伦敦烟雾事件课件

1、The Great Smog of 1952A history of smogHow the smog of 1952 formedImpacts of the smogResponse to the smogWhen nightfall came, however, the fog thickened. Visibility dropped to a few metres. Britain has long been affected by mists and fogs, but these became much more severe after the onset of the Ind

2、ustrial Revolution in the late 1700s. Factories belched gases and huge numbers of particles into the atmosphere, which in themselves could be poisonous. The pollutants in the air, however, could also act as catalysts for fog, as water clings to the tiny particles to create polluted fog, or smog.When

3、 some of the chemicals mix with water and air, they can turn into acid which can cause skin irritations, breathing problems, and even corrode buildings. Smog can be identified easily by its thick, foul-smelling, dirty-yellow or brown characteristics, totally different to the clean white fog in count

4、ry areas.A history of smogHow the smog of 1952 formedThe weather in November and early December 1952 had been very cold, with heavy snowfalls across the region. To keep warm, the people of London were burning large quantities of coal in their homes. Smoke was pouring from the chimneys of their house

5、s.Under normal conditions, smoke would rise into the atmosphere and disperse, but an anticyclone was hanging over the region. This pushes air downwards, warming it as it descends. This creates an inversion, where air close to the ground is cooler than the air higher above it. So when the warm smoke

6、comes out of the chimney, it is trapped. The inversion of 1952 also trapped particles and gases emitted from factory chimneys in the London area, along with pollution which the winds from the east had brought from industrial areas on the continent.During the period of the fog, huge amounts of impuri

7、ties were released into the atmosphere. On each day during the foggy period, the following pollutants were emitted: 1,000 tonnes of smoke particles, 2,000 tonnes of carbon dioxide, 140 tonnes of hydrochloric acid and 14 tonnes of fluorine compounds. In addition, and perhaps most dangerously, 370 ton

8、nes of sulphur dioxide were converted into 800 tonnes of sulphuric acid.backResponse to the smogA series of laws were brought in to avoid a repeat of the situation. This included the Clean Air Acts of 1956 and 1968. These acts banned emissions of black smoke and decreed residents of urban areas and

9、operators of factories must convert to smokeless fuels.People were given time to adapt to the new rules, however, and fogs continued to be smoky for some time after the Act of 1956 was passed. In 1962, for example, 750 Londoners died as a result of a fog, but nothing on the scale of the 1952 Great S

10、mog has ever occurred again. This kind of smog has now become a thing of the past, thanks partly to pollution legislation and also to modern developments, such as the widespread use of central heating.The New energy vehicles 这就是伦敦的自我救赎之路。“伦敦烟雾事件”已成久远的历史，但它对今天的人们仍具有强烈的警示意义： 发展经济不能以污染环境为代价，否则类似“伦敦烟雾事件”这样的生态悲剧必将重演。Go out wearing masksDo not open the window in the haze weather Light diet and drink