Long-Term Monitoring: Why, What, Where, When & How?

One major factor fuelling public concern over environmental deterioration is the uncertainty surrounding the main issues: global warming, ozone depletion, pollution, destruction of natural habitats. Ideally, we would tackle these issuesof changing environments by first understanding the natural environment sufficiently in order to identify the change. We are facing the urgent need to understand changes to natural systems when we have little understanding of their former state. There are several main reasons for our being inadequately prepared:-- Natural systems are complex - understanding them demands enormous scientific efforts on a larger scale than has previously proved possible. -- Natural systems are characterised by a high degree of variation - on time-scales of hours to thousands of years. -- We lack the necessary long-term observations - to adequately understand the background for assessing the perceived threat from environmental change.We are forced into making estimates of environmental change in the absence of adequate background information. In practice this involves using available, mostly short-term, observations to answer questions requiring longer-term series of data, with a heavy reliance on modelling to help make up for the shortfall. This inevitably produces large amounts of uncertainty in any predictions generated by the models.What can we do to reduce the levels of uncertainty regarding environmental issues? The obvious need for more longer-term observations cannot be met instantaneously. However, if more such records would have helped us to understand present-day environmental changes and improved our ability to predict future changes, as seems to be the case, we should at least consider the possibilities for maintaining the few long-term series of observations we have in place and starting new series where needed. This was the subject of an international workshop leading to the publication of this book.