文章作者 100test 发表时间 2007:10:26 12:33:32
来源 100Test.Com百考试题网
It s too easy to mock His Royal Highness. in England it s practically the national sport. But his critics may be onto something. Jets are uniquely polluting, and the carbon they emit at high altitudes appears to have a greater warming effect than the same amount of carbon released on the ground by cars or factories. On an individual level, a single long-haul flight can emit more carbon per passenger than months of SUV driving. Though air travel is responsible for only 1.6% of total greenhouse gas emissions, according to one estimate, in many countries it s the fastest-growing single source--and with annual airline passengers worldwide predicted to double to 9 billion by 2025, that growth is unlikely to abate. The Intergovernmental Panel on Climate Change (IPCC) put it bluntly last year: "The growth in aviation and the need to address climate change cannot be reconciled."
One of the biggest problems, as the IPCC points out, is that the carbon emitted by air travel currently has "no technofix." As messy a source of pollution as electricity generation and ground transportation are, technologies do exist that could drastically cut carbon from power plants and cars. Not so for planes: the same aircraft models will almost certainly be flying on the same kerosene