教学ppt课件 unit9 Saving the earth.ppt

Watch and Listen Look and Think war Contaminated/ polluted drinking water Industrial water pollution Polluted water/ water pollution Polluted water/ water pollution/ oil pollution Exxon Valdez Oil Spill in Alaska, 1989 ??????????????????????????????????????????????????????????????????????????????????????????? Workers wash the shoreline on Latouche Island, Alaska, after the Exxon Valdez oil tanker ran aground in 1989, dumping more than 38 million liters (more than 10 million gallons) of oil into Prince William Sound. deforestation Satellite Images of Deforestation These satellite images show the same section of a Brazilian rain forest found along the Amazon river taken in 1975, left, 1986, center, and 1992, right. Over a 17-year period, among the human activities leading to this widespread deforestation are commercial logging, agriculture, mining, and oil exploration as well as small-scale activities, such as slash-and-burn agriculture, charcoal production, and firewood collection. Fire is used as the primary means to clear forests for agriculture and development, a dangerous method that frequently escapes control and destroys large areas of forest. Watch and listen desertification The area of desert is growing. desertification Desert near the Dunhuang Cave Buddhist Cave Art In Dunhuang ???????????????????????????????????????????? desertification Population growing Starvation Air pollution From air to water exhaust = send out, atmospheric moisture 水气 sulfurous 硫, nitric氮, carbonic 碳, acid 酸性物, sparse foliage 稀少的树叶, photosynthesis 光合作用, ecosystem 生态系统, organism 有机物 Global warming dust storm Chernobyl’ Decontamination Effort （切尔络贝利的清污行动） On April 26, 1986, one of the nuclear reactors at the Chernobyl’ nuclear power plant in Ukraine went off, sending out about 100 to 150 million curies(居里) of radiation into the atmosphere. In the following weeks, clean-up people worked to control the damage and reduce emissions(放射) from the radioactive debris(放射性残骸