Asthepopulationoftheplanetincreases，sodoesthenumberofhomes，businesses，parkinglots，schools，airportsandroadways．Allthesestructuresuseelectricityandneedtobelighted．Humansdemandtheselights．Theywanttheirhomesm

　　As the population of the planet increases，so does the number of homes，businesses，parking lots，schools，airports and roadways．All these structures use electricity and need to be lighted．Humans demand these lights．They want their homes more comfortable and they want their streets safe．The problem is that researchers are finding that all the light is having a negative effect on humans and wildlife as well．

　　Less than 10years ago I drove to a thinly populated section of my town，lay down in the middle of the road and watched an attractive meteor shower （流星雨）．The area was short of homes，street lights and traffic．If I did that today，I wouldn't be able to see the meteor shower as well．Due to the increase in street lights，I would surely be run over by a car．

　　Nowadays scientists are finding light pollution can be almost as bad as carbon dioxide pollution．If you've ever taken a flight at night，the view is beautiful，but you must remember that all the light you see wastes electricity．The crew of the space shuttles see an even bigger picture of how extensive the wasted electricity is worldwide．

　　One of the saddest parts of light pollution is that most of it is unnecessary and most of the outdoor light that we use is wasted．One only needs to look at a row of street lights to see how much of the light shines upwards and lights the sky：a total waste of electricity．

　　Besides，somewhere electricity needs to be produced，and the production of electricity creates pollution by releasing greenhouse gases．This affects the air we breathe and our quality of life．

　　Scientists are also studying the effects of light pollution on wildlife．Thousands of birds die each year when they crash into highly lighted buildings，as they become puzzled by the light．It has been long known that tiny baby sea turtles become lost and follow lights on the shore instead of heading towards the sea．

　　Fortunately，light pollution is one of the easiest sources of pollut