In describing the most significant examples of the economic impact of climatic change, a certain amount of information has been given about the overall nature of climatic change during the last millennium. By concentrating on the most dramatic events there is, however, a risk of presenting a partial picture of what happened. So it is important to have a balanced view of the current state of knowledge about past changes. Only then will we be able not only to put the ups and downs of the past into context but also start to form a view as to whether this knowledge can be applied in preparing for the future. In particular, without a better understanding of the extent of past natural climatic change it is not realistic to plan on the basis that current changes are the consequence of human activities. But, before considering the evidence of climatic change in recent centuries, we need to think the unthinkable.

Chaos round the corner?

The quest for a better understanding of the economic impact of climatic change on our current world has concentrated on relatively recent events. The far greater changes that have occurred over geologic timescales seem far too remote to bother about here.