This ppt presentation is made for physics undergraduate students for the curse Environmental physics.

1. The Energy Balance
A zero dimensional greenhouse model
•The sun makes life on earth possible. It is also the
driving force behind the changes in weather and
climate.
•Therefore studying the radiation balance between
incoming solar radiation and outgoing radiation from
the earth is important for climate modeling.

2. Cont…
• Atmospheric scientists derive from their
observations a simplified model for the
radiation balance between the surface and
atmosphere of the earth.
• The incoming solar radiation averaged
over the earth is given as 100 units. The
radiation is partly absorbed by the
atmosphere or partly scattered back or
reflected back to space.

3. Earth’s Energy Budget
(Model-1)

4. (Model- 2)

5. Earth’s Energy Budget
(Model-3)

6. Trends in Atmospheric Carbon Dioxide
November 2012: 392.81 ppm
November 2011: 390.24 ppm

7. 50 years trend of atmospheric CO2

8. Parameters of the zero dimensional
greenhouse model
Short Wave length Long Wave length
Parameter Symbol
& value
Parameter Symbol
& value
Albedo of
the surface
as =0.11 Transmittance of
the atmosphere
t’a =0.06
Albedo of the
atmosphere
aa =0.30 Albedo of the
atmosphere
a’a =0.31
Transmittanc
e of the
atmosphere
ta =0.53

9. Where is emissivity of the Earth
The earth’s radiation measured at
TOA is the intensity I
4
sI Tεσ=
ε
1for black bodyε =

10. Where is emissivity of the Earth
The earth’s radiation measured at
TOA is the intensity I
4
sI Tεσ=
ε
1for black bodyε =