Define natural pollutants
~Substances that occur naturally + are usually present in the enviroment
~Don't cause any problems
Air naturally contains...
Carbon dioxide (made by respiration,volcanoes + combustion)
Sulphur dioxide (made by volcanoes)
Nitrogen oxides (made when lightning reacts nitrogen+oxygen in the air)
Sulphur dioxide can...
reflect radiation from the Sun away so less energy reaches the Earth's surface
Rainwater has a natural pH of...
5.6 - 5.9 (mild acid)
Rainwater is acidic because...
Carbon dioxide,Sulphur dioxide,and Nitrogen oxides dissolve in the water to form acids
The ph of rainwater can decrase further if...
more acidic gases are added to the atmosphere
Acid rain has...
a pH between 3 and 5.5
A cause of acid rain is...
air pollution from burning fossil fuels
Main sources of air pollution are...
power stations and cars
Power stations and cars...
both release high amounts of CO2,sulphur dioxide and nitrogen oxides
What are the main contributers to acid rain?
Sulphur dioxide and nitrogen oxides
What damage does acid rain cause to our enviroment?
~Metals+carbonate rocks(e.g. limestone and marble) react quicker+corrode
~Plants+water life are harmed
~Damage to plants can affect animals further up the food chain
How can pollution by acid rain be reduced?
~Reducing sulphur content in petrol+diesel (so less sulpur dioxide is produced by combustion)
~Fitting CATALYTIC CONVERTERS in car exhausts (which change corbon monoxide+nitrogen oxides) into less harmful gases
(e.g. carbon dioxide and nitrogen)
~Fitting SULPHUR PRECIPITATORS in the chimneys of power stations (to remove sulphur dioxide)
How to do monitor air pollution?
~Through a network of AIR-QUALITY MONITARING STATIONS
How is air pollution measured?
~A range of POLLUTANTS are measured (e.g. rain water pH)
Monitoring air pollution through nature also gives us...
a good idea of the overall health of the enviroment
How could we help reduce pollution?
~By burning LESS FOSSIL FUELS
What is the greenhouse effect?
~When gases (e.g. carbon dioxide) trap heat energy in the Earth's atmosphere, warming it up
If greenhouse effect didn't exsists...
the world would be much colder than it is.
What has happened to the mean world tempurature over the last 100 years?
There has been a slow but steady increase
The rising mean world temp. has been linked to...
an increase of CO2 levels
How do scientists predict changes in temp.+climate?
By using computer models
What do most scientists agree on?
That the mean world temp. will have a greater increase in the future
If global warming does happen...
it will cause changes in weather + rising sea levels
The increase levels of CO2 has been linked to...
~An increase in the burning of fossil fuels
~The destruction of large forests
Why is 'climate change' more accurate than 'global warming'?
~Although the WORLD MEAN TEMP. would increase...
~...in some places, it would get colder