What is a regional climate model ?
A Global Climate Model (GCM) can provide reliable climate information on global, continental and large regional scales covering what could be a vastly differing landscape (from very mountainous to flat coastal plains for example) with greatly varying potential for floods, droughts or other extreme events. Horizontal resolution limits the possibility to address smaller scale ranging from regional to local. Regional Climate Models (RCM) applied with higher spatial resolution over a limited area and driven by GCMs can provide more appropriate information on such smaller scales supporting more detailed impact and adaptation assessment and planning.
Why do we need regional climate modeling ?
Global Climate Models (GCM) can provide us with projections of how the climate of the Earth may change in the future. These results are the main motivation for the international community to take decisions on climate change mitigation. However, the impacts of a changing climate, and the adaptation strategies required to deal with them, will occur on more regional and national scales. This is where Regional Climate Models (RCMs) have an important role to play by providing projections with much greater detail and more accurate representation of localized extreme events.
What are regional climate projections in the CDS?
Regional climate projections are results from regional climate model simulations which have been generated by multiple independent climate research centres in the framework of the Coordinated Regional Climate Downscaling (CORDEX) supported by the World Climate Research Program (WCRP) and assessed by the Intergovernmental Panel on Climate Change (IPCC). These regional climate projections underpin the conclusion of the IPCC 5th Assessment Report that “Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems”.
The Coordinated Regional Climate Downscaling Experiment (CORDEX)
The CORDEX vision is to advance and coordinate the science and application of regional climate downscaling through global partnerships. It aims to evaluate regional climate model performance through a set of experiments aiming at producing regional climate projections. The goals of CORDEX are:
- To better understand relevant regional/local climate phenomena, their variability and changes, through downscaling,
- To evaluate and improve regional climate downscaling models and techniques,
- To produce coordinated sets of regional downscaled projections worldwide,
- To foster communication and knowledge exchange with users of regional climate information.
More information about CORDEX can be found at http://www.cordex.org/