4.9 Carbon Cycle

• C02+H20 are combined in photosynthesis using light energy.
• Light energy is trapped and used to form organic molecules such as glucose.
• The C02 comes from the atmosphere which makes 0.03% of the atmosphere.
• Photosynthesis is responsible for reducing the atmospheric C02.
• The passage of carbon through the various trophic level we have identified the producer
• The primary consumer takes in the carbon from the producer

4.14 increase in greenhouse gases results in an enhanced greenhouse effect and that this may lead to global warming and its consequences

- The enhanced green house effect is brought about by pollution molecules such as carbon dioxide, methane and water vapour, these are green house gases.

Water Vapor, Methane and Carbon dioxide are all greenhouse gases.
Greenhouse gases changes the climate.
The UV rays are increasingly re-emitted which warms the earth's surface.
Melting ice case, raising sea levels can happen due to Greenhouse gases.

4.13 how human activities contribute to greenhouse gases

1. FOSSIL FUELS
the combustion of fossil fuels from industries, cars and domestically
2. FARMING
cows produce methane which is a green house gas
3. CLOUDS
evaporation of water forming water vapours
4. REFRIGERATION/SOLVENTS (CFCs)
substances containing chlorine, fluorine and carbon

4.12 recall that water vapour, carbon dioxide, nitrous oxide, methane and CFCs are greenhouse gases

ENHANCED GREENHOUSE EFFECT
is when more of the greenhouse gases are produced absorbing more of the infrared reflecting out of earth and immiting it back onto the earths surface increasing the temperature further leading to climate change

CFC - Cluorofluorocarbon
effects the ozone layer which absorbs UV light making it less efficient in absorbing UV light.

UV light comes from the sun.
UV light is converted as infrared and absorbed.
50% of UV light is reflected.
The more the greenhouse gases the more heat there is.
Infrared gets emitted back out.

4.11 understand the biological consequences of pollution of the air by sulphur dioxide and carbon monoxide

SULPHUR DIOXIDE ( SO2 gas )
- is produced in the combustion of fossil fuels and also by vehicles in the combustion of petrol
- when SO2 gas is produced it reacts with water vapour in the air and forms sulphuric acid which is found in the water that condenses as clouds, this is known as acid rain.
EFFECTS OF ACID RAIN
acid rain effects plants and animals in a variety of ways

The burning of fossil fuels results in sulphur dioxide gas.
Sulphur dioxide happens mostly because of factories and cars.
Acid rain kills fish in lakes and rivers.
Carbon monoxide blocks hemoglobin which can lead to death.
S02+H20 -Sulphuric acid - Acid rain.