Coupled climate models
A climate model is a computer simulation of the real world, based on the laws of physics. We use these models to:
- forecast or project future weather and climate
- understand the processes that cause changes in our climate.
Scientists usually use separate software to simulate each part of the Earth system. For example, the oceans, atmosphere and ice regions. A coupled model brings these together to form a complete model of the Earth system.
Our ACCESS-S model, used for seasonal forecasting and attribution, is an example of a coupled model.
Sharing coupled model results
Scientists around the world compare and share coupled model results. This happens through the World Climate Research Programme's Coupled Model Intercomparison Project (CMIP).
This project started in 1995 and is now in its sixth phase (CMIP6). Early work is in progress to update the projections further with CMIP7.
Australia contributed two models to CMIP6 – ACCESS-CM2 and ACCESS-ESM1.5. We'll also submit model results for CMIP7. This will happen through a consortium led from the NESP Climate Systems Hub.
Using CMIP data
The CMIP database has model output from many institutions around the world.
For consistency, the institutions ran their models under common scenarios. This included:
- historical – 20th century
- futures ranging from low to high greenhouse gas emissions.
Researchers across Australia use a set of CMIP data products. These are stored at the National Computation Infrastructure (NCI). This includes CMIP5 and CMIP6 products.
The Australian Climate Service uses CMIP data to produce its down-scaled climate change projections – that is, high-resolution projections that provide more locally relevant information.