Global Warming

INTRODUCTION

A Global Issue!

Global Warming is the biggest issue facing the world today.

In the next exhibition I provide information to help you understand that the planet has been warming, and the current warming of our

climate will bring major hardships and economic dislocations — untold human suffering, especially for our children and

grandchildren. We are already seeing significant costs from today's global warming which is caused by greenhouse gas pollution. Let`s

do something Once we all recognise we have a problem, there is a lot we can still

do to help the situation. Please do something and save our only place to live: Our Planet!

Index

The Greenhouse Effect on Earth

Water On Earth

Greenhouse Gases

Source of Water

CO2

The CO2 Cycle

Where Did O2 Come From?

Global Warming

Conclusion

The Greenhouse Effect on Earth

What is Greenhouse Effect?

The greenhouse effect is the heating of the surface of a planet or moon due to the presence of an atmosphere containing gases that absorb and emit infrared radiation. Thus, greenhouse gases trap heat within the surface-troposphere system. This mechanism is fundamentally different from that of an actual greenhouse, which works by isolating warm air inside the structure so that heat is not lost by convection.

Water On EarthSome of the most likely contributing factors

to the origin of the Earth's oceans are as follows:

The cooling of the primordial Earth to the point where the outgassed volatile components were held in an atmosphere of sufficient pressure for the stabilization and retention of liquid water.

Gradual leakage of water stored in hydrous minerals of the Earth's rocks.

Photolysis: radiation can break down chemical bonds on the surface.

Greenhouse Gases• The primary components of Earth’s atmosphere, N2 and

O2 do not have absorption in the IR wavelength range, therefore, do not have a significant role in setting the surface temperature of the planet…

• Greenhouse gas are efficient in absorbing IR light…The most important greenhouse gases are:– H2O – Water vapor.– CO2 – Carbon Dioxide– CH4 – methaneThe most abundant greenhouse gas in Earth’s

atmosphere is water vapor. Most of the greenhouse heating of Earth’s atmosphere is due to Water vapor absorption of IR radiation emitted by Earth, and then transferring the energy to the surrounding air molecule

Source of Water

• Mt. St Helen eruption, 2004!

The terrestrial planets were built from rock and planetesimals. No gases or water can condense at the high temperature near the Sun. So, where did the water on Earth come from? • The water on Earth (and other terrestrial worlds) most likely was brought over

by the comets during the period of heavy bombardment about 4 billion years ago…

• These water (and other gases) were trapped in the interior, and released by volcanic activities…by Outgassing

CO2CO2 is a colorless gas…• condenses into solid form (dry ice) at -78°C in atmospheric

pressure.• condenses into liquid at -57°C at pressure above 5.1

atmospheric pressure.

Atmospheric CO2 is derived from (The sources…)• Volcanic outgassing• burning of organic matter• Respiration of living organisms• …CO2 can be stored in (The Sinks…)• Highly soluble in water: forms H2CO3

• Dissolved CO2 in water can interact with silicate minerals to form carbonated minerals…

• …

The CO2 Cycle

If Earth warms up a bit, then • carbonate minerals form in the oceans at a higher

rate. • The rate at which the oceans dissolve CO2 gas

increases, pulling CO2 out of the atmosphere. • The reduced atmospheric CO2 concentration leads

to a weakened greenhouse effect that counteracts the initial warming and cools the planet back down.

If Earth cools a bit, • carbonate minerals form more slowly in the

oceans. • The rate at which the oceans dissolve CO2 gas

decreases, allowing the CO2 released by volcanism to build back up in the atmosphere.

• The increased CO2 concentration strengthens the greenhouse effect and warms the planet back up

The CO2 cycle acts as a thermostat that regulates the temperature of the Earth…

Where Did O2 Come From?The most important source of O2 on Earth is

Life and Photosynthesis. • Photosynthesis converts CO2 to O2, and

incorporates carbon into amino acids, proteins, and other components of living organisms.

• O2 will be depleted from the atmosphere very rapidly without a source.

• O2 is a very reactive chemical that likes to be combined with other elements through oxidation. For examples, CO2, H2O, FeO (rust) That’s how we make fire!

• O2 Absorbs UV, which also transform some of the O2 into O3, which absorbs even more UV O2 not only supports life, it also protect life!

UV light can break the water molecules to release oxygen, but the contribution is small….

Global Warming

There is a gradual increase in the average temperature of the Earth’s atmosphere in the last 100 years…It has risen about 1°C since 1900…• Are human activities

causing global warming?• What other (non-human)

factors can cause global warming?

• How does global warming affect our life? Just watch the movies…

Conclusion…• It looks like most of the scientists agree that the global warming

observed in the last century were caused by human activity. However, as we tried to demonstrate here, the global climate is a very complicated system. We understand the basic principle of the climate system, but we still don’t understand how nature regulates Earth’s climate over the long run, nor do we have the capability to create a realistic climate model and be able to predict with any certainty the effects of human activities on our climate system.

My advices…

• Keep an open mind.• Read, and think for yourself!• Do not rush into judgment (especially after you watch the movies). • Please trust the scientific community to come up with an honest

answer…There are enough check and balance in the scientific community to weed out the bad theories…

Task

1- Explain what is Greenhouse Effect2-Tell about the most important Greenhouse

gases3- Where did the water con Earth come from?4- How the CO2 regulates the temperature of

the Earth?.5- How we make fire?6- Go tho this page and explain about the

Layer Ozone.7- Join your classmate and watch this video

and make you own conclusions.

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W E B Q U E S T

WEBQUEST presented by:

Maria Dolly Giraldo Calle

Ambientes Tecnológicos de Inglés

FUNLAM

2009

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