By representing these processes, climate models can simulate how the Earth’s climate system functions and how it has evolved through time. Climate Models are also used to help create projections of how the Earth’s climate system may change in the future under different scenarios. Many different groups of scientists around the world have been improving our understanding of how our complex climate system works.
For a number of reasons, climate models have to be run over the historical period before the future simulations can begin. One such reason is that this gives scientists the opportunity to compare the model simulations with historical observations.
On ClimateData.ca, the simulations produced by these models that cover the period from 1950 to 2005 are called modelled historical simulations. The better the models represent historical climate, the more confidence scientists have in the models’ ability to project the future.
Because modelled historical data is simulated data, the daily, monthly, and annual values of weather events will not be exactly the same as those in the observed historical dataset, although the climatological monthly, seasonal and annual averages and variations are similar when regional or larger scale averages are considered. Because models and meteorological observations do not generally represent information at the same spatial scales, it is important to use modelled historical data when making direct comparisons with modelled future data.
ClimateData.ca provides historical climate simulations from 24 different climate models generated by scientists from around the world. The historical period from these climate simulations can be viewed by clicking on any grid box on the map or by choosing the Location feature. The historical simulations are shown in grey on the graphs that appear.