The Atmosphere and Climate Modeling - Introduction to Carbon Capture and Sequestration - page 51

(a) (b)

Figure 2.2.3 With and without an atmosphere
(a) A picture of the moon which is considered to not have an atmosphere. Without an
atmosphere, the earth would have a temperature of 107ºC during the day and at
night − 153ºC, giving an average temperature of − 23ºC. Image of the moon from
NASA , https://solarsystem.nasa.gov/planets/profi le.cfm?Object=Moon
(b) Because of the greenhouse gasses, the average temperature of the earth is 14ºC.
Image of the earth from NASA , http://blogs.smithsonianmag.com/science/
fi les/2010/04/modis_wonderglobe_lrg.jpg

Question 2.2.1 What about fossil fuels?

In our calculations of the temperature of the earth we ignored the fact that
we are burning fossil fuels. If we assume all fossil fuel energy eventually is
converted into heat, how does this energy compare with the energy we
receive from the sun?

natural greenhouse effect . If we take this effect into account in calculat-
ing the earthshine, we can explain why the actual temperature of the
surface of the earth is much higher than

19ºC. Given that the average
temperature of the earth is 14ºC, Stefan-Boltzmann's law tells us that the
earth is emitting about 390 W/m 2 . As we recall from Figure 2.2.2 , the
surface of the earth is receiving 161 W/m 2 from the sun. As the net
energy balance for the earth is zero, the difference is the greenhouse
effect. This effect is huge. It is interesting to compare this effect to the
heating caused by the burning of fossil fuels (see Question 2.2.1 ).

−