The information presented in the following pages shows how the climate could possibly develop in the next 100 years (the average for 2071-2100 compared to the average for 1961-1990) in the Baltic Sea Region. The material is based on calculations from climate models that use information about future changes in the atmosphere. Climate models include the relationships between physical processes in the whole system atmosphere-land-water. The results from the calculations with the climate models cover the period 1961-2100.
Two greenhouse gas emissions scenarios were used for the analysis:
SRES A2 (representing a rapid population growth and intensive energy use) and
SRES B2 (representing a slower population growth and lower energy use).
Emission scenarios are based on the assumption of the future development of the world economy, population increase, globalisation, change to environmentally friendly technology, among other things. The amount of greenhouse gases that will be emitted over time depends on how the world develops. The emission scenarios are described in IPCC’s report (2000): Special Report on Emissions Scenarios (SRES).
Read more about emission scenarios in the section About climate change.
In this study a regional atmospheric model from the Rossby Centre in Sweden, RCA3, has been applied. The model covers Europe and the size of the squares in the grid over the land area (resolution) is approximately 50x50 km.
Read more about climate models in the section About climate change.
The climate models have been run from 1961 to 2100. The meteorological period 1961-1990 was used for the validation of the models. The model results from this period are compared with measured temperature and precipitation values to determine how good the model is at representing the current climate. The period 1961-1990 is then used as a reference which the future climate is then compared to.
Read more about climate scenarios in the section About climate change.
The results that are presented here are based on two emission scenarios (SRES A2 and SRES B2) and one global climate model. The global results are downscaled with one regional climate model (RCA3). When one analyses this material it is important to think that only two of the many probable model calculations are presented. Other emission scenarios and other global and regional models can give somewhat different results. This is especially true about the quantitative results (e.g. how much rain or how much temperature will increase). For example studies have shown that the climate model ECHAM4 gives a temperature and precipitation change during winter in northern Europe that is larger than in many other climate models.
Another source of uncertainty is natural variability. It is not to be expected that the climate in the model is in phase with the real climate. On the other hand a good quality climate model should calculate good average values and characteristic variability, e.g. the right number of cold and warm winters during a 30-year period. The cold and warm winters could nevertheless occur in another sequence than in the observed climate.
Read more about uncertainty in the section About climate change.
Summary of the main changes of selected climate parameters
In the following sections some of the parameters produced by the regional climate model (RCA3) are presented for the Baltic Sea region. The Baltic Sea region is displayed to serve the requirements of the project BalticClimate focussing on all 11 countries of the Baltic Sea Region Programme 2007-2013. The parameters are plotted as seasonal means and as anomalies where the mean for the period 2071-2100 is compared with the mean for the period 1961-1990. Two scenarios (SRES A2 and SRES B2) are plotted for each selected parameter.
These parameters are selected because they are considered to be of common interest and to express different important sides of climate change:
The text and figures of the climate change scenarios can be downlowded as a PDF file from the Related files on the right.