1. MODULE C1: AIR QUALITY OCR 21 ST CENTURY SCIENCE

2. 4 Billion years3 Billion years2 Billion years1 Billion yearsPresent day Evolution of the Earth’s Atmosphere Carbon dioxide MethaneAmmoniaOxygenNitrogenOthers Present day atmosphere contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO 2

3. Formation of oil and gas 1) Layers of dead sea _____ settle on the seabed. 2) Layers of __________ rock build up on top. 3) The heat and ________ from these rocks, along with the absence of ______, mean that oil and gas are formed over ______ of years. Words – sedimentary, millions, oxygen, creatures, pressure

4. Burning Fuels Lots of oxygen: Some oxygen: Little oxygen: C H H H H O O O O O H H O H H C O O MethaneOxygen+Water+Carbon dioxide Oxygen+ O O O O O O Methane C H H H H C H H H H Carbon monoxide C O C O Water+ O H H O H H O H H O H H C C H H H H Methane O O Oxygen+ O H H O H H Water+ Carbon

5. The Greenhouse Effect 1) Heat and light energy reach us from the sun… 2) …a lot of this heat is reflected off the Earth’s surface… 3) …some of the heat escapes back into space… 4) …while some of it is reflected back to the Earth – this is called The Greenhouse Effect

6. Acid Rain Acid rain damages trees and buildings and can harm wildlife. What causes it? Sulphur dioxide from volcanoes Carbon dioxide and sulphur dioxide from power stations Oxides of nitrogen S O O H H O S O O H H O Sulphur dioxide + water sulphurous acid

7. Upsetting the balance Until recently, the environment has maintained a balance in carbon dioxide: Carbon dioxide is produced by respiration… …and used by photosynthesis Unfortunately, this balance is being upset by two main factors: 1)Excessive burning of fossil fuels… …is producing too much carbon dioxide 2)Large scale deforestation… …is slowing down the removal of carbon dioxide from the atmosphere

8. Air pollution As well as acid rain, air can be polluted by dust, pollen, compounds of lead and carbon monoxide. Nearly all of this pollution is man made, so how can we stop it? Ways of reducing pollution Develop more efficient engines Use catalytic converters in cars Use low sulphur petrol “Wash” waste gases to remove dust and particles Use lead-free petrol

9. Sustainable Development Sustainable development is all about preserving the world for tomorrow. There are three main strands: 1)Economic development 2)Social development 3)Environmental protection Examples of sustainable development include: 1)Replanting trees after chopping them down 2)Limiting the number of fish allowed in a catch 3)Protecting endangered species

10. Renewable energy sources Wind Tidal Hydro-electric Geothermal Biomass Wave

11. House insulation Draught excluders Double glazing Loft insulation Cavity wall insulation