Factsheet 1: Understanding the Data
The Queensland Future Climate: Understanding the data web page explains how climate projections work and provides guidance on how to interpret and apply the projections data to meet your needs. This factsheet includes some extracts from the web page, but you are encouraged to visit the Understanding the data web page to access the full suite of information and animated graphics that explain the processes used to generate the projections, the benefits of Queensland's approach to downscaling, and the assumptions and limitations.
It's important to understand that the climate projections data provided by sites such as Queensland Future Climate are not predictions or forecasts, but are simulations of plausible futures based on a range of assumptions and scenarios.
Climate Models
Global climate models are computer simulations of the Earth's climate system that attempt to replicate key processes in the atmosphere, oceans, land and ice. These simulations can be used to recreate the past climate or construct projections of the future climate under various assumptions. Climate models have been used to simulate the climate system's response to human-induced increases in greenhouse gases and other factors as summarised in the assessment reports produced by the Intergovernmental Panel on Climate Change (IPCC).
The most recent projections for Queensland are based on the modelling completed by the Coupled Model Intercomparison Project Phase 6 (CMIP6) that supported the development of the Sixth Assessment Report (AR6) from the IPCC. However, projections for Queensland based on the previous CMIP5 modelling are also available. Other factsheets on this page explain the differences between CMIP5 and CMIP6, and also provide more details on the climate models used.
The Benefits of Dynamical Downscaling
The high-resolution climate change projections available on Queensland Future Climate were produced using a dynamical downscaling approach. Dynamical downscaling approaches use output from the Global Climate Model as well as refined elevation, land cover and coastline data to build a Regional Climate Model and significantly improve the spatial resolution of climate change projections. Dynamic downscaling is different to other methods, such as statistical downscaling, which is based on statistical relationships between large- and small-scale variables.
In the dynamical downscaling approach, Queensland used a global variable-resolution climate model called CCAM (Conformal-Cubic Atmospheric Model) developed by CSIRO. The downscaling process provides a spatial resolution of about 10 km over the Queensland region. These high-resolution simulations were completed for the period 1980 to 2099.
Reducing Uncertainty
The main advantage of illustrating results from all models is to provide transparency. This is vital when using the data to estimate future climate risk. For example, showing the output from all models allows users to not just look at mean performance, but the full extent of the range of projections. This is more informative than just focusing on the median (50th percentile) and allows output for the upper (90th percentile) and lower (10th percentile) bounds to be considered as well. This allows for more realistic scenario-based testing of a plausible range of future climates.
