Date post: | 14-Aug-2015 |
Category: |
Environment |
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Name. Mian Mehran Raza
Env. Sciences
Global Warming
University of Swat
What we are going to learn?
.Atmosphere
.GHG,s
.Green House Effect with example
.Causes of co2 and its sources (GHG)
.Global Warming
.Causes
.Effects
.Control/Solution
What is the atmosphere and why does it trap heat?
The atmosphere is the air around the surface of the earth. It is made from a mixture of gases. We need it for humans animals and plants to survive.
Some of the gases act like a blanket, trapping heat. These gases are called ‘greenhouse gases’ and this phenomena is known as the ‘Greenhouse Effect’. Without it, the earth would be much colder.
Which gases in the atmosphere trap heat?The atmosphere is made of 78% Nitrogen and 21% Oxygen.But these gases don’t trap heat and cause global warming or climate change.What % of the atmosphere is left?
The gases which trap heat make up less than 1% of the atmosphere! They are called the ‘greenhouse gases’.
The main greenhouse gases are:
Carbon dioxide Methane Nitrous oxide Water vapours CFC’s
Human activity increases the amount of these gases in the atmosphere
DefinitionDefinition
The average increase in earth’s The average increase in earth’s surface temperature due to surface temperature due to green green house effecthouse effect is known as global is known as global
warming.warming.
Example of the Greenhouse Effect
Natural Greenhouse effect
More heat is trapped and causes global warming
Atmosphere traps some heat
Some heat goes out to space
Some heat is trapped and the earth is warm enough for life.
Enhanced Greenhouse effect
Heat radiates from the earth
Heat radiates from the earth
Atmosphere has more greenhouse gases
Atmosphere traps more heat
Less heat goes out to space
Causes of Global Warming
CO2
• Co2 is produced by burning of fossil fuels.
• More than 6 billion tons of co2 is produced worldwide every year.
• By burning one gallon of gas 22 Million molecules of Co2 are released to the atmosphere.
• One molecule of co2 can stay 100 years in atmosphere.
Industries
Burning of fossil fuels
Increased coal, natural gas and petroleum usage.
Vehicles
Deforestation
Forest Fire
Effects
• Glaciers and polar ice caps melts
• Extra Evaporation• Extra Precipitation• Disturbs life on earth• Also disturbs life in oceans• Rivers will burst their banks• Deserts Expansion
Increase in Sea Level
Extra evaporation
Extra Precipitation
Rivers will burst their banks
Disturbs life on earth & in Oceans
Control
What we can do?
?
Control
• Using renewable sources of energy.
• Reduce our consumption of fossil fuels
• Capture Co2 at the place of production
• Reduce Deforestation & pay attention to
• Aforestation
•Reforestation
•Reducing, Recycling, Re-using
•Use of bicycle instead of vehicles
•Using public transport instead of private automobiles.
One fourth of Co2 emissions can be reduced by using properly our home appliances.
Replace your old refrigerators with new ones.
Introducing Energy Savers
Turning off lights, TV etc.