Notes 111solar radiation, the rest being transmitted, the planet’s surface will receive
the same amount of energy as when the cloud is absent. Can you substantiate
the statement that the presence of low clouds tends to cool the Earth while
high clouds tend towards warming of it?
6 Associated with the melting of sea-ice which results in increased evapo-
ration from the water surface, additional low cloud can appear. How does
this affect the ice-albedo feedback? Does it tend to make it more or less
positive?
7 Work out the total energy received by the Earth from the Sun over the thirty-
seven-year period from 1957 to 1994; allow for that lost by reflection and
scattering to space. What preciseproportion of this is: (1) thetotal radiative
forcing over this period due to increased greenhouse gases (see for instance
Figure 3.8) and (2) the energy absorbed by the ocean as derived by Levitus
et al. (page 106)? Comment on your results.
8 It is sometimes argued that weather and climate models are the most sophis-
ticated and soundly based models in natural science. Compare them (e.g. in
their assumptions, their scientific basis, their potential accuracy, etc.) with
other computer models with which you are familiar both in natural science
and social science (e.g. models of the economy).
Notes for Chapter 5
1 Further information regarding the subject of this chapter can be found in the
following texts:
Houghton,J. T. 1991. The Bakerian Lecture,1991: The predictabilityof
weather and climate.Philosophical Transactions of the Royal Society, Lon-
don, A, 337 , pp. 521–71.
Houghton, J. T. 2002.The Physics of Atmospheres, third edition. Cambridge:
Cambridge University Press.
Houghton, J. T., Jenkins, G. J., Ephraums, J. J. (eds.) 1990.Climate Change:
the IPCC Scientific Assessments. Cambridge: Cambridge University
Press.
Houghton, J. T., Callander, B. A., Varney, S. K. (eds.) 1992.Climate Change
1992: the Supplementary Report to the IPCC Scientific Assessments. Cam-
bridge: Cambridge University Press.
Houghton, J. T., Meira Filho, L. G., Callander, B. A., Harris, N., Kattenberg,
A., Maskell, K. (eds.) 1996.Climate Change 1995: the Science of Climate
Change.Cambridge: Cambridge University Press.
Houghton, J. T., Ding, Y., Griggs, D. J., Noguer, M., van der Linden,P. J.,
Dai, X., Maskell, K., Johnson, C. A. (eds.) 2001.Climate Change 2001: the
Scientific Basis.Cambridge: Cambridge University Press.
McGuffie, K., Henderson-Sellers, A. 1997.A Climate Modelling Primer,
second edition. New York, Wiley.
Trenberth, K. E. (ed.) 1992.Climate System Modelling. Cambridge:
Cambridge University Press.