1. The Atmosphere 4000 Million Years ago The Atmosphere Today
NO Oxygen
Carbon Dioxide
Nitrogen and water vapour
Small amounts of methane and ammonia.
The Atmosphere 3800 million years ago
Most water Vapour lost
Carbon Dioxide levels start to drop
Carbonates form layers of sediment on the sea bed
Earth COOLED. Water CONDENSED and fell as rain forming oceans. CO2 dissolves in oceans so the levels dropped.
Volcanoes poured out lava and gases, these formed the earths atmosphere
Scientist are not sure how life began. But the first living things (green plants and algae) took CO2 from atmosphere and released
OXYGEN
Marine animals also form. When plants and animals die and fall to the ocean floor, buried under layers of sediment, get compressed and form fossil fuels
PHOTOSYNTHESIS
Carbon dioxide + Water -> Sugar + Oxygen
Oxygen reacted with the ammonia and methane
Most of the Carbon Dioxide gets locked in fossil fuels (COG) and sedimentary rock
Methane + Oxygen -> Carbon Dioxide + water
Ammonia + Oxygen -> Nitrogen + Water
The Atmosphere Today
21% Oxygen
78% Nitrogen
1% Other Gases
Small amount of CO2
The Atmosphere 2200 Million years ago
Slow increase in Oxygen levels
Nitrogen levels increase
Carbon dioxide levels falling slowly
Plankton – crude oil and gas
Plants – coal
Shells and skeletons - limestone

2. + Burning fossil fuels Carbon dioxide is a green house gas
Global warming & climate change
The graph below shows how the earth’s temperature has increased over the past 100 years.
This could be because of more pollution from factories and cars. Human factors like deforestation, more agriculture and more landfill.
Combustion (burning) of fossil fuels (coal, oil, gas) produces carbon dioxide and sulphur dioxide.
Both gases have devastating effect.
water
fossil fuels +
oxygen
->
carbon dioxide
Greater use of fossil fuels releases more CO2, deforestation means less green plants to use the CO2, farm animals produce methane, more land fill is creating CO2 from decomposition means there is more carbon dioxide in the atmosphere. This leads to global warming.
Global warming causes climate change. It also has effects such as melting icecaps, which effect polar bear populations, rising sea levels and increased coastal erosion. Changes in the temperature profile will change wind rainfall patterns and storms. This will affect food, water and distribution of species.
Temperature and CO2 level have the same patterns over time.
Carbon dioxide is a green house gas
1. Energy from the sun (shorter wavelengths) passes through the atmosphere.
3. Green house gases radiate this heat in all directions, including back to Earth.
2. Earth’s surface radiates longer wavelength heat back out to space.
Green house gases like CO2 , methane and water vapour create the green house effect, by trapping heat and causing the earths temperature to rise.
Evidence for climate change has been peer reviewed and so is reliable. As there are lots of variables, predictions are complex and so media reports can speculate and be biased.

3. Reducing the Carbon Footprint
Carbon footprint is a measure of the amount of CO2 and methane produced over the lifecycle of something, and so is very difficult to measure (lots of factors, like all the parts used to make something, making it, using it and disposing of it. It is easier to reduce the amount of CO2 and methane produced
Using nuclear and renewable energy sources and not fossil fuels
Eating less beef
Sending less waste to landfill by recycling more
Charging more tax on polluting vehicles and companies
Using biofuels (plant products burnt as fuel)
Capturing CO2 produced in power stations and storing it in rocks
Alternative technologies need to be more efficient and reduce CO2 more.
Countries need to ensure any changes do not adversely affect economic growth and well being of the populations.
International agreements are
difficult. Some do not want
to sacrifice economic
development.
Major changes will need
global agreement.
Individuals need to
change their lifestyles
and they may not
want to.
CO2
CH4
CO2
CO2
CO2
CH4

4. Burning fossil fuels Sulphur dioxide causes acid rain
1. When fossil fuels are burnt they release Sulphur Dioxide (SO2)
Combustion (burning) of fossil fuels (coal, oil, gas) produces carbon dioxide and sulphur dioxide.
Both gases have devastating effect.
2. This SO2 reacts with the water and oxygen in the air to form Sulphuric Acid H2SO4 (acid rain)
When fuel is burned in a car, not only is carbon dioxide produced (main greenhouse gas), but also carbon monoxide (incomplete combustion, not enough oxygen) and soot (carbon particles).
Effects of acid rain
Damages limestone buildings
Strips trees
Water toxic so kills fish
Sulfur impurities can be removed from fuel before it is burned (petrol, diesel, gas) or is also removed from the waste gases (coal)
Carbon monoxide (CO), colourless, odourless, toxic. Binds better to red blood cells than oxygen does, so these cells carry CO instead of O2. Drowsy, unconsciousness, death.
Fuel at high temperature e.g. car, can cause nitrogen to react with oxygen, forming nitrous oxides (oxides of nitrogen). These are toxic, can trigger asthma and also causes acid rain.
Diesel cars burn hydrocarbons with longer chains, and so do not always completely combust. Carbon and unburned fuel are also produced. These particulates can reach the upper atmosphere, where they can reflect sunlight, causing global dimming.
Global dimming can also be caused by smog (a mixture of smoke and fog), blocking sunlight