modelling and projections

Climate models are based on our understanding of the physical and chemical interactions between the atmosphere, land surface, oceans and biosphere that create weather and climate.

Using this knowledge computer simulations of the climate are created using global climate models (GCMs). There are over 40 global climate models internationally which give estimations for the future climate across the globe based on different assumptions on how greenhouse gas concentrations will increase. with finer spatial detail are also used (where appropriate) to add value to climate change projections.This process is also called downscaling.

Australia plays a significant part in the global efforts to advance efforts in understanding the climate and projecting how it will evolve in the future. Australia’s ACCESS model (or the Australian Community Climate and Earth-System Simulator) has been developed by the Centre for Australian Weather and Climate Research (a collaborative venture between CSIRO and the Bureau of Meteorology). ACCESS, like other models, uses observations to constrain and test its performance. Evaluating model performance is an important step in understanding and improving climate change projections.

When it comes to using climate change projections for impact assessments, this website provides a number of tools to access projections for Australia, but there are a number of considerations that should be first taken into account. Considerations like what climate change scenarios are important to your system, what data do you need, what are the known climate change risks, what are the spatial and temporal limitations of the climate models and how confident are the projections for your variable or region of interest. There are some common mistakes when working with climate change projections that are necessary to consider.

Given that there are multiple sources of climate change projections information and data, it is important to consider the range of possible climate responses. The range of results from various climate models gives some indication of the plausible climate futures. Additionally there are a number of data sets and projects which provide climate change projection information for different purposes and these should be understood and considered when approaching a risk assessment.