photos in class 14/06/11

2.14

understand how an increase in greenhouse gases results in an enhanced greenhouse effect that may lead to global warming and it's consequences

pollution molecules are; carbon dioxide, methane, suplhur dioxide, nitrous dioxide, water vapour

these gases increase in concentration in the upper atmosphere, which raises the average global temperature (global warming)
simple ideas of the consequences are
*melting ice caps
*raised sea levels
*ocean currents changing
*winds generated elsewhere
this contributes to CLIMATE CHANGE
which changes the distribution of the worlds biomas. ecosystems
polar ice cap melt, forest distribution changes, deserts expand.

4.13

understand how human activities contributre to greenhouse gases

1. the burning of fossil fuels results in the formation of carbon dioxide nitrous dioxide and sulphur dioxode
carbon dioxide and nitrous dioxide are greenhouse gases (absorb infra red light and distribute it back in all directions, but crucially towards the earths surface
these are released from factories and vehicles-exhaust emissions. burning of coals in domestic facilities, although that is less prominent now

2. farming
animals in their digestion of crops emit methane gas into the atmosphere. cows are mainly the blame. 9 percent of methane blamed on farm animals

3. evaporation of water to form water vapour, clouds are a significant contributer to the greenhouse effect

4. refrigiration, solvents anmd propellents contain CFC's
CFC's--> chlorofluorocarbons
C, Cl (small 3) F
well associated with UV LIGHT and CATALYSING THE BREAKDOWN OF THE OZONE LAYER

4.12

objective 4.12 - recall that water vapour, carbon dioxide, nitrous oxide, methane and CFC's are greenhouse gasses

4.11

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

1. sulphur dioxide

*sulphur dioxide as a gas is released into the atmosphere when there is combustion of fossil fuels. this often occurs in factories and vehicles (oil and petrol)

*suplhur dioxide = SO2
*sulphur dioxide and water vapour (in the clouds) --> sulphuric acid
*sulphuric acid falls as acid rain
*acid rain affects plants and animals.

*trees are burned by the acid, so they die, the acid gets into the soil and this causes magnesium ions and calcium ions to be leached out of the soil so the trees cannot reach them, the trees leaves yellow and the tree dies.
*the precipitation of acid rain, it gets into streams and rivers and lowers the pH, to acid levels. this increases aluminium ions, which cause the thickening of the mucus which lines the fish gills, which reduces the fishes ability to take oxygen so in the end the fish suffocates and dies.

2 carbon monoxide
caused when fossil fuels (coal and GAS)  are burned with insufficient levels of oxygen.
fossil fuels -->(insufficient oxygen)--> CO
CO  combines with haemoglobin in red blood cells to make carbino haemoglobin, which blocks haemoglobin from carrying oxygen which reduces the circulation of oxygen arounf the body
CO is TOXIC, and is often FATAL. it causes the body to suffocate.