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Greenhouse effect. The greenhouse effect is a natural process that is vital for life on earth (without it earth would be 30 º C cooler). But since the industrial revolution the production of CO 2 has increased dramatically.
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The greenhouse effect is a natural process that is vital for life on earth (without it earth would be 30ºC cooler). • But since the industrial revolution the production of CO2 has increased dramatically. • This means that more heat is prevented from leaving the earth’s atmosphere. Most scientists now agree that the Earth’s temperature is increasing.
Reasons behind the increase in Greenhouse gases • Combustion of fossil fuels – due to high energy demand. • Deforestation (less photosynthesis) • Large scale farming (cattle - methane)
Effects of Global warming • Ice caps melt – rise in sea levels • Low lands flood • Climate change • Floods, hurricanes, monsoons • Species extinction • Drought • Food shortages
Acid Rain • Fossil fuels contain impurities such as Sulphur. When we burn the fuel the sulphur is oxidised and it turns into Sulphur dioxide (SO2) gas. • The gas dissolves in rain water and reacts with oxygen in the air to form sulphuric acid.
Acid rain is also formed by nitrogen oxides (from cars) dissolving in water to form nitric acid.
Catalytic Converters in Cars • Reduce amount of Nitrogen Oxides (NO and NO2) released by cars. • Reduce amount of Carbon monoxide released by cars.
A B Catalyst used: Platinum, rhodium or palladium A: Nitrogen Oxide is reduced To produce Nitrogen and Oxygen. e.g. 2NO(g) N2 (g) + O2 (g) B: Carbon monoxide is oxidised to produce Carbon dioxide. e.g. CO(g) + O2(g) 2CO2 (g) The catalyst has a honey comb/ bead like structure – why?
Acidic gases are also produced in factories and power stations. • What can be done to prevent these gases? (See pg 188)
Task • Put together a cartoon explaining how acid rain is formed, the effects of acid rain and what can be done to prevent it. • Use page 188 on your books