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1、unit3EnvironmentalPrunit3EnvironmentalProtectionotectionOur topic What do you know about greenhouse effect? Global warming? Rising sea levels? The impact on the earth?Outline Greenhouse effectGlobal warmingRising sea levelsGreenhouse effect What is the greenhouse effect ?On a sunny winter day, you p
2、ark your car in the sun, lock it, and go cruise the local shopping mall for a couple of hours. When you come back later and get into your car, what do you notice? Is the interior of the car hot or cold? How does the temperature inside of your car compare to the temperature outside? If you have ever
3、been inside of a greenhouse, especially when the sun is out, what have you observed? It is definitely warm, and usually the air is moist. A greenhouse is commonly warmer than the outside air because a greenhouse has the ability to trap heat inside of it. This phenomenon is called the greenhouse effe
4、ct.Greenhouse effect The heat caused by infrared radiation is absorbed by greenhouse gases such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere. Although greenhouse gases make up only about 1 percent of the Earths atmosphere, they regulate our climate by
5、 trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.Life on the earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planets surface an
6、d is reflected upward again as a type of slow-moving energy called infrared radiation.Greenhouse effect The greenhouse effect is a naturally occurring process that aids in heating the Earths surface and atmosphere. It results from the fact that certain atmospheric gases, such as carbon dioxide, wate
7、r vapor, and methane, are able to change the energy balance of the planet by absorbing longwave radiation emitted from the Earths surface. Without the greenhouse effect life on this planet would probably not exist as the average temperature of the Earth would be a chilly -18 Celsius, rather than the
8、 present 15 CelsiusGreenhouse effect How Do Humans Contribute to the Greenhouse Effect?While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.The problems begin when human activities distort and accelerate the natural pr
9、ocess by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.Greenhouse effect Burning natural gas, coal and oil -including gasoline for automobile engines-raises the level of carbon dioxide in the atmosphere.Some farming practices and land-
10、use changes increase the levels of methane and nitrous oxide.Greenhouse effect Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or c
11、ut down to make way for farming, however, there are fewer trees to perform this critical function.Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and global warming that is currently under way.Greenhouse
12、 effect Ultimately, more greenhouse gases means more infrared radiation trapped and held, which gradually increases the temperature of the Earths surface and the air in the lower atmosphere.Population growth is another factor in global warming, because as more people use fossil fuels for heat, trans
13、portation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere Global warming What is the global warming?Global warming is the continuing rise in the average temperature of Earths atmo
14、sphere and oceans. Global warming What is the impact of global warming? Such an unusually rapid rate of change would affect fundamental Earth systems upon which our very lives depend (R)C including ocean circulation and the hydrological, carbon and nutrient cycles. It would disrupt the natural and m
15、anaged ecosystems that provide us with water, food and fiber. It would add to existing environmental stresses such as desertification, declining water quality, stratospheric ozone depletion, urban air pollution and deforestation. _”How will global warming affect our world” (the booklet of PICC)Refer
16、ence: http:/ http:/www.ipcc.ch/Global warming 1.Spread of diseaseAs northern countries warm, disease carrying insects migrate north, bringing plague and disease with them. Indeed some scientists believe that in some countries, thanks to global warming, malaria has not been fully eradicated. 2. Incre
17、ased probability and intensity of droughts and heat wavesGlobal warming 3.Polar ice caps meltingThe ice caps melting is a four-pronged danger. (the leftside picture )4.More floods (the rightside picture)Flooding represents one of the most dangerous hazards to human settlements and is one of the most
18、 potentially momentous impacts of global warming. Global warming 5. Desertification6.TsunamisAlthough global warming does not directly influence the formation of tsunamis, they can be generated by events that are brought about by an amplification of the planets temperature. Global warming 7. Cold Wa
19、vesMore than 150 people lost their lives during the 2009 to 2010 winter after record low temperatures and abundant snowfall caused disruption to much of Europe which doesnt take into account the many thousands more excess winter deaths that were caused indirectly. It was the UKs coldest winter for t
20、hree decades. 8. Increased volcanic activityMelting glaciations can usher in new, more frequent and more dangerous episodes of volcanic activity. Global warming 9. Loss of biodiversity and animal extinctionLoss of habitat for polar-ice edge communities such as polar bears is perhaps the most obvious
21、 consequence of having a warmer climate. 10. Death of ocean lifeGlobal warming 11.Warmer waters and more hurricanes12.Economic consequencesMost of the effects of anthropogenic global warming wont be good. And these effects spell one thing for the countries of the world: economic consequences. Hurric
22、anes cause billions of dollars in damage, diseases cost money to treat and control and conflicts exacerbate all of theseGlobal warming 13.Fires and wildfiresAs the planet continues to warm, dry areas of land that are already susceptible to wildfires are likely to be ravaged by even more frequent and
23、 destructive episodes. In 2007, more than 3,000 fires brought destruction to Southeastern Europe thanks to a long summer that created arid and parched conditions a situation that would become normal as a consequence of the greenhouse effect. 14.Destructive stormswarmer oceans make for more extreme w
24、eather including devastating storms. Global warming 15. Death by smogA powerful combination of vehicular fumes, ground-level ozone, airborne industrial pollution and the stagnant hot air associated with heat waves, smog represents an immediate and chronic health threat to those living in built-up ur
25、ban areas. 16. More dangerous thunderstormsA consequence of the increased amounts of humid air generated by global warming is that more thunderstorms will be triggered. Global warming 17. Animal attacksAnimals that are driven from their natural habitats or normal migration routes by environmental fa
26、ctors could easily come into contact with human settlements, leading to many deaths among humans and already endangered animals. 18. Diminished food and water suppliesRising sea levels What is the rising sea levels?Rising Sea Levels is a global sea levels rising phenomenon caused by the temperature
27、effect on the oceans, the melting of ice sheets and glaciers, and changes in groundwater storage. Rising sea levels The impact of climate change on the Antarctic Peninsula is evident in new satellite data, US researchers say. The collapse of the Larsen B ice shelf has accelerated the flow of glacier
28、s into the nearby Weddell Sea in 2002.The Antarctic Peninsula has seen some of the fastest temperature rises on Earth in the last five decades. The scientists used a variety of data from satellites to track the speed of the glaciers before and after the collapse of Larsen B. In one study, Ted Scambo
29、s of the National Snow and Ice Data Center in Boulder, US, analysed five images taken by the Landsat 7 satellite between January 2000 and February 2003. The analysis reveals that four glaciers flowing into the now collapsed section of Larsen B increased in speed by between two and six times over the
30、 study period. If anyone was waiting to find out whether Antarctica would respond quickly to climate warming, I think the answer is yes, said Dr Scambos.Rising sea levels The second report, by Eric Rignot of the US space agencys Jet Propulsion Laboratory in Pasadena, US, showed an eightfold increase
31、 in the speed of three glaciers, called Hektoria, Green and Evans, between 2000 and 2003. Two others, Jorum and Crane, moved twice as quickly at the beginning of 2003 than they did in 2000 and nearly three times as fast by the end of the year. These two papers clearly illustrate, for the first time,
32、 the relationship between ice shelf collapses caused by climate warming, and accelerated glacier flow, said Dr Rignot. The extra ice presumably translates into higher sea level. But how much this is raising the level of the oceans isnt known.Rising sea levels The influence of rising sea levels is ve
33、ry serious, sea levels rising to the harm of human environment is shown as: the coastal land area of narrow, furniture of coastal erosion, flood and flooding caused by town, salt water intrusion and so on.About climate change report found that by 2100 the sea level could rise 1 m or higher, at least
34、 not less than 50 centimeters. About 10% of the worlds population (600 million) in a flooded the danger even if it is the lowest water level rises. Rising sea levels For exampleAccording to the development trend and the sea level rose sharply, the Indian Ocean and the maldives in the Pacific island
35、countries TuWaLu etc will be submerged, Calcutta, dhaka and other coastal cities will be destroyed. City of London, New York, and Shanghai will be forced to cost billions of dollars of funds for flood control.Rising sea levels The left one is the arctic Greenland 1992 years the area of the melting i
36、ce. 2002 years is among the area of the melting ice. Right is the area of the melting ice in 2005. So we will have to go to map the world.Rising sea levels If Greenland or melting Greenland and west Antarctica each melting half, Beijing and Shanghai are supposed to disaster. Above is a flooded area
37、of Shanghai, there will be 40 million people affected. Below, Beijing will have affected millions of people.Rising sea levels If Greenland or melting Greenland and west Antarctica each half melted and the world will be there will be many coastal city was under water scene.Rising sea levels The India
38、n Ocean tsunami site: Sea-level rises not only covered the coastal land, but the tsunami, such as Marine disasters ,the storm is more likely to occur, and the loss is bigger.Rising sea levels The United States beaches all happened more than a shark sighting, may be due to the offshore warming waters, seals a population, shark family people more ran to the offshore areas hunting.Rising sea levels What can we do?Thanks for your listening!结束结束
