How do you choose the right climate model?

There are a variety of climate models, and their use depends on a variety of factors including: the area of study or the complexity of the model.

Some climate models represent particular climate processes with more detail than others. For a model to explore ocean processes it is not necessary to include vegetation and soil processes. Ignoring these processes allows the model to run faster, which can be an advantage.

Climate models vary depending on the processes they represent. It is important to choose the right model for the job.

Only some climate models represent soil and vegetation and their role in the carbon cycle with considerable detail. How soil and vegetation carbon is simulated does matter to the longer-term climate. Models which ignore these processes can risk having less accurate results.

If you are studying atmospheric processes, it is important to study aerosol particles in the atmosphere. While some models represent the chemical reactions involved and their interaction with cloud particles, others only include these effects through a simplified parameterisation.

Aerosols are tiny particles suspended in the atmosphere originating from sources such as volcanoes, the desert, sea salt and human activities such as sulphates from burning coal and oil. Aerosols can scatter and absorb sunlight and act as sites for chemical reactions. Adapted from Wang Hao.

Additionally, there are limitations resulting from the processes we can represent because of the computing time and the amount of data that the model produces. All models have strengths and weaknesses and choosing the right model or models for the right problem is essential. In general, it is rare to use the “best” climate model.

Often simulations using a number of models helps understand either a problem or the uncertainties associated with the problem. Ensembles of climate models can help with this.