GLOBAL WARMING

Prepared by: Peshawa YasinPrepared by: Peshawa Yasin

Index

IntroductionHistoryGreen house gasesGlobal Warming ImpactsControl

IntroductionHistoryGreen house gasesGlobal Warming ImpactsControl

Global WarmingAn average increase in

the temperature of the atmosphere near the Earth’s surface and in the troposphere, which can contribute to changes in global climate patterns

An average increase in the temperature of the atmosphere near the Earth’s surface and in the troposphere, which can contribute to changes in global climate patterns

• Since the late 1800’s, the global average temperature has increased about 0.7 to 1.4 degrees.

• The concentration of green house gases in the atmosphere were artificially raised by humans since past 250 years.

Green house effect: How does it work

The greenhouse effect insulates earth, resulting in the mild temperatures at the earth's surface that have allowed life to flourish.

The greenhouse effect is absolutely vital to allowing life, as we know it to survive on earth. Without the greenhouse effect, earth would be a cold planet, with a mean surface temperature well below freezing.

Thanks to the greenhouse effect the average global temperature of the earth is 15◦ C

The greenhouse effect insulates earth, resulting in the mild temperatures at the earth's surface that have allowed life to flourish.

The greenhouse effect is absolutely vital to allowing life, as we know it to survive on earth. Without the greenhouse effect, earth would be a cold planet, with a mean surface temperature well below freezing.

Thanks to the greenhouse effect the average global temperature of the earth is 15◦ C

Main Warming Mechanism: The Greenhouse Effect

Our earth receives most of its energy in the form of radiation from the sun

The incoming solar energy (Ultra Violet UV) has a very short wavelength and passes through the atmospheric gases unaffected to reach the earth surface

The earth surface absorbs the solar energy and releases it back to the atmosphere at a different wavelength as infrared (IR) radiation, some of which goes back into space

Our earth receives most of its energy in the form of radiation from the sun

The incoming solar energy (Ultra Violet UV) has a very short wavelength and passes through the atmospheric gases unaffected to reach the earth surface

The earth surface absorbs the solar energy and releases it back to the atmosphere at a different wavelength as infrared (IR) radiation, some of which goes back into space

Some of the IR radiation emitted by the earth is absorbed by greenhouse gases in the atmosphere.

These gases absorb the infrared radiation emitted by the earth and re-radiate the energy as heat back towards the earth causing a warming known as the greenhouse effect.

Some of the IR radiation emitted by the earth is absorbed by greenhouse gases in the atmosphere.

These gases absorb the infrared radiation emitted by the earth and re-radiate the energy as heat back towards the earth causing a warming known as the greenhouse effect.

Present Day Climate Change:

In the history of earth, climate change happened many times.

Ones more in the history of the earth, the climate is changing.

There is however several differences between past changes in the climate and what we are observing today:

In the history of earth, climate change happened many times.

Ones more in the history of the earth, the climate is changing.

There is however several differences between past changes in the climate and what we are observing today:

- Present climate change is occurring very rapidly as opposed to past climate changes which usually occurs over millions of years (rapid change have occurred in the past but has a result of catastrophic events only e.g. meteorite impact, large volcanic eruptions, sudden feedback)

- Present day climate change is not a natural event but a result of human activity

- Present day climate change can be prevented as we do know the causes and how to limit the impacts

- Present climate change is occurring very rapidly as opposed to past climate changes which usually occurs over millions of years (rapid change have occurred in the past but has a result of catastrophic events only e.g. meteorite impact, large volcanic eruptions, sudden feedback)

- Present day climate change is not a natural event but a result of human activity

- Present day climate change can be prevented as we do know the causes and how to limit the impacts

Brief History Of The Earth Climate: Natural Variability

The Earth is a very dynamic planet which has undergone many transformations throughout its history and since its formation 4.6 billion years ago.

A succession of geological events and the appearance of life have dramatically influenced the climate of the earth.

The Earth is a very dynamic planet which has undergone many transformations throughout its history and since its formation 4.6 billion years ago.

A succession of geological events and the appearance of life have dramatically influenced the climate of the earth.

HistoryThe field of Paleoclimatology has

provided information of climate change in the ancient past, supplementing modern observations of climate.

Climate variability usually occurs naturally on the planet over millions of years or suddenly as a result of a catastrophic event (e.g. major volcanic eruptions, meteor impacts).

The field of Paleoclimatology has provided information of climate change in the ancient past, supplementing modern observations of climate.

Climate variability usually occurs naturally on the planet over millions of years or suddenly as a result of a catastrophic event (e.g. major volcanic eruptions, meteor impacts).

Few ExamplesMiocene Climate: (23–15 MYA)

The climate during which was warmer than today's climate.

Early Cretaceous Climate: (145-65 MYA)The Early Cretaceous was a mild "Ice House"

world.

Early & Middle Jurassic Climate: (206-144 MYA)Deserts covered what is now the Amazon and

Congo rainforests.

Miocene Climate: (23–15 MYA) The climate during which was warmer than

today's climate.

Early Cretaceous Climate: (145-65 MYA)The Early Cretaceous was a mild "Ice House"

world.

Early & Middle Jurassic Climate: (206-144 MYA)Deserts covered what is now the Amazon and

Congo rainforests.

History

Late Devonian Climate: (360 MYA)Thick coals formed for the first time in the

tropical rainforests.

Early Permian Climate: (280 MYA)Much of the Southern Hemisphere was

covered by ice as glaciers pushed northward.

Late Devonian Climate: (360 MYA)Thick coals formed for the first time in the

tropical rainforests.

Early Permian Climate: (280 MYA)Much of the Southern Hemisphere was

covered by ice as glaciers pushed northward.

Example Of A Warmer Climate: Early & Middle Jurassic Climate (206 To 144 Million Years Ago)

The Jurassic is an example of a climate era which was much warmer than the climate that we are experiencing today.

Much of the Jurassic world was warm and moist, with a greenhouse climate.

The Jurassic is an example of a climate era which was much warmer than the climate that we are experiencing today.

Much of the Jurassic world was warm and moist, with a greenhouse climate.

Early & Middle Jurassic Climate

The polar areas were ice-free during this period.

The ocean surface stood at a higher level with respect to the continents.

Much of the earth was covered in warm and moist tropical forest

The polar areas were ice-free during this period.

The ocean surface stood at a higher level with respect to the continents.

Much of the earth was covered in warm and moist tropical forest

Example Of A Colder Climate: The Ordovician Climate (488 To 444

Million Years Ago)

The Ordovician is an example of a past climate which was much colder than the climate that we are experiencing today

Great Ice Age that gripped the earth at this time.

There were even glaciers in what is now the Sahara.

About 60% of animal genera became extinct,

The Ordovician is an example of a past climate which was much colder than the climate that we are experiencing today

Great Ice Age that gripped the earth at this time.

There were even glaciers in what is now the Sahara.

About 60% of animal genera became extinct,

Carbon dioxide (CO2)Methane (CH4)Nitrous oxide (N2O)Chlorofluorocarbon

(CFC)Water vapour (H2O)

GREENHOUSE GASES

GASES RESPONSIBLE

Carbon dioxide : It is generated by the human

activities like burning of coal, wood, natural gas.oil etc.

It is also released by animals & human beings during the process of respiration.

The trees take in the carbon dioxide, therefore deforestation is also an important reason for increase in carbon dioxide.

It accounts for 50% of the gases responsible for global warming.

Carbon dioxide : It is generated by the human

activities like burning of coal, wood, natural gas.oil etc.

It is also released by animals & human beings during the process of respiration.

The trees take in the carbon dioxide, therefore deforestation is also an important reason for increase in carbon dioxide.

It accounts for 50% of the gases responsible for global warming.

METHANEMETHANE

Methane accounts for 16% of all gases responsible for global warming .

It is estimated that nearly 30 to 200 million tones of methane is released every year.

The main source of methane is rice field.

Methane accounts for 16% of all gases responsible for global warming .

It is estimated that nearly 30 to 200 million tones of methane is released every year.

The main source of methane is rice field.

NITROUS OXIDENITROUS OXIDE

It is generated due to burning of biomass, agriculture, livestock waste, nitrogen rich fuels.

It accounts for 6% of the gases responsible for global warming.

It is generated due to burning of biomass, agriculture, livestock waste, nitrogen rich fuels.

It accounts for 6% of the gases responsible for global warming.

Chlorofluorocarbon [CFC]Chlorofluorocarbon [CFC]

It accounts for nearly 20% of the gases responsible for global warming.

These are non-toxic, nonflammable & highly stable compounds.

They are also used as coolants in compressors of air conditioners & refrigerators.

They are also use in insulators, fire extinguishers, aerosol etc.

It accounts for nearly 20% of the gases responsible for global warming.

These are non-toxic, nonflammable & highly stable compounds.

They are also used as coolants in compressors of air conditioners & refrigerators.

They are also use in insulators, fire extinguishers, aerosol etc.

Gas Major Source % Contribution

Carbon dioxide Fossil fuel & deforestation 50

Methane Fossil fuel, wood burning. 16

Nitrogen Oxide Wood burning, fertilizer, fossil fuel.

06

Chlorofluro carbons & other carbon

Industries, insulation, refrigeration.

20

What’s the proof that global warming is taking place?

Portage Glacier

1914 2004

AlaskaAlaska

Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org

Colorado RiverArizonaArizona

June 2002 Dec 2003

IMPACT OF CLIMATE CHANGE

Impact of rise in

temperature of 1.8oC

to 4oC

Ocean Life

Habitat

Weather

Sea level

Human Health

Crops

CO2 Emissio

n

Living Plants

Effects of Global WarmingIncreased Temperature

Habitat Damage and

Species AffectedChanges in Water Supply

Rising Sea Level

Effects Of Global

Warming

Human Society

Plants & Animals

Agriculture

Human Beings

Marine Life

EFFECT OF GLOBAL WARMING

On human Society:• Siberia & Canada might experience

increase in temperature from 10 to 12 degrees.

• The rainfall have increased by 2 to 3% per decade over tropical regions due to high rate of evaporation.

On Plants & Animals:• Slowly disappearing & eventually die

if the current trend in global warming countries.

• There are rapid rise in global temperature in next 100 years

• The wetland & coral reef may also undergo decline due to climatic changes

On Agriculture:• There may be negative effect on various

type of crop in different regions of the world.

• Soil moisture may decrease, water requirement of the crop will increase & will affect the crop yield.

• Due to Green house effect, several plants cripple down their size, fruits & leaves.

• It may lead to changes in rainfall pattern & some areas may become breeding ground for mosquitoes & some other insects which are vector of disease like malaria, dengue fever, yellow fever, etc.

• In low rainfall there will be waterborne disease.

• Heat waves are harmful to health.

• It may lead to changes in rainfall pattern & some areas may become breeding ground for mosquitoes & some other insects which are vector of disease like malaria, dengue fever, yellow fever, etc.

• In low rainfall there will be waterborne disease.

• Heat waves are harmful to health.

On Human Health:

On Ocean Life:• It is estimated that there will be rise in

sea level by 20 to30 cm by 2030.• Due to increase in the temperature, the

water expands & require more space.• It also occur as a result of melting of

glacier.• Due to global warming the ice extent &

snow cover have decreased.

ANALYZING GLOBAL WARMING

• Scientists use information from several sources to analyze global warming that occurred before people began to use thermometers.

• Computers help climatologists to analyze past climate change & predict the future changes.

Measures on controlling the problem

Government

* Set some laws to limit the amount of pollutants produced by factories

* Develop the skills of using renewable fuels, e.g. solar energy, wind energy

Government

* Set some laws to limit the amount of pollutants produced by factories

* Develop the skills of using renewable fuels, e.g. solar energy, wind energy

Measures on controlling the

problem

* Encourage the factories to replace fossil fuels by renewable fuels, which would not cause environmental pollution

* Carry out energy saving scheme → reduce the pollution produced by burning fossil fuels

* Planting more plants → reduce the pollutants e.g. CO2

* Encourage the factories to replace fossil fuels by renewable fuels, which would not cause environmental pollution

* Carry out energy saving scheme → reduce the pollution produced by burning fossil fuels

* Planting more plants → reduce the pollutants e.g. CO2

What’s being done now to reduce our emissions?

Solar Power Wind Power Fuel-Efficiency

Measures on controlling the

problemCitizens

* Reduce the use of plastic bags → as degradation of plastic emit CH4

* Recycle the resources, e.g. plastic

* Reduce the use of sprays → as CFCs would be emitted out

Citizens

* Reduce the use of plastic bags → as degradation of plastic emit CH4

* Recycle the resources, e.g. plastic

* Reduce the use of sprays → as CFCs would be emitted out

Measures on controlling the problem

* Reduce the use of air-conditioner, which will emit CFCs

* Use public transportation instead of private cars → reduce the pollutants emitted by cars

* Reduce the use of air-conditioner, which will emit CFCs

* Use public transportation instead of private cars → reduce the pollutants emitted by cars

Thanks