Man and his enviroment

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