Introduction

There are many reasons why global warming (GW) may not be perceived as a crisis in the traditional sense of the term. Although society is continuing to accumulate in the atmosphere ``greenhouse gases'' inducing global warming, there is a time lag (from decades to a century, i.e., longer than one human generation) before consequences of human action will be obvious. In addition, there are many scientific uncertainties obscuring the problem.

It is quite interesting to trace the evolution of this problem from S. Arrhenius [1], V. Kostitzin [2] and J. Callendar [3] up to present investigations. In fact, the social perception of global warming remains, essentially, the same as it was in the Kostitzin's and Callendar's time in spite of modelling and paleoclimatic reconstruction.

There is a tragic mismatch between social, economic and political time horizons on the one hand, and environmental horizons, on the other hand. While political leaders are elected every 4 - 6 years, the time scale of global warming consequences is around years.

There is another reason for inadequate political response connected to scientific uncertainties: GCMs (General Circulation Models) have a poor record in producing scenarios (especially for precipitation) for the regions of the Earth, while national, regional and local decision makers need to know what global values will mean at their, local scale of action [4].

It is obvious that the choice of any particular strategy depends on the particular social perception of GW. It seems to us (and as mentioned above), GW is not (yet) perceived as a global crisis or a global disaster. First of all, any climatic extreme event is perceived at regional and local levels, even if it has a global origin. The event is considered as an extreme one if it is accompanied by serious social perturbations. For instance, the hot summer of 1988 in the USA was an extreme event since

1. navigation on large rivers broke down so that water transport had to be replaced by trains and trucks;
2. big losses took place at hydropower plants;
3. disturbances in industrial and urban water supply, agricultural losses, etc. were triggered.

The most serious problems were connected to navigation, though from a common sense viewpoint it would seem that agricultural losses should be the most important [5]. However, a long drought would be a disaster for any rural region with agriculture as the main sector of economy.