discharges. That makes it one of the biggest sources, alongside power generation and houholds, as a source of the gas. Within transport, avi
ation accounts for about 13%. Its contribution to total man-made emissions worldwide is said to be around 3%. So why all the fuss about so little? One reason is that high-altitude emissions are probably disproportionately damaging to the environment. The nitrogen oxides from jet-engine exhausts lead to the formation of ozone, another greenhou gas. Contrails (飞行云) are also suspected of enhancing the formation of cirrus clouds, which some scientists think adds to the global warming effect. The IPCC estimated that the overall impact on global warming of aircraft could be between two and four times that of their CO2 emissions alone, though there is no scientific connsus about the size of this multiplier.
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