230 Weighingthe uncertainty
for instance, the installation of mirrors in space to cool the Earth by
reflecting sunlight away from it; the addition of dust to the upper at-
mosphere to provide a similar cooling effect and the alteration of cloud
amount and type by adding cloud condensation nuclei to the atmosphere.
None of these has been demonstrated to be either feasible or effective.
Further, they suffer from the very serious problem that none of them
would exactly counterbalance the effect of increasing greenhouse gases.
As has been shown, the climate system is far from simple. The results
of any attempt at large-scale climate modification could not be perfectly
predicted and might not be what is desired. With the present state of
knowledge, artificial climate modification along any of these lines is not
an option that needs to be considered.
The conclusion from this section – and the last one – is that to ‘wait
and see’ would be an inadequate and irresponsible response to what we
know. The FrameworkConvention on Climate Change (FCCC) signed
in Rio (see box on page 243 in Chapter 10) recognised that some action
needs to be taken now. Just what that action should be and how it fits in
to a sensiblescheme of sequential decision making will be the subject
of the next chapter.Principles for international action
From the three previous sections, four distinct principles can be iden-
tified to form the basis of international action. They are all contained
in the Rio Declaration on Environment and Development (see box be-
low) agreed by over 160 countries at the United Nations Conference
on Environment and Development (the ‘Earth Summit’) held in Rio
de Janeiro in 1992. They can also be identified in one form or an-
other in the FCCC (see box on page 243 in Chapter 10). The Prin-
ciples (with references to the Principles of the Rio Declaration and the
Articles of the FCCC) are:
The Precautionary Principle (Principle 15)
The Principle of Sustainable Development (Principles 1 and 7)
The Polluter-Pays Principle (Principle 16)
The Principle of Equity – International and Intergenerational (Princi-
ples 3 and 5)In the next chapter we shall consider how these principles can be applied.Some global economics
So far in this chapter, our attempt to balance uncertainty against the need
for action has been considered in terms of issues. Is it possible to carry