A prediction of the effects of an increase in climate-effective trace gases (C02, N20, CH4 and others) is only possible using model calculations based on certain "scenarios" of their increase (see Fig. 5.3.6A) and by coupling land, ocean and atmosphere processes to develop understanding of how the climate develops and changes. For Europe, such a model calculation (Parry 2000) has been made with the lower limit of C02 increase assumed to be 490 ppm and the upper limit to be 570 ppm in 2100. Since 1970 Europe has warmed up between 0.1 and 0.4 K per decade. It has been shown that the probability of a cold winter (one in 10 years) in northern Scandinavia would decrease to 0% by 2080. At the same time, the probability of a warm summer in northern and central Europe will decrease. However, the probability of a hot summer will increase in southern Europe. These temperature predictions show an increased effect of the Gulf Stream on Europe, with a change in precipitation as an immediate consequence. Ac cording to these predictions the Atlantic coast and northeast of Europe will become more humid, but central and southern Europe will become drier.
The predictions may be summarised as follows:
• warming will be greatest across north-eastern and southern Europe. Warming particularly affects winter temperatures (European Russia +0.15 to 0.6 K per decade). The warming in summer is less (0.08 to 0.3 K per decade for central Europe, 0.2 to 0.6 K for southern Europe). The probability that this warming will be a "natural trend" is 5%.
• precipitation is predicted to increase by 1-2% per decade in northern Europe and by 1% per decade in southern Europe. These changes are, to a large extent, within the range of natural variability. Winters will become moister and summers will show a steeper gradient between northern and southern Europe.
For land use in Europe the consequences will be:
• current differences in the water supply between northern und southern Europe will increase. This applies to extreme droughts as well as to an increased tendency of flooding in southern Europe.
• warming of northern Europe will have significant effects on soils (decomposition of humus), with the tree limit of conifers and deciduous species expanding northwards. The frequency of fires in southern Europe will increase.
• the NPP of managed forests in northern Europe will increase but decrease in southern Europe. Yields of agricultural crops are predicted to increase in northern Europe, in southern Europe the increasing drought will limit yields.
• several socio-economic consequences will occur because of the predicted increased gradient between northern and southern Europe. These include changes in the energy sector, changes in tourism (it will be too hot in southern Europe) and changes in the distribution of diseases.
Was this article helpful?