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Educ

ation© Graphic Education 2007AS/OGGA01

GREENHOUSE EFFECT

WHAT IS THE GREENHOUSE EFFECT?1

The greenhouse effect is a natural process that keeps the Earth warm.

Heat energy

Refl ected energy

The greenhouse effect traps heat energy which is produced when energy from the sun strikes the Earth, as heat is trapped in a greenhouse. This is why it is called the greenhouse effect.

Atmosphere

Earth

Energy from the sun

Heat energy

Refl ected energy

When energy from the sun strikes the Earth, some is refl ected back into space and some is absorbed by the Earth.

The energy absorbed by the Earth becomes heat energy.

The enhanced greenhouse effectHumans have increased the level of greenhouse gases (methane and particularly carbon dioxide) in the atmosphere.

1.0º

0.0º

-1.0º

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

IndustrialRevolution

Years

Tem

pera

ture

in º

C As levels of atmospheric greenhouse gases increase so too does the amount of heat trapped. This makes the Earth hotter.

If the level of greenhouse gases becomes too high it could make the Earth too hot to sustain life.

The temperature of the Earth has increased since the industrial revolution. It is predicted that the temperature will continue to rise as more greenhouse gases are pumped into the atmosphere.

Atmosphere

Earth

Gre

enho

use

gase

s - C

arbo

n di

oxid

e, wate

r vapour, m

ethane, nitrous oxideRadiated heat energy escaping the atmosphere

The heat energy is then radiated from the Earth’s surface.

As the heat strikes the atmosphere some of it is absorbed by greenhouse gas molecules. This keeps the Earth warm.