12.1.1 Summary of knowledge from the Third Assessment Report
Climate trends in the 20th century
During the 20th century, most of Europe experienced increases in average annual surface temperature (average increase over the continent 0.8°C), with stronger warming over most regions in winter than in summer. The 1990s were the warmest in the instrumental record. Precipitation trends in the 20th century showed an increase in northern Europe (10 to 40%) and a decrease in southern Europe (up to 20% in some parts). The latest data reported in this assessment have confirmed these trends.
Climate change scenarios
The most recent climate modelling results available to the Third Assessment Report (TAR) showed an increase in annual temperature in Europe of 0.1 to 0.4°C/decade over the 21st century based on a range of scenarios and models. The models show a widespread increase in precipitation in the north, small decreases in the south, and small or ambiguous changes in central Europe. It is likely that the seasonality of precipitation will change and the frequency of intense precipitation events will increase, especially in winter. The TAR noted a very likely increase in the intensity and frequency of summer heatwaves throughout Europe, and one such major heatwave has occurred since the TAR.
Sensitivities to climate
With regards to its current sensitivities to climate, Europe was found to be most sensitive to the following conditions:
- extreme seasons, in particular exceptionally hot and dry summers and mild winters,
- short-duration events such as windstorms and heavy rains, and
- slow, long-term changes in climate which, among other impacts, will put particular pressure on coastal areas e.g., through sea-level rise.
More information is now available on the geographic variability of Europe’s sensitivity to changes in climate.
Variability of impacts in regions and on social groups
Impacts of climate change will vary substantially from region to region, and from sector to sector within regions. More adverse impacts are expected in regions with lower economic development which is often related to lower adaptive capacity. Climate change will have greater or lesser impacts on different social groups (e.g., age classes, income groups, occupations).
The TAR identified many climate change impacts on Europe’s economy:
- sea-level rise will affect important coastline industries,
- increasing CO2 concentrations may increase agricultural yields, although this may be counteracted by decreasing water availability in southern and south-eastern Europe,
- recreation preferences are likely to change (more outdoor activity in the north, less in the south),
- the insurance industry should expect increased climate-related claims, and
- warmer temperatures and higher CO2 levels may increase the potential timber harvest in northern Europe, while warmer temperatures may increase forest fire risk in southern Europe.