Material from nine global climate models has been processed at SMHI’s climate research centre, Rossby Centre. The climate researchers have used Rossby Centre’s regional climate model RCA and three different scenarios for how the greenhouse effect will intensifiy in the future. The result is regional material in varying detail, indicating how the climate may change in the different regions. The extensive material is now available to researchers to analyse, to use in studies of climate effects and for climate adaptation.
“To have more than 100 simulations with the same regional climate model increases the usability of the material. These regional results are more comparable than if the global information had been processed with several different regional models”, says Gustav Strandberg, climate researcher at SMHI Rossby Centre.
Details appear regionally
The global climate scenarios show the climate development with large brush strokes, but usually they incorporate too few details to be useful in effect studies and for climate adaptation. More detailed patterns emerge by performing regional simulations. This becomes especially apparent in areas with varying terrain.
“Coast lines and mountain ranges indicate clear patterns in regional simulations as we “zoom in” more and then see more detail. This is visible in the precipitation patterns over the Alps and in Italy”, exemplifies Gustav Strandberg.
Examples of future temperature and precipitation
“We can see that the models agree in how the temperature and precipitation can develop in Europe during the winter at the end of the century”, says Grigory Nikulin, climate researcher at SMHI Rossby Centre.
Part of the CORDEX project
The new regional climate simulations are a part of CORDEX, a project within the World Climate Research Programme. The regional climate simulations are based on the new RCPs (Representative Concentration Pathways) and data from CMIP5, which also forms the basis of IPCC’s fifth climate report.
After IPCC’s fourth climate report in 2007 it became evident that there was a lack of detailed regional information concerning climate development in the world. In response to this CORD was created, a collaboration to compare the ability of different climate models to describe the climate and to produce climate projections to use in effect and adaptation studies.
Initially CORDEX focused on Africa, but simulations have now been made over a large part of the world’s land mass.
SMHI is one of the main partners in CORDEX. CORDEX stands for Coordinated Regional Climate Downscaling Experiment.
CMIP5 stands for Coupled Model Intercomparison Project Phase 5 and is a global collaboration concerning climate calculations. CMIP5 was established by the World Climate Research Programme.
Facts: SRES and RCP scenarios
There are two different types of scenarios, emissions scenarios and radiation scenarios.
Emissions scenarios are assumptions about the future discharge of greenhouse gases. The emissions scenarios are based on assumptions concerning the future development of the world’s economy, population growth, globalisation, a change to eco-friendly technologies, etc. The amount of greenhouse gases discharged depends on how the world develops. These scenarios are called SRES scenarios (Special Report on Emission Scenarios (Nakićenović, 2000)).
Radiation scenarios are based on assumptions about how the greenhouse effect will intensify in the future, known as radiative forcing (measured in W/m²). The greater the discharge of greenhouse gases, the greater the radiative forcing. Such scenarios are called RCP scenarios (Representative Concentration Pathways (Moss et al., 2010)).