Global warming by Mian Mehran Raza

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.