Battle against Global Warming: Battle against Global Warming: The Earth Radiation Balance The Earth Radiation Balance

FactorFactor

Submitted by –Submitted by –Suryaveer Singh (PGT Geography) Suryaveer Singh (PGT Geography) S.D.PUBLIC SCHOOL, BU BLOCK, S.D.PUBLIC SCHOOL, BU BLOCK,

PITAMPURA, DELHI -110088PITAMPURA, DELHI -110088

The Battle Against Global The Battle Against Global WarmingWarming

The Earth Radiation Balance The Earth Radiation Balance FactorFactor

Why we are here?Why we are here?

Learn the factors which causes Global Learn the factors which causes Global Warming, from astronomical to terrestrial .Warming, from astronomical to terrestrial .

We will be talking on radiation balance We will be talking on radiation balance specifically.specifically.

Research the relationships between Research the relationships between Greenhouse gases and the balance.Greenhouse gases and the balance.

To find solution and plan our actions to To find solution and plan our actions to control Global warming. control Global warming.

The bleak and Iceless futureThe bleak and Iceless future

Gangotri glacier is Gangotri glacier is shrinking 23m every shrinking 23m every year.year.

Polar ice caps are Polar ice caps are melting and breaking melting and breaking away due to global away due to global warming.warming.

Source: NASA

The symptoms of Global WarmingThe symptoms of Global Warming

The year 1998 The year 1998 recorded the warmest recorded the warmest temperature of the temperature of the millennium and some millennium and some of the worst floods of the worst floods around the world.around the world.

The Sahel region of The Sahel region of Sahara saw worst Sahara saw worst devastating drought.devastating drought.

(Source: Times of India)

Extreme weather eventsExtreme weather events

Ice Age cometh: it Ice Age cometh: it happened in the happened in the North Atlantic and North Atlantic and may happen again.may happen again.

According to According to scientists global scientists global warming could lead to warming could lead to prolonged chill.prolonged chill.

(Source: Earth Observatory)

Anthropogenic effect on climateAnthropogenic effect on climate

The most important effect on the climate is the The most important effect on the climate is the increasing trend in the concentration of increasing trend in the concentration of greenhouse gases greenhouse gases which are likely to cause which are likely to cause global warming.global warming.

They alter the process of earth radiation They alter the process of earth radiation balance by absorbing longwave radiation.balance by absorbing longwave radiation.

Earth’s Radiation BalanceEarth’s Radiation Balance

The earth as a whole does not accumulate or The earth as a whole does not accumulate or loose heat.loose heat.

It maintains its temperature.It maintains its temperature.

This happens only if the amount of heat This happens only if the amount of heat received in the form of insolation equals the received in the form of insolation equals the amount lost by the earth through terrestrial amount lost by the earth through terrestrial radiation. (Heat Budget)radiation. (Heat Budget)

The Earth’s Radiation BalanceAssume 100 units of incoming solar energy (insolation): (ncert, p. 65)

100 units6

reflectedby clouds

27 2

reflectedby ground

Backscattered

10Absorbed

by atmosphere

4absorbedby clouds

51absorbed by ground

• 14 units absorbed by atmosphere• 51 unitsabsorbed bysurface

• 35 unitsreflected (albedo)

albedo

The Radiation Balance: Longwave

Absorbed by CFCs, CH4, N2O, CO2, O3

17

23

Turbulanceand convection C

ondensa

tion

Emissionby GHGs

48

9 19

6

= 51

= 65

Direct radiationby earth

The Earth’s Heat Budget

17

23w

ind

Con

d.

48

9 19

6 27 2100

51

4

10

shortwave long wave total

+100 -100

+51 -51

6

Greenhouse EffectGreenhouse Effect

Certain Certain greenhouse gasesgreenhouse gases, such as , such as carbon dioxide, chlorofluorocarbons, carbon dioxide, chlorofluorocarbons, ozone, nitrous oxide and ozone, nitrous oxide and methanemethane, are , are able to absorb able to absorb longwave longwave radiationradiation emitted emitted from the Earth's surface. from the Earth's surface.

The The greenhouse effectgreenhouse effect aids in heating the aids in heating the Earth's atmosphere. Earth's atmosphere.

Rest is simple mathematicsRest is simple mathematics

The larger the The larger the concentration of concentration of greenhouse gases in greenhouse gases in the atmosphere, the the atmosphere, the higher will be absorption higher will be absorption of longwave radiation, of longwave radiation, thus resulting in thus resulting in increased temperature.increased temperature.

Annual quantity of longwaveRadiation absorbed in the aAtmosphere. (Image created Image created by the by the CoVis Greenhouse Effect Greenhouse Effect Visualizer).Visualizer).

Warming Up Warming Up

The amount of heat energy added to the The amount of heat energy added to the atmosphere by the atmosphere by the greenhouse effectgreenhouse effect is is controlled by the concentration of greenhouse controlled by the concentration of greenhouse gases in the Earth's atmosphere. gases in the Earth's atmosphere. All of the major greenhouse gases have All of the major greenhouse gases have increased in concentration since the beginning increased in concentration since the beginning of the of the Industrial RevolutionIndustrial Revolution (about 1700 AD). (about 1700 AD). As a result of these higher concentrations, As a result of these higher concentrations, scientists predict that the greenhouse effect will scientists predict that the greenhouse effect will be be enhancedenhanced and the Earth's climate will and the Earth's climate will become warmer. become warmer.

Other factors: SunspotsOther factors: Sunspots

When the number of When the number of sunspots decrease sunspots decrease warm and drier warm and drier conditions prevail on conditions prevail on the earth.the earth.

If they increase, If they increase, cooler and wetter cooler and wetter weather with greater weather with greater storminess occur.storminess occur.

Source: www.physicalgeography.net/)

Volcanism Volcanism

Eruptions throws up Eruptions throws up lots of aerosols into lots of aerosols into the atmosphere.the atmosphere.

They remain for a They remain for a considerable period of considerable period of time reducing the time reducing the sun’s radiation sun’s radiation reaching the Earth’s reaching the Earth’s surface.surface.

(Source: U.S. Geological Survey, photograph by Austin Post).

Efforts which can be done!Efforts which can be done!

Reduce emission of Reduce emission of greenhouse gases.greenhouse gases.

Adopting lifestyle Adopting lifestyle where there is no where there is no room for such gases.room for such gases.

Raising concerns for Raising concerns for the world community the world community to respond. to respond.

Lets do it!Lets do it!

Frequently Asked QuestionsFrequently Asked Questions

Terms to Remember (read handouts)Terms to Remember (read handouts)

Take home activityTake home activity

Test yourselfTest yourself

AcknowledgementsAcknowledgements

Whitlow, J.B. 2001. The Penguin Dictionary of Physical Whitlow, J.B. 2001. The Penguin Dictionary of Physical Geography. Second Edition. Penguin, Harmondsworth. Geography. Second Edition. Penguin, Harmondsworth. www.physicalgeography.net/fundamentalswww.physicalgeography.net/fundamentalsRichard H. Bryant. 1999. Physical Geography. Ninth Richard H. Bryant. 1999. Physical Geography. Ninth Edition. Rupa & Co., Delhi.Edition. Rupa & Co., Delhi.Barry, R.G., and Chorley, R.J., 1976. Atmosphere, Barry, R.G., and Chorley, R.J., 1976. Atmosphere, Weather and Climate. (Chapter 1). Third Edition, Weather and Climate. (Chapter 1). Third Edition, London.London.www.narc.nasa.gov/ www.narc.nasa.gov/ www.eosb.narc.nasa.gov/www.eosb.narc.nasa.gov/www.ocs.ou.edu/www.ocs.ou.edu/www.wikipedia.org/greenhouseeffect/www.wikipedia.org/greenhouseeffect/