It follows from the discussion of computer models of the climate in Chapter 9, that predicting how the climate may change over the next century or so can be divided into two areas. The first is to decide how much is known about natural fluctuations in the climate and what this means for the future. The second is the whole question of how human activities will develop and what impact these will have on the climate. These issues are best considered separately and then, in the light of any conclusions reached, combined. In doing so, the objective will be to draw on all the material in this book to sum up how our knowledge on climate variability and climate change can be used to plan for the future.

NATURAL VARIABILITY

The relative stability of the climate throughout the Holocene poses a problem when considering how the climate may change over the next hundred years. It is all a matter of whether we can regard this stability as being the current natural order of things. If so, then an accurate measure of fluctuations over this period defines the current natural variability of the climate. If not, then we may have to include some elements of climate change, which occurred prior to the Holocene, in the analysis.