Part 3 Enhancement of Cross-cultural Communication Abilities Passage Reading Tourism-related Pollution Tourism can cause the same forms of pollution as any other industry: air emissions, noise, solid waste and littering, releases of sewage, even architectural/visual pollution. Transport by air, road, and rail is continuously increasing in response to the rising number of tourists and their greater mobility. One consequence of the increase in air transport is that tourism now accounts for more than 60% of air travel and is therefore responsible for an important share of air emissions. One study estimated that a single transatlantic return flight emits almost half the CO2 emissions produced by all other sources (lighting, heating, car use, etc.) consumed by an average person yearly. Transport emissions and emissions from energy production and use are linked to acid rain, global warming and photochemical ( 光化学的 ) pollution. Air pollution from tourist transportation has impacts on the global level and it can contribute to severe lo cal air pollution. Some of these impacts are quite specific to tourist activities. For example, in very hot or cold countries, tour buses often leave their motors running for hours while the tourists go out for an excursion because they want to return to a comfortably air-conditioned bus. Noise pollution from airplanes, cars, and buses, as well as recreational vehicles such as snowmobiles and jet skis, is an ever-growing problem of modern life. In addition to causing annoyance, stress, and even hearing loss for humans, it causes distress to wildlife, especially in sensitive areas. For instance, noise generated by snowmobiles can cause animals to alter their natural activity patterns. In areas with high concentrations of tourist activities and appealing natural attractions, waste disposal is a serious problem and improper disposal can be a major despoiler ( 掠夺者 ) of the natural environment. For example, cruise ships in the Caribbean are e stimated to produce more than 70,000 tons of waste each year. Solid waste and littering can degrade the physical appearance of the water and shoreline and cause the death of marine animals. In mountain areas, trekking tourists generate a great deal of wast e. Tourists on expedition leave behind their garbage, oxygen cylinders ( 氧气瓶 ) and even camping equipment. Such practices degrade the environment with all the detritus typical of the developed world, in remote areas that have few garbage collection or dispos al facilities. Construction of hotels, recreation and other facilities often leads to increased sewage pollution. Waste water has polluted seas and lakes surrounding tourist attractions, damaging the flora and fauna. Sewage runoff causes serious damage to coral ree fs because it stimulates the growth of algae, which cover the filter-feeding corals, hindering their ability to survive. Changes in salinity and siltation ( 沉积 ) can have wide-ranging impacts on coastal environments. Often tourism fails to integrate its structures with the natural features and indigenous ( 本土的;固有的 ) architecture of the destination. Large, dominating resorts of disparate design can look out of place in any natural environment and may clash with the indigenous structural design. A lack of land-use planning and building regulations in many destinations has facilitated sprawling developments along coastlines, valleys and scenic routes. The sprawl includes tourism facilities themselves and supporting infrastructure such as roads, employee housing, parking, service areas, and waste disposal.