The climate system consists of five main components – atmosphere, ocean, ice, soil, and ecosystems. These components mutually influence each other. Actual climate data only provides information about the past and present.
Climate models are used to simulate what the climate will be like. Through so-called climate projections, calculations of climatic conditions are carried out for the future, including calculation of greenhouse gas emissions. Through calculations of emissions from for example coal power and natural gas, and the effects these will have on the amount of greenhouse gases, you can compare the consequences of using different energy sources.
The various models used each have their strengths and weaknesses, and will be able to produce different results. By comparing calculations from several models, more reliable results are obtained. In the World Climate Research Program “WCRP”, such comparisons are made in project CMIP (Coupled Model Intercomparison Project). This also includes data from the Norwegian Earth System Model NorESM. The Nansen Center has participated in the development of NorESM, and uses this model to study regional and global climate contexts. Through the CMIP project, the center contributes research results to the UN’s Intergovernmental Panel on Climate Change.