7 Air pollution What causes air pollution? car exhaustsemissions from industrial production (factories, power stations) - dust, smoke, smell…Which gases in the air are poisonous?sulphur dioxide (SO2)nitrogen oxide (NO)carbon dioxide (CO2)
8 What does polluted air cause? health problemsclimate changes (changes in weather patterns – ice at the North and South Pole melt, sea level rises => flooding)
9 Water pollution What causes water pollution? industrial waste chemical fertilizers and pesticidesoil refineriesaccidents of huge cargo shipsdumping toxic pollutants in the water
10 Wasteindustrial wastedomestic wastelitters in the streets
14 Why are the animals in danger? What are they hunted for?
15 some of the animals have become very rare and are threatened by extinction(red lists)some animals are protected (bats, rhinoceros,the giant pandas,...), some are bred in captivity for releasing inthe wild later, so they have the best chance of survivalto save endangered animals, it’s necessary to protect their habitats (=special places where particular animals live) from destruction, they need to live in a balanced community (eachanimal species is a memberof a food chain, if one ofthem disappears, thesystem may collapse)
16 Deforestation Why are the trees / rainforests cut down? What does it cause?
17 rainforests help to control global warming because they absorb carbon dioxide in recent years large areas of rainforests have been destroyed (trees have been cut down – land / wood is needed for farming, firewood, buildings, furniture => millions of animals and plants are killed too)rainforests grow on poor soils and when they are cut down or burned, the soil is washed away in the tropical rains, and these areas may turn to desert
18 Global warming – greenhouse effect Explain greenhouse effectglobal warming is caused by greenhouse effect
19 normally, heat from the sun warms the earth and escapes back into space several gases, so-called greenhouse gases (carbon dioxide – produced by burning fossil fuels, nitrogen oxides - from car exhausts, CFCs – chlorofluorocarbons from aerosol and refrigerators) go up into the atmosphere and with water vapour prevent heat from escapingbecause the heat can’t leave, the Earth gets warmer = global warming
20 Acid rainWhat is acid rain?What does acid rain cause?
21 the smoke which is produced by factories and cars is mixed with water vapour in the atmosphere they form sulphuric acid and nitric acidsunlight turns these acids into poisonous oxidants which fall in rain or snow onto tress and gradually kill them
22 Solution ? save energy, water use alternative sources of energy don’t use cars so muchrecycle (saves energy and raw materials, reduces damages of the countrysidesort out the waste (many cities have bottle banks and can banks)use new energy sources, alternative forms of transportbuy green products (buy environmentallyfriendly products which can be recycled)use recyclable paperuse deodorant sprays without CFCsprotest against pollution, killing animals,…
23 Alternative sources of energy What are alternative sources of energy?Why do we need them?most of the energy we use today comes form coal, oil and gas, but these will not last foreverburning them is slowly harming the atmosphere => need for new ways of supplying energy
25 SOLAR POWERusing the sun’s energy as heat or to make electricityWATER POWERgenerating hydroelectric power from river water in mountain areaselectricity can becreated from sea water flowing in and out with the tidesWIND POWER building modern windmills