Greenhouse Effect, Natural and Enhanced温室效应增强，自然

Greenhouse Effect, Natural and EnhancedNovember 19, 2008SurveyvHave you ever seen a greenhouse? What is its roof made of?vWhich is hotter, the inside of a greenhouse or the outside?vWhat’s the average temperature of the earth?vWhat prevents the earth from getting too hot or too cold?I. Greenhouse effectvExplain the basic theory of the greenhouse effect with the help of the given words below. uheat energy, pass through, glass, heat the ground;upart of the energy, reflect, atmosphere, some, trapped inside;uinside, greenhouse, warmervThe heat energy from the sun passes through the glass and heats the ground.vThe heat energy from the ground is partly reflected into the atmosphere, but some is trapped inside the greenhouse.vTherefore, the inside of the greenhouse is getting warmer and warmer. This is the greenhouse effect.II. Natural greenhouse effect on the earth vFind similarities between a greenhouse and the earth.GreenhouseEarthheat sourcethe suntrapglass ceilingresult 1heat trappedresult 2getting warmerthe sunthe sungreenhouse gas layergreenhouse gas layerheat trappedheat trapped getting warmergetting warmervheat energy, pass through, greenhouse gas layer, heat the earthvpart of the energy, reflect, space, some, trapped in the atmospherevearth, warmvThe heat energy from the sun passes through the greenhouse gas layer into the atmosphere and heats the earth.vThe heat energy from the ground is partly reflected into the space, but some is trapped in the atmosphere.vTherefore, the earth is kept warm. This is the natural greenhouse effect on the earth.Is the natural greenhouse effect good? Why?vIt keeps the earth from getting too hot or too cold and makes the earth a comfortable place to live.Greenhouse gasesvCarbon dioxide (CO2) vMethane (CH4)vWater vapourvnitrous oxide (N2O) vetc.III. Enhanced greenhouse effectvIf the greenhouse gases continue to increase, what will happen?Video 1Video 2Video 3Global warmingnEnhanced greenhouse effectGlaciers meltingSea level risingMore typhoons and hurricanesMore floodsMore …nCauses of the enhanced greenhouse effectA: Burning fossil fuels causes increase in CO2 and other greenhouse gases.B: Living creatures, such as humans and animals, produce more methane (CH4).C: Deforestation makes it difficult to absorb the greenhouse gases.On the one hand, humans are producing more and more greenhouse gases.On the other hand, there are not enough plants to absorb the greenhouse gases.IV. The cure for the enhanced greenhouse effectChinese government’s policy: save the energy and reduce the greenhouse gas emission!What can we do?3-R PrincipleSummary: greenhouse effect—the theoryThe heat energy from the sun __________ the greenhouse gas layer into the ________ and ____ the earth. The heat energy from the ground is partly _______ into the space, but some is ______ in the atmosphere. Therefore, the earth is kept ____. This is the natural greenhouse effect on the earth. However, with the ______ of greenhouse gases, more and more heat is _____ in the atmosphere. Then, we have the _______ greenhouse effect.passes throughatmosphereheats reflected trappedwarm increasetrapped enhancedHomeworkvMake a poster to introduce the EGE and the 3-R principle;vPersuade your relatives and friends to carry out the 3-R principle. 。