英语流行话题听力:Unit91 南极洲还是最后一片净土吗?

Unit 91
　　Antarctica, Is It the Last Pure Land?
　　Although tourism to Antarctica is still small by global standard, it is growing. But even the few people going there are damaging the environment, say scientists. And because of this scientists want to put an end to travel to the region.
　　Most travel firms in the area have signed up to self-imposed regulations on pollution, waste removal and other responsibilities, but like any popular tourist spot, pressures on the environment are starting to destroy the very natural beauty which attracted visitors in the first place.
　　The fact that Antarctica is also an essential spot for scientists monitoring global environmental change is also a reason people are calling for an end to tourism there. Tourists are simply getting in the way of the research.
　　For the British Antarctica Survey (BAS) the biggest concern is safety. BAS is a 60-year-old Cambridge-based project, which has carried out the majority of scientific research on and around the continent. "This year we will probably have four to five large ships with 1,000 people on board coming to Antarctica. Several of those ships are not ice strengthened," says John Shears, the environmental officer of the BAS. "If there is an accident or a ship hits an iceberg, there would be problems with health and rescue operations in the area." Shears adds.
　　The International Association of Antarctica Tour Operators is a worldwide organization based in the US for companies operating tours to the region. It promotes and practices safe and environmentally responsible Antarctic tourism. It has strict regulations for its members, but many tour ships are outside the organization. "We need strong safety regulations, controls and shipping standards to protect all tourists going to this area," says Frank Samule, a member of the association.
　　Some attempts are being made to meet Samule's wants. BAS and the British government are attempting to control all ships in the area with new shipping rules. So far though, the impact of tourism on the environment has been small and threats from man-made pollutants and the loss of the ozone layer over Antarctica are greater concerns. But researcher fear that ships and tourists could bring in plant and animal species new to the area which could harm the environment. Of greatest concern is the possibility of global, regional and local threats interacting in unexpected ways to have a significant impact on the Antarctic environment. The complex nature of th global environment means science cannot predict such event.