Chapter 9 - Chem of Atmosphere

Main Gasses in earths atmosphere

• Same for the last 200 million years

• Nitrogen four fifths (80 percent)

• Oxygen one fifth (20 percent)

• Small amount of other gases include co2 water vapour noble gases

Formation of early atmosphere theory + formation and what is produced

• Volcanic activity gave out gas

• Went to form oceans (watervapour) ,atmosphere and co2

• Over time other gases emerged for volcanoes

Decreasing amount of co2

• Oceans are a natural store of co2 when oceans form co2 from atmosphere is dissolved into them

• Dissolved co2 when through reactions to form carbonate precipitates that formed sediment on sea bed

• Animals evolved and shell and skeletons contained co2 from the ocean which became trapped as they died

• green plants and algae evolved and absorbed co2 for photosynthesis

Locking away carbon

• When organisms die in oceans they sink into seabed and get buried under layers of sediment

• Compressed and form sedimentary rocks,oil gas by trapping carbon with them keeping levels low

• Crude oil and natural gas - plankton

• Coal - thick plant deposits

• Limestone is a sedimentary rock made from calcium carbonate and deposits from the shells and skeletons of marine organisms. Most of early co2 locked away in this

Increasing the amount of oxygen

Process of photosynthesis
- 6CO2 + 6H20 —> C6H12O6 + 6O2

Greenhouse gases

• Gases that act as an insulating layer to the earths atmosphere (co2,methane)

• Sun emits short wavelengths that pass through atmosphere and reach earth

• Earth absorbs and re emits it as long wavelength radiation

• Absorbed by greenhouse gases in atmosphere that re radiate it in all directions

• Thermal radiation resulting in warming greenhouse effect

Human activity and effect on gases

• Human population shot up become more industrialised

• Burning more fossil fuels

• More “locked up” carbon is being released into atmosphere

• Chopping forests which are used to absorb carbon dioxide 

• Increased population and increased food more cattle so more methane and more waste which ends up in landfill sites which breaks down and releases co2 and methane

• Global warming process

Consequences of climate change

• Avg temp of earth increasing leading to global warming

• Increasese in global temp can lead to polar ice caps melting rise in sea levels 

• Rainfall pattern can cause regions to get too much or too little water

Assesing risks of climate change

• Some changes will affect little people such as costal erosion on inland people (no effect)

• Some changes like food shortage can effect millions

• Some changes have short term impacts and are reversible and some are long term and permenant

Carbon foot prints

• Measure of amount of co2 and other greenhouse gases that are relsaed over the full life cycle of something

• Hard to accurately measures as there are so many things to consider

Reducing co2 footprints

• loots of co2 emissions come from burning fossil fuels so one way to reduce is using renewable energy or nuclear

• Develop more efficient processes that use less eengy so less ff need to be burnt

• Less waste could cut greenhouse gas emisisions

• Companies can charge tax on people with high emissions

• Carbon capture and storage

Problems with reducing

• Reduces the economic growth of a country

• Not everyone willing is sacrfiice and change 

• Not many people educated on why these changes are necessary

• Not everyone has good enough alternatives like renewable energy

Products of combustion

• Plent of oxygen then carbon in fuel is oxidised to carbon dioxide

• Not enough oxygen some of the carbon isnt completely oxidisied called incomplete combustion solid particles (particulates( of soot and unburnt fuel is released carbon monoxide and co2 asw well

• Sulfur impurities the sulfur will be oxidisied to produce sulfur dixoide when fuel is burnt

• Oxides of nitrogens will also form if fuels burns at high temp interal combustion of engines

Problems with co2 partiuclates

• Particulates if inhaled can get stuck in lungs and cause damage

• Lead to respiratiory problems

• Bad for environment relflect sunlight back into space and help produce more clouds

• Less light reaches earth causing global dimming

Probs with carbon monoxide

• Particulates from incomplete combustions cause problems

• Carbon monxodie cause cause blood to stop carrying oxygen around body

• Binds the haemoglobin in the blood cells that normally carries oxygen

• Lack of oxygen in blood can lead to fainitng coma or even death

• Very hard to detect as there is no smell or colour

Acid rain

• Sulfur dioxide or oxides of nitrogen mix with the water in clouds 

• React with water to form sulfuric acid or nitric acid 

• Acid rain causes lakes to become acidic and many plants and animals die as a result

• Acid rain also kill trees damages limestone buildings and stone statues

• Sulfur dioxide and nitrpgen oxides are bad for human health as they can cause respiratory problems if breathed in