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1. What is ecology?

it’s a science that deals with the relations between living beings and land they live in

  • 2. How has man changed his physical enviroment through the centuries?

man changed his physical enviroment in order to improve his way of life. With the tools of technology he changed a lot of features of the earth. He has transformed woodlands and prairies into farmlands, made lakes and reservoirs out of rivers for irrigation purposes and hydroelectric power. Draining marshes, cutting through mountains to build roads and railways. Conservationists believe that it’s now necessary for man to limit the growth of technology in order to survive on the earth.

What should and shouldn’t man do to protect environment?

SHOULD

safeguard water supplies use camping sites to put up a tent leave no litter

plant new trees make fire in marked places only respect wild life respect tourist signs build sewage works

SHOULDN’T light fires in the woods wash the car in the streams drop lighted cigarettes throw rubbish in the streams pick protected flowers catch and kill rare insects and birds cut down old rare trees discharge chemicals into river catch fish without fishing license break branches of trees

Ozone hole Ozone layer is getting thinner. If people don’t protect themselves it can have harmful effects – skin cancer, blindness…

PROTECTION

When outside for long periods wear a broad brimmed hat. In bright sunlight, wear sunglasses that absorb UV rays. Sun cream with sun protection factor Wear protective clothing Stay out of the sun between 10 am and 3 pm.

EFFECTS OF THE SUN UV RAYS

Eyes – the lenses of the eyes can become clouded ® cataracts ® can cause blurry vision, blindness. Skin – prolonged exposure to UV rays can cause premature aging, wrinkling, skin cancer. Immune system Crops – it could reduce the amount of crops Sea life – UV rays affect the growth of tiny sea creatures called plankton

Greenhouse effect In the last 100 years the Earth’s surface has warmed up by more than half a degree. Even every small changes can cause very big problems. Scientists believe that sea levels will rise by up to one and half meters by the year 2020.

WHAT CAUSES THE GREENHOUSE EFFECT? Man himself is the greatest contributor. He has polluted the atmosphere with dangerous gases – carbon dioxide from fossil fuels (coal, oil, and gas), chlorofluoro carbons (aerosol sprays, refrigerators). he has destroyed many tropical rain forests.

WHAT CAN BE DONE? Dangerous gases must be reduced. Existing rain forests must be saved and new trees planted. Dams, windmills and solar energy must be exploited. another source of energy: NUCLEAR POWER In France and Belgium, they generate more than 2/3 of their electricity from nuclear power / it has helped to reduce output of carbon dioxide faster