Presented to………………………………..

Engr. Qaisar Farooq

Presented by ………………………………..

Muhammad Umar HyatKhalid Mehmood Shehzad

Touqeer AslamAli Raza

Riaz AhmadIrfan Lodhra

Kashif Rasheed

GLOBAL WARMING : CAUSES AND

EFFECTS

Introduction

What is Global Warming?The rise of average temperature of earth’s atmosphere and the oceans.

Basic Questions of Global Warming

1. What causes the earth’s climate to change?

2. What are the effects of Global Warming to humanity?

3. How do we overcome this problem?

Green house gases acts like a mirror which reflect a part of heat radiation back to the earth.

The sun sends out energy as heat and light. This energy comes to our earth during the day time.

Some of the sun’s rays get ‘trapped’ in the atmosphere.

Some of them get reflected back into space.

The ones which get through the atmosphere warm the earth up.

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 animals and plants to survive.

Some of the gases act like a blanket, trapping heat. These gases are called ‘greenhouse gases’.

This is known as the ‘Natural Greenhouse Effect’. Without it, the earth would be much colder.

(the atmosphere is really much thinner than it looks above)

So why is global warming happening?

(the atmosphere is really much thinner than it looks above)

Some things that people do are increasing the amounts of the greenhouse gases in the atmosphere, so more heat is trapped.

The heating of the earth through human activities is called the ‘Enhanced Greenhouse Effect’ and this is causing the earth to heat up, or global warming.

Global warming doesn’t just mean that the earth gets hotter, it means that the whole climate is changing.

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 Ozone Water vapour Halocarbons

Human activity increases the amount of these gases in the atmosphere

How do humans increase carbon dioxide levels in the atmosphere?

Burning fossil fuels releases the carbon dioxide stored millions of years ago. Most of the increased carbon dioxide comes from fossil fuels

Deforestation releases the carbon stored in trees. Less trees also means less carbon dioxide can be removed from the atmosphere.

Ali Raza

Q1 Answers.

1. Green House EffectsExample : carbon dioxide (CO2), Methane, Ozone, Nitrous oxide, Sulfur Hexafluoride, Hydrofluorocarbons and etc.

Fig. 1: Cause for global warming: Carbon dioxide emissions in million tons per year over the last 200 years. (graph taken from http://www.globalwarmingart.com/wiki/Image:Global_Carbon_Emission_by_Type_png)

Fig 3: From which sectors do the major greenhouse gas emissions come from? The lower part of the picture shows the sources individually for the gases carbon dioxide, methane and nitrous oxide, respectively. (Graph from http://en.wikipedia.org/wiki/Image:Greenhouse_Gas_by_Sector.png)

Irfan Lodhra

Q1 Answers

2. Deforestationthe state of being clear of trees.

And the 2nd cause is,

In Other Words, It is an activity of cutting out trees in the forests in with the

purpose of development of that particular place,

resourcing the raw material to process goods like papers.

Therefore, Massive deforestation could lead to less carbon dioxide (CO2) being absorbed (for photosynthesis process) and causing much more of the greenhouse gases in the atmosphere.

Hmm.. I wonder how it looks like when a forest is

completely destroyed.

Pictures of Deforestation Activities

WHAAAATTTTT????!!!

Khalid Mehmood Shehzad

Effects

1. Rise In Sea Levels WorldwideThis happens due to the melting of two massive ice sheets

in Antartica and Greenland

Brown’s (2008) study indicates that if the Greenland ice sheet were to melt, it would raise the sea level up to 7 meters while the melting of West Antartic ice sheet would raise the sea level 5 meters. Even just a partial melting would have dramatic changes on the sea level

Well, that does not sound so bad.

Not that bad? Try press next and check out the

pictures buddy.

Pictures of Melting of The Ice Sheets

WHAAAATTTTT????!!!

Touqeer Aslam

Effects

2. More Killer Storms

The severity of storms such as hurricanes and cyclones is increasing,

and research published in Nature found that

(quoting) :

“Scientists have come up with the firmest evidence so far that global warming will significantly increases the intensity of the most extreme storms worldwide. The maximum wind speeds of the strongest tropical cyclones have increased significantly since 1981, according to research published by Nature this week. And the upward trend, thought to be driven by rising ocean temperatures, is unlikely to stop at any time soon”

Wow! That sounded like the it really is

dangerous! We got pictures for this one to show you too.

Pictures of Storms

Hurricane Ivan

Hurricane Katrina

View of cyclone from the sattelite

WHAAAATTTTT????!!!

Riaz Ahmad

Hi, my name is Friday and I have a conclusion of all this

mess for you. The earth is too old to stand up through this phenomena. Therefore, we, as the khalifa living in it are responsible to

ensure the beauty of the world can be enjoyed by our kids in the future. If we, as the soon-to-be-forefathers do not find a way to overcome this problem, imagine how would the future

generation survive with a climate that is hotter than it

already is now?

References

• http://www.wikihow.com/Take-Action-to-Reduce-Global-Warming

• http://www.scientificamerican.com/article.cfm?id=10-solutions-for-climate-change

• http://science.howstuffworks.com/nature/natural-disasters/hurricane8.htm

• http://www.nature.com/news/2008/080903/full/news.2008.1079.html

• http://sustainablog.org/2009/06/melting-ice-could-lead-to-massive-waves-of-climate-ref