Unit 4 Global warming warming up

课件24张PPT。Global WarmingUnit 4Warming up Fossil fuel (化石燃料) : Ancient animal and plant material below the surface of the earth with a high carbon content, such as coal, oil and natural gas, which can be burnt to produce energy; also known as non-renewable energy because once they are used they have gone forever; they cannot be renewed. What are fossil fuels? From the following pictures, you will know where all this energy comes from.windmillsa coal power stationan oil refinerya nuclear power plantsolar panelsa hydro-electric damSample listslight
heating
television
cassette
player
video recorder oilcoalnatural gaswind (wind power)sun (solar energy)renewable renewable non-renewablenon-renewablenon-renewablefridgestovewashing machinehair-
dryerwater( hydro-electric)renewableplant waste (biomass energy)renewablehot springs or geysers (geothermal energy)renewablethe sea (tidal energy)renewablecomputer uranium (nuclear energy)non-
renewableRenewable or non-renewable?√Renewable or non-renewable?√What is told in the picture?non-renewable energy source Notes to Renewable energy
Renewable energy resources may be used directly, or used to create other more convenient forms of energy. Examples of direct use are solar ovens, geothermal (地温) heating, and water and windmills. Examples of indirect use which require energy harvesting are electricity generation through wind turbines(涡轮) or photovoltaic(光电的) cells, or production of fuels such as ethanol(酒精) from biomass(生物量). Renewable energy (sources) or RES capture their energy from existing flows of energy, from on-going natural processes, such as sunshine, wind, flowing water, biological processes, and geothermal heat flows. Most renewable energy, other than geothermal and tidal power, ultimately(基本上)come from the Sun. Some forms are stored solar energy such as rainfall and wind power which are considered short-term solar-energy storage, whereas the energy in biomass(生物量) is accumulated(积聚) over a period of months, as in straw, or through many years as in wood. Capturing renewable energy by plants, animals and humans does not permanently deplete(耗尽) the resource. Fossil fuels, while theoretically renewable on a very long time-scale, are exploited at rates that may deplete these resources in the near future. Homework
Review the new words and
expressions you learned in this class.
2. Preview Reading.Thank you!