190 likes | 442 Views
Greenhouse Effect, Natural and Enhanced. November 19, 2008. Survey. Have you ever seen a greenhouse? What is its roof made of? Which is hotter, the inside of a greenhouse or the outside? What’s the average temperature of the earth? What prevents the earth from getting too hot or too cold?.
E N D
Greenhouse Effect, Natural and Enhanced November 19, 2008
Survey • Have you ever seen a greenhouse? What is its roof made of? • Which is hotter, the inside of a greenhouse or the outside? • What’s the average temperature of the earth? • What prevents the earth from getting too hot or too cold?
I. Greenhouse effect • Explain the basic theory of the greenhouse effect with the help of the given words below. • heat energy, pass through, glass, heat the ground; • part of the energy, reflect, atmosphere, some, trapped inside; • inside, greenhouse, warmer
The heat energy from the sun passes through the glass and heats the ground. • The heat energy from the ground is partly reflected into the atmosphere, but some is trapped inside the greenhouse. • Therefore, the inside of the greenhouse is getting warmerand warmer. This is the greenhouse effect.
II. Natural greenhouse effect on the earth • Find similarities between a greenhouse and the earth. the sun greenhouse gas layer heat trapped getting warmer
heat energy, pass through, greenhouse gas layer, heat the earth • part of the energy, reflect, space, some, trapped in the atmosphere • earth, warm
The heat energy from the sun passes through the greenhouse gas layer into the atmosphere and heats the earth. • The heat energy from the ground is partly reflected into the space, but some is trapped in the atmosphere. • Therefore, the earth is kept warm. This is the natural greenhouse effect on the earth.
Is the natural greenhouse effect good? Why? • It keeps the earth from getting too hot or too cold and makes the earth a comfortable place to live.
Greenhouse gases • Carbon dioxide (CO2) • Methane (CH4) • Water vapour • nitrous oxide (N2O) • etc.
III. Enhanced greenhouse effect • If the greenhouse gases continue to increase, what will happen? Video 1 Video 2 Video 3
Global warming Glaciers melting More floods Sea level rising More typhoons and hurricanes More … • Enhanced greenhouse effect
Causes of the enhanced greenhouse effect On the one hand, humans are producing more and more greenhouse gases. A: Burning fossil fuels causes increase in CO2 and other greenhouse gases. C: Deforestation makes it difficult to absorb the greenhouse gases. B: Living creatures, such as humans and animals, produce more methane (CH4). On the other hand, there are not enough plants to absorb the greenhouse gases.
IV. The cure for the enhanced greenhouse effect Chinese government’s policy: save the energy and reduce the greenhouse gas emission! What can we do?
Summary: greenhouse effect—the theory passes through The 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. atmosphere heats reflected trapped warm increase trapped enhanced
Homework • Make a poster to introduce the EGE and the 3-R principle; • Persuade your relatives and friends to carry out the 3-R principle.